来源:https://developer.android.com/reference/android/graphics/Bitmap
Bitmap
public final class Bitmap
extends Object
implements Parcelable
java.lang.Object | |
↳ | android.graphics.Bitmap |
Summary
Nested classes |
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enum |
Bitmap.CompressFormat Specifies the known formats a bitmap can be compressed into |
enum |
Bitmap.Config Possible bitmap configurations. |
Constants |
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int |
DENSITY_NONE Indicates that the bitmap was created for an unknown pixel density. |
Inherited constants |
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From interface |
Fields |
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public static finalCreator<Bitmap> |
CREATOR |
Public methods |
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boolean |
compress(Bitmap.CompressFormat format, int quality, OutputStream stream) Write a compressed version of the bitmap to the specified outputstream. |
Bitmap |
copy(Bitmap.Config config, boolean isMutable) Tries to make a new bitmap based on the dimensions of this bitmap, setting the new bitmap's config to the one specified, and then copying this bitmap's pixels into the new bitmap. |
void |
copyPixelsFromBuffer(Buffer src) Copy the pixels from the buffer, beginning at the current position, overwriting the bitmap's pixels. |
void |
copyPixelsToBuffer(Buffer dst) Copy the bitmap's pixels into the specified buffer (allocated by the caller). |
static Bitmap |
createBitmap(Bitmap source, int x, int y, int width, int height) Returns an immutable bitmap from the specified subset of the source bitmap. |
static Bitmap |
createBitmap(int[] colors, int width, int height, Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. |
static Bitmap |
createBitmap(Bitmap source, int x, int y, int width, int height, Matrix m,boolean filter) Returns an immutable bitmap from subset of the source bitmap, transformed by the optional matrix. |
static Bitmap |
createBitmap(DisplayMetrics display, int width, int height, Bitmap.Configconfig, boolean hasAlpha, ColorSpace colorSpace) Returns a mutable bitmap with the specified width and height. |
static Bitmap |
createBitmap(Bitmap src) Returns an immutable bitmap from the source bitmap. |
static Bitmap |
createBitmap(Picture source) Creates a Bitmap from the given |
static Bitmap |
createBitmap(DisplayMetrics display, int[] colors, int offset, int stride,int width, int height, Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. |
static Bitmap |
createBitmap(DisplayMetrics display, int[] colors, int width, int height,Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. |
static Bitmap |
createBitmap(DisplayMetrics display, int width, int height, Bitmap.Configconfig) Returns a mutable bitmap with the specified width and height. |
static Bitmap |
createBitmap(int[] colors, int offset, int stride, int width, int height,Bitmap.Config config) Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. |
static Bitmap |
createBitmap(Picture source, int width, int height, Bitmap.Config config) Creates a Bitmap from the given |
static Bitmap |
createBitmap(int width, int height, Bitmap.Config config, boolean hasAlpha, ColorSpace colorSpace) Returns a mutable bitmap with the specified width and height. |
static Bitmap |
createBitmap(DisplayMetrics display, int width, int height, Bitmap.Configconfig, boolean hasAlpha) Returns a mutable bitmap with the specified width and height. |
static Bitmap |
createBitmap(int width, int height, Bitmap.Config config) Returns a mutable bitmap with the specified width and height. |
static Bitmap |
createBitmap(int width, int height, Bitmap.Config config, boolean hasAlpha) Returns a mutable bitmap with the specified width and height. |
static Bitmap |
createScaledBitmap(Bitmap src, int dstWidth, int dstHeight, boolean filter) Creates a new bitmap, scaled from an existing bitmap, when possible. |
int |
describeContents() No special parcel contents. |
void |
eraseColor(int c) Fills the bitmap's pixels with the specified |
Bitmap |
extractAlpha() Returns a new bitmap that captures the alpha values of the original. |
Bitmap |
extractAlpha(Paint paint, int[] offsetXY) Returns a new bitmap that captures the alpha values of the original. |
int |
getAllocationByteCount() Returns the size of the allocated memory used to store this bitmap's pixels. |
int |
getByteCount() Returns the minimum number of bytes that can be used to store this bitmap's pixels. |
ColorSpace |
getColorSpace() Returns the color space associated with this bitmap. |
Bitmap.Config |
getConfig() If the bitmap's internal config is in one of the public formats, return that config, otherwise return null. |
int |
getDensity() Returns the density for this bitmap. |
int |
getGenerationId() Returns the generation ID of this bitmap. |
int |
getHeight() Returns the bitmap's height |
byte[] |
getNinePatchChunk() Returns an optional array of private data, used by the UI system for some bitmaps. |
int |
getPixel(int x, int y) Returns the |
void |
getPixels(int[] pixels, int offset, int stride, int x, int y, int width,int height) Returns in pixels[] a copy of the data in the bitmap. |
int |
getRowBytes() Return the number of bytes between rows in the bitmap's pixels. |
int |
getScaledHeight(int targetDensity) Convenience method that returns the height of this bitmap divided by the density scale factor. |
int |
getScaledHeight(Canvas canvas) Convenience for calling |
int |
getScaledHeight(DisplayMetrics metrics) Convenience for calling |
int |
getScaledWidth(int targetDensity) Convenience method that returns the width of this bitmap divided by the density scale factor. |
int |
getScaledWidth(DisplayMetrics metrics) Convenience for calling |
int |
getScaledWidth(Canvas canvas) Convenience for calling |
int |
getWidth() Returns the bitmap's width |
boolean |
hasAlpha() Returns true if the bitmap's config supports per-pixel alpha, and if the pixels may contain non-opaque alpha values. |
boolean |
hasMipMap() Indicates whether the renderer responsible for drawing this bitmap should attempt to use mipmaps when this bitmap is drawn scaled down. |
boolean |
isMutable() Returns true if the bitmap is marked as mutable (i.e. can be drawn into) |
boolean |
isPremultiplied() Indicates whether pixels stored in this bitmaps are stored pre-multiplied. |
boolean |
isRecycled() Returns true if this bitmap has been recycled. |
void |
prepareToDraw() Builds caches associated with the bitmap that are used for drawing it. |
void |
reconfigure(int width, int height, Bitmap.Config config) Modifies the bitmap to have a specified width, height, and |
void |
recycle() Free the native object associated with this bitmap, and clear the reference to the pixel data. |
boolean |
sameAs(Bitmap other) Given another bitmap, return true if it has the same dimensions, config, and pixel data as this bitmap. |
void |
setConfig(Bitmap.Config config) Convenience method for calling |
void |
setDensity(int density) Specifies the density for this bitmap. |
void |
setHasAlpha(boolean hasAlpha) Tell the bitmap if all of the pixels are known to be opaque (false) or if some of the pixels may contain non-opaque alpha values (true). |
void |
setHasMipMap(boolean hasMipMap) Set a hint for the renderer responsible for drawing this bitmap indicating that it should attempt to use mipmaps when this bitmap is drawn scaled down. |
void |
setHeight(int height) Convenience method for calling |
void |
setPixel(int x, int y, int color) Write the specified |
void |
setPixels(int[] pixels, int offset, int stride, int x, int y, int width,int height) Replace pixels in the bitmap with the colors in the array. |
void |
setPremultiplied(boolean premultiplied) Sets whether the bitmap should treat its data as pre-multiplied. |
void |
setWidth(int width) Convenience method for calling |
void |
writeToParcel(Parcel p, int flags) Write the bitmap and its pixels to the parcel. |
Inherited methods |
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From class |
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From interface |
Constants
DENSITY_NONE
added in API level 4
public static final int DENSITY_NONE
Indicates that the bitmap was created for an unknown pixel density.
See also:
Constant Value: 0 (0x00000000)
Fields
CREATOR
added in API level 1
public static final Creator<Bitmap> CREATOR
Public methods
compress
added in API level 1
public boolean compress (Bitmap.CompressFormat format, int quality, OutputStream stream)
Write a compressed version of the bitmap to the specified outputstream. If this returns true, the bitmap can be reconstructed by passing a corresponding inputstream to BitmapFactory.decodeStream(). Note: not all Formats support all bitmap configs directly, so it is possible that the returned bitmap from BitmapFactory could be in a different bitdepth, and/or may have lost per-pixel alpha (e.g. JPEG only supports opaque pixels).
This method may take several seconds to complete, so it should only be called from a worker thread.
Parameters | |
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format |
Bitmap.CompressFormat : The format of the compressed image |
quality |
int : Hint to the compressor, 0-100. 0 meaning compress for small size, 100 meaning compress for max quality. Some formats, like PNG which is lossless, will ignore the quality setting |
stream |
OutputStream : The outputstream to write the compressed data. |
Returns | |
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boolean |
true if successfully compressed to the specified stream. |
copy
added in API level 1
public Bitmap copy (Bitmap.Config config, boolean isMutable)
Tries to make a new bitmap based on the dimensions of this bitmap, setting the new bitmap's config to the one specified, and then copying this bitmap's pixels into the new bitmap. If the conversion is not supported, or the allocator fails, then this returns NULL. The returned bitmap has the same density and color space as the original.
Parameters | |
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config |
Bitmap.Config : The desired config for the resulting bitmap |
isMutable |
boolean : True if the resulting bitmap should be mutable (i.e. its pixels can be modified) |
Returns | |
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Bitmap |
the new bitmap, or null if the copy could not be made. |
Throws | |
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IllegalArgumentException |
if config is Bitmap.Config.HARDWARE and isMutable is true |
copyPixelsFromBuffer
added in API level 3
public void copyPixelsFromBuffer (Buffer src)
Copy the pixels from the buffer, beginning at the current position, overwriting the bitmap's pixels. The data in the buffer is not changed in any way (unlike setPixels(), which converts from unpremultipled 32bit to whatever the bitmap's native format is. The pixels in the source buffer are assumed to be in the bitmap's color space.
After this method returns, the current position of the buffer is updated: the position is incremented by the number of elements read from the buffer. If you need to read the bitmap from the buffer again you must first rewind the buffer.
Parameters | |
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src |
Buffer |
Throws | |
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IllegalStateException |
if the bitmap's config is Bitmap.Config.HARDWARE |
copyPixelsToBuffer
added in API level 1
public void copyPixelsToBuffer (Buffer dst)
Copy the bitmap's pixels into the specified buffer (allocated by the caller). An exception is thrown if the buffer is not large enough to hold all of the pixels (taking into account the number of bytes per pixel) or if the Buffer subclass is not one of the support types (ByteBuffer, ShortBuffer, IntBuffer).
The content of the bitmap is copied into the buffer as-is. This means that if this bitmap stores its pixels pre-multiplied (see isPremultiplied()
, the values in the buffer will also be pre-multiplied. The pixels remain in the color space of the bitmap.
After this method returns, the current position of the buffer is updated: the position is incremented by the number of elements written in the buffer.
Parameters | |
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dst |
Buffer |
Throws | |
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IllegalStateException |
if the bitmap's config is Bitmap.Config.HARDWARE |
createBitmap
added in API level 1
public static Bitmap createBitmap (Bitmap source, int x, int y, int width, int height)
Returns an immutable bitmap from the specified subset of the source bitmap. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density and color space as the original bitmap.
Parameters | |
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source |
Bitmap : The bitmap we are subsetting This value must never be |
x |
int : The x coordinate of the first pixel in source |
y |
int : The y coordinate of the first pixel in source |
width |
int : The number of pixels in each row |
height |
int : The number of rows |
Returns | |
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Bitmap |
A copy of a subset of the source bitmap or the source bitmap itself. |
Throws | |
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IllegalArgumentException |
if the x, y, width, height values are outside of the dimensions of the source bitmap, or width is <= 0, or height is <= 0 |
createBitmap
added in API level 1
public static Bitmap createBitmap (int[] colors, int width, int height, Bitmap.Config config)
Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. Its initial density is as per getDensity()
. The newly created bitmap is in the sRGB
color space.
Parameters | |
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colors |
int : Array of sRGB colors used to initialize the pixels. This array must be at least as large as width * height. This value must never be |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. If the config does not support per-pixel alpha (e.g. RGB_565), then the alpha bytes in the colors[] will be ignored (assumed to be FF) |
Returns | |
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Bitmap |
Throws | |
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IllegalArgumentException |
if the width or height are <= 0, or if the color array's length is less than the number of pixels. |
createBitmap
added in API level 1
public static Bitmap createBitmap (Bitmap source, int x, int y, int width, int height, Matrix m, boolean filter)
Returns an immutable bitmap from subset of the source bitmap, transformed by the optional matrix. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density and color space as the original bitmap. If the source bitmap is immutable and the requested subset is the same as the source bitmap itself, then the source bitmap is returned and no new bitmap is created.
Parameters | |
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source |
Bitmap : The bitmap we are subsetting This value must never be |
x |
int : The x coordinate of the first pixel in source |
y |
int : The y coordinate of the first pixel in source |
width |
int : The number of pixels in each row |
height |
int : The number of rows |
m |
Matrix : Optional matrix to be applied to the pixels This value may be |
filter |
boolean : true if the source should be filtered. Only applies if the matrix contains more than just translation. |
Returns | |
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Bitmap |
A bitmap that represents the specified subset of source |
Throws | |
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IllegalArgumentException |
if the x, y, width, height values are outside of the dimensions of the source bitmap, or width is <= 0, or height is <= 0 |
createBitmap
added in API level 26
public static Bitmap createBitmap (DisplayMetrics display, int width, int height, Bitmap.Config config, boolean hasAlpha, ColorSpace colorSpace)
Returns a mutable bitmap with the specified width and height. Its initial density is determined from the given DisplayMetrics
. The newly created bitmap is in the sRGB
color space.
Parameters | |
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display |
DisplayMetrics : Display metrics for the display this bitmap will be drawn on. This value may be |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. This value must never be |
hasAlpha |
boolean : If the bitmap is ARGB_8888 or RGBA_16F this flag can be used to mark the bitmap as opaque. Doing so will clear the bitmap in black instead of transparent. |
colorSpace |
ColorSpace : The color space of the bitmap. If the config is Bitmap.Config.RGBA_F16 , scRGB is assumed, and if the config is not Bitmap.Config.ARGB_8888 , sRGB is assumed. This value must never be |
Returns | |
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Bitmap |
Throws | |
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IllegalArgumentException |
if the width or height are <= 0, if Config is Config.HARDWARE (because hardware bitmaps are always immutable), if the specified color space is not RGB , if the specified color space's transfer function is not an ICC parametric curve , or if the color space is null |
createBitmap
added in API level 1
public static Bitmap createBitmap (Bitmap src)
Returns an immutable bitmap from the source bitmap. The new bitmap may be the same object as source, or a copy may have been made. It is initialized with the same density and color space as the original bitmap.
Parameters | |
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src |
Bitmap This value must never be |
Returns | |
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Bitmap |
createBitmap
added in API level 28
public static Bitmap createBitmap (Picture source)
Creates a Bitmap from the given Picture
source of recorded drawing commands. Equivalent to calling createBitmap(Picture, int, int, Config)
with width and height the same as the Picture's width and height and a Config.HARDWARE config.
Parameters | |
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source |
Picture : The recorded Picture of drawing commands that will be drawn into the returned Bitmap. This value must never be |
Returns | |
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Bitmap |
An immutable bitmap with a HARDWARE config whose contents are created from the recorded drawing commands in the Picture source. This value will never be |
createBitmap
added in API level 17
public static Bitmap createBitmap (DisplayMetrics display, int[] colors, int offset, int stride, int width, int height, Bitmap.Config config)
Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. Its initial density is determined from the given DisplayMetrics
. The newly created bitmap is in the sRGB
color space.
Parameters | |
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display |
DisplayMetrics : Display metrics for the display this bitmap will be drawn on. This value must never be |
colors |
int : Array of sRGB colors used to initialize the pixels. This value must never be |
offset |
int : Number of values to skip before the first color in the array of colors. |
stride |
int : Number of colors in the array between rows (must be >= width or <= -width). |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. If the config does not support per-pixel alpha (e.g. RGB_565), then the alpha bytes in the colors[] will be ignored (assumed to be FF) This value must never be |
Returns | |
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Bitmap |
Throws | |
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IllegalArgumentException |
if the width or height are <= 0, or if the color array's length is less than the number of pixels. |
createBitmap
added in API level 17
public static Bitmap createBitmap (DisplayMetrics display, int[] colors, int width, int height, Bitmap.Config config)
Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. Its initial density is determined from the given DisplayMetrics
. The newly created bitmap is in the sRGB
color space.
Parameters | |
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display |
DisplayMetrics : Display metrics for the display this bitmap will be drawn on. This value may be |
colors |
int : Array of sRGB colors used to initialize the pixels. This array must be at least as large as width * height. This value must never be |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. If the config does not support per-pixel alpha (e.g. RGB_565), then the alpha bytes in the colors[] will be ignored (assumed to be FF) This value must never be |
Returns | |
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Bitmap |
Throws | |
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IllegalArgumentException |
if the width or height are <= 0, or if the color array's length is less than the number of pixels. |
createBitmap
added in API level 17
public static Bitmap createBitmap (DisplayMetrics display, int width, int height, Bitmap.Config config)
Returns a mutable bitmap with the specified width and height. Its initial density is determined from the given DisplayMetrics
. The newly created bitmap is in the sRGB
color space.
Parameters | |
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display |
DisplayMetrics : Display metrics for the display this bitmap will be drawn on. This value may be |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. This value must never be |
Returns | |
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Bitmap |
Throws | |
---|---|
IllegalArgumentException |
if the width or height are <= 0, or if Config is Config.HARDWARE, because hardware bitmaps are always immutable |
createBitmap
added in API level 1
public static Bitmap createBitmap (int[] colors, int offset, int stride, int width, int height, Bitmap.Config config)
Returns a immutable bitmap with the specified width and height, with each pixel value set to the corresponding value in the colors array. Its initial density is as per getDensity()
. The newly created bitmap is in the sRGB
color space.
Parameters | |
---|---|
colors |
int : Array of sRGB colors used to initialize the pixels. This value must never be |
offset |
int : Number of values to skip before the first color in the array of colors. |
stride |
int : Number of colors in the array between rows (must be >= width or <= -width). |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. If the config does not support per-pixel alpha (e.g. RGB_565), then the alpha bytes in the colors[] will be ignored (assumed to be FF) This value must never be |
Returns | |
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Bitmap |
Throws | |
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IllegalArgumentException |
if the width or height are <= 0, or if the color array's length is less than the number of pixels. |
createBitmap
added in API level 28
public static Bitmap createBitmap (Picture source, int width, int height, Bitmap.Config config)
Creates a Bitmap from the given Picture
source of recorded drawing commands. The bitmap will be immutable with the given width and height. If the width and height are not the same as the Picture's width & height, the Picture will be scaled to fit the given width and height.
Parameters | |
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source |
Picture : The recorded Picture of drawing commands that will be drawn into the returned Bitmap. This value must never be |
width |
int : The width of the bitmap to create. The picture's width will be scaled to match if necessary. |
height |
int : The height of the bitmap to create. The picture's height will be scaled to match if necessary. |
config |
Bitmap.Config : The Bitmap.Config of the created bitmap. If this is null then the bitmap will be Bitmap.Config.HARDWARE . |
Returns | |
---|---|
Bitmap |
An immutable bitmap with a HARDWARE config whose contents are created from the recorded drawing commands in the Picture source. This value will never be |
createBitmap
added in API level 26
public static Bitmap createBitmap (int width, int height, Bitmap.Config config, boolean hasAlpha, ColorSpace colorSpace)
Returns a mutable bitmap with the specified width and height. Its initial density is as per getDensity()
.
Parameters | |
---|---|
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. This value must never be |
hasAlpha |
boolean : If the bitmap is ARGB_8888 or RGBA_16F this flag can be used to mark the bitmap as opaque. Doing so will clear the bitmap in black instead of transparent. |
colorSpace |
ColorSpace : The color space of the bitmap. If the config is Bitmap.Config.RGBA_F16 , scRGB is assumed, and if the config is not Bitmap.Config.ARGB_8888 , sRGB is assumed. This value must never be |
Returns | |
---|---|
Bitmap |
Throws | |
---|---|
IllegalArgumentException |
if the width or height are <= 0, if Config is Config.HARDWARE (because hardware bitmaps are always immutable), if the specified color space is not RGB , if the specified color space's transfer function is not an ICC parametric curve , or if the color space is null |
createBitmap
added in API level 26
public static Bitmap createBitmap (DisplayMetrics display, int width, int height, Bitmap.Config config, boolean hasAlpha)
Returns a mutable bitmap with the specified width and height. Its initial density is determined from the given DisplayMetrics
. The newly created bitmap is in the sRGB
color space.
Parameters | |
---|---|
display |
DisplayMetrics : Display metrics for the display this bitmap will be drawn on. This value may be |
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. This value must never be |
hasAlpha |
boolean : If the bitmap is ARGB_8888 or RGBA_16F this flag can be used to mark the bitmap as opaque. Doing so will clear the bitmap in black instead of transparent. |
Returns | |
---|---|
Bitmap |
Throws | |
---|---|
IllegalArgumentException |
if the width or height are <= 0, or if Config is Config.HARDWARE, because hardware bitmaps are always immutable |
createBitmap
added in API level 1
public static Bitmap createBitmap (int width, int height, Bitmap.Config config)
Returns a mutable bitmap with the specified width and height. Its initial density is as per getDensity()
. The newly created bitmap is in the sRGB
color space.
Parameters | |
---|---|
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. This value must never be |
Returns | |
---|---|
Bitmap |
Throws | |
---|---|
IllegalArgumentException |
if the width or height are <= 0, or if Config is Config.HARDWARE, because hardware bitmaps are always immutable |
createBitmap
added in API level 26
public static Bitmap createBitmap (int width, int height, Bitmap.Config config, boolean hasAlpha)
Returns a mutable bitmap with the specified width and height. Its initial density is as per getDensity()
. The newly created bitmap is in the sRGB
color space.
Parameters | |
---|---|
width |
int : The width of the bitmap |
height |
int : The height of the bitmap |
config |
Bitmap.Config : The bitmap config to create. This value must never be |
hasAlpha |
boolean : If the bitmap is ARGB_8888 or RGBA_16F this flag can be used to mark the bitmap as opaque. Doing so will clear the bitmap in black instead of transparent. |
Returns | |
---|---|
Bitmap |
Throws | |
---|---|
IllegalArgumentException |
if the width or height are <= 0, or if Config is Config.HARDWARE, because hardware bitmaps are always immutable |
createScaledBitmap
added in API level 1
public static Bitmap createScaledBitmap (Bitmap src, int dstWidth, int dstHeight, boolean filter)
Creates a new bitmap, scaled from an existing bitmap, when possible. If the specified width and height are the same as the current width and height of the source bitmap, the source bitmap is returned and no new bitmap is created.
Parameters | |
---|---|
src |
Bitmap : The source bitmap. This value must never be |
dstWidth |
int : The new bitmap's desired width. |
dstHeight |
int : The new bitmap's desired height. |
filter |
boolean : true if the source should be filtered. |
Returns | |
---|---|
Bitmap |
The new scaled bitmap or the source bitmap if no scaling is required. |
Throws | |
---|---|
IllegalArgumentException |
if width is <= 0, or height is <= 0 |
describeContents
added in API level 1
public int describeContents ()
No special parcel contents.
Returns | |
---|---|
int |
a bitmask indicating the set of special object types marshaled by this Parcelable object instance. |
eraseColor
added in API level 1
public void eraseColor (int c)
Fills the bitmap's pixels with the specified Color
.
Parameters | |
---|---|
c |
int |
Throws | |
---|---|
IllegalStateException |
if the bitmap is not mutable. |
extractAlpha
added in API level 1
public Bitmap extractAlpha ()
Returns a new bitmap that captures the alpha values of the original. This may be drawn with Canvas.drawBitmap(), where the color(s) will be taken from the paint that is passed to the draw call.
Returns | |
---|---|
Bitmap |
new bitmap containing the alpha channel of the original bitmap. |
extractAlpha
added in API level 1
public Bitmap extractAlpha (Paint paint, int[] offsetXY)
Returns a new bitmap that captures the alpha values of the original. These values may be affected by the optional Paint parameter, which can contain its own alpha, and may also contain a MaskFilter which could change the actual dimensions of the resulting bitmap (e.g. a blur maskfilter might enlarge the resulting bitmap). If offsetXY is not null, it returns the amount to offset the returned bitmap so that it will logically align with the original. For example, if the paint contains a blur of radius 2, then offsetXY[] would contains -2, -2, so that drawing the alpha bitmap offset by (-2, -2) and then drawing the original would result in the blur visually aligning with the original.
The initial density of the returned bitmap is the same as the original's.
Parameters | |
---|---|
paint |
Paint : Optional paint used to modify the alpha values in the resulting bitmap. Pass null for default behavior. |
offsetXY |
int : Optional array that returns the X (index 0) and Y (index 1) offset needed to position the returned bitmap so that it visually lines up with the original. |
Returns | |
---|---|
Bitmap |
new bitmap containing the (optionally modified by paint) alpha channel of the original bitmap. This may be drawn with Canvas.drawBitmap(), where the color(s) will be taken from the paint that is passed to the draw call. |
getAllocationByteCount
added in API level 19
public int getAllocationByteCount ()
Returns the size of the allocated memory used to store this bitmap's pixels.
This can be larger than the result of getByteCount()
if a bitmap is reused to decode other bitmaps of smaller size, or by manual reconfiguration. See reconfigure(int, int, Config)
, setWidth(int)
, setHeight(int)
, setConfig(Bitmap.Config)
, and BitmapFactory.Options.inBitmap
. If a bitmap is not modified in this way, this value will be the same as that returned by getByteCount()
.
This value will not change over the lifetime of a Bitmap.
Returns | |
---|---|
int |
See also:
getByteCount
added in API level 12
public int getByteCount ()
Returns the minimum number of bytes that can be used to store this bitmap's pixels.
As of Build.VERSION_CODES.KITKAT
, the result of this method can no longer be used to determine memory usage of a bitmap. See getAllocationByteCount()
.
Returns | |
---|---|
int |
getColorSpace
added in API level 26
public ColorSpace getColorSpace ()
Returns the color space associated with this bitmap. If the color space is unknown, this method returns null.
Returns | |
---|---|
ColorSpace |
This value may be |
getConfig
added in API level 1
public Bitmap.Config getConfig ()
If the bitmap's internal config is in one of the public formats, return that config, otherwise return null.
Returns | |
---|---|
Bitmap.Config |
getDensity
added in API level 4
public int getDensity ()
Returns the density for this bitmap.
The default density is the same density as the current display, unless the current application does not support different screen densities in which case it is DisplayMetrics.DENSITY_DEFAULT
. Note that compatibility mode is determined by the application that was initially loaded into a process -- applications that share the same process should all have the same compatibility, or ensure they explicitly set the density of their bitmaps appropriately.
Returns | |
---|---|
int |
A scaling factor of the default density or DENSITY_NONE if the scaling factor is unknown. |
See also:
getGenerationId
added in API level 12
public int getGenerationId ()
Returns the generation ID of this bitmap. The generation ID changes whenever the bitmap is modified. This can be used as an efficient way to check if a bitmap has changed.
Returns | |
---|---|
int |
The current generation ID for this bitmap. |
getHeight
added in API level 1
public int getHeight ()
Returns the bitmap's height
Returns | |
---|---|
int |
getNinePatchChunk
added in API level 1
public byte[] getNinePatchChunk ()
Returns an optional array of private data, used by the UI system for some bitmaps. Not intended to be called by applications.
Returns | |
---|---|
byte[] |
getPixel
added in API level 1
public int getPixel (int x, int y)
Returns the Color
at the specified location. Throws an exception if x or y are out of bounds (negative or >= to the width or height respectively). The returned color is a non-premultiplied ARGB value in the sRGB
color space.
Parameters | |
---|---|
x |
int : The x coordinate (0...width-1) of the pixel to return |
y |
int : The y coordinate (0...height-1) of the pixel to return |
Returns | |
---|---|
int |
The argb Color at the specified coordinate |
Throws | |
---|---|
IllegalArgumentException |
if x, y exceed the bitmap's bounds |
IllegalStateException |
if the bitmap's config is Bitmap.Config.HARDWARE |
getPixels
added in API level 1
public void getPixels (int[] pixels, int offset, int stride, int x, int y, int width, int height)
Returns in pixels[] a copy of the data in the bitmap. Each value is a packed int representing a Color
. The stride parameter allows the caller to allow for gaps in the returned pixels array between rows. For normal packed results, just pass width for the stride value. The returned colors are non-premultiplied ARGB values in the sRGB
color space.
Parameters | |
---|---|
pixels |
int : The array to receive the bitmap's colors |
offset |
int : The first index to write into pixels[] |
stride |
int : The number of entries in pixels[] to skip between rows (must be >= bitmap's width). Can be negative. |
x |
int : The x coordinate of the first pixel to read from the bitmap |
y |
int : The y coordinate of the first pixel to read from the bitmap |
width |
int : The number of pixels to read from each row |
height |
int : The number of rows to read |
Throws | |
---|---|
IllegalArgumentException |
if x, y, width, height exceed the bounds of the bitmap, or if abs(stride) < width. |
ArrayIndexOutOfBoundsException |
if the pixels array is too small to receive the specified number of pixels. |
IllegalStateException |
if the bitmap's config is Bitmap.Config.HARDWARE |
getRowBytes
added in API level 1
public int getRowBytes ()
Return the number of bytes between rows in the bitmap's pixels. Note that this refers to the pixels as stored natively by the bitmap. If you call getPixels() or setPixels(), then the pixels are uniformly treated as 32bit values, packed according to the Color class.
As of Build.VERSION_CODES.KITKAT
, this method should not be used to calculate the memory usage of the bitmap. Instead, see getAllocationByteCount()
.
Returns | |
---|---|
int |
number of bytes between rows of the native bitmap pixels. |
getScaledHeight
added in API level 4
public int getScaledHeight (int targetDensity)
Convenience method that returns the height of this bitmap divided by the density scale factor.
Parameters | |
---|---|
targetDensity |
int : The density of the target canvas of the bitmap. |
Returns | |
---|---|
int |
The scaled height of this bitmap, according to the density scale factor. |
getScaledHeight
added in API level 4
public int getScaledHeight (Canvas canvas)
Convenience for calling getScaledHeight(int)
with the target density of the given Canvas
.
Parameters | |
---|---|
canvas |
Canvas |
Returns | |
---|---|
int |
getScaledHeight
added in API level 4
public int getScaledHeight (DisplayMetrics metrics)
Convenience for calling getScaledHeight(int)
with the target density of the given DisplayMetrics
.
Parameters | |
---|---|
metrics |
DisplayMetrics |
Returns | |
---|---|
int |
getScaledWidth
added in API level 4
public int getScaledWidth (int targetDensity)
Convenience method that returns the width of this bitmap divided by the density scale factor.
Parameters | |
---|---|
targetDensity |
int : The density of the target canvas of the bitmap. |
Returns | |
---|---|
int |
The scaled width of this bitmap, according to the density scale factor. |
getScaledWidth
added in API level 4
public int getScaledWidth (DisplayMetrics metrics)
Convenience for calling getScaledWidth(int)
with the target density of the given DisplayMetrics
.
Parameters | |
---|---|
metrics |
DisplayMetrics |
Returns | |
---|---|
int |
getScaledWidth
added in API level 4
public int getScaledWidth (Canvas canvas)
Convenience for calling getScaledWidth(int)
with the target density of the given Canvas
.
Parameters | |
---|---|
canvas |
Canvas |
Returns | |
---|---|
int |
getWidth
added in API level 1
public int getWidth ()
Returns the bitmap's width
Returns | |
---|---|
int |
hasAlpha
added in API level 1
public boolean hasAlpha ()
Returns true if the bitmap's config supports per-pixel alpha, and if the pixels may contain non-opaque alpha values. For some configs, this is always false (e.g. RGB_565), since they do not support per-pixel alpha. However, for configs that do, the bitmap may be flagged to be known that all of its pixels are opaque. In this case hasAlpha() will also return false. If a config such as ARGB_8888 is not so flagged, it will return true by default.
Returns | |
---|---|
boolean |
hasMipMap
added in API level 17
public boolean hasMipMap ()
Indicates whether the renderer responsible for drawing this bitmap should attempt to use mipmaps when this bitmap is drawn scaled down. If you know that you are going to draw this bitmap at less than 50% of its original size, you may be able to obtain a higher quality This property is only a suggestion that can be ignored by the renderer. It is not guaranteed to have any effect.
Returns | |
---|---|
boolean |
true if the renderer should attempt to use mipmaps, false otherwise |
See also:
isMutable
added in API level 1
public boolean isMutable ()
Returns true if the bitmap is marked as mutable (i.e. can be drawn into)
Returns | |
---|---|
boolean |
isPremultiplied
added in API level 17
public boolean isPremultiplied ()
Indicates whether pixels stored in this bitmaps are stored pre-multiplied. When a pixel is pre-multiplied, the RGB components have been multiplied by the alpha component. For instance, if the original color is a 50% translucent red (128, 255, 0, 0)
, the pre-multiplied form is (128, 128, 0, 0)
.
This method always returns false if getConfig()
is Bitmap.Config.RGB_565
.
The return value is undefined if getConfig()
is Bitmap.Config.ALPHA_8
.
This method only returns true if hasAlpha()
returns true. A bitmap with no alpha channel can be used both as a pre-multiplied and as a non pre-multiplied bitmap.
Only pre-multiplied bitmaps may be drawn by the view system or Canvas
. If a non-pre-multiplied bitmap with an alpha channel is drawn to a Canvas, a RuntimeException will be thrown.
Returns | |
---|---|
boolean |
true if the underlying pixels have been pre-multiplied, false otherwise |
See also:
isRecycled
added in API level 1
public boolean isRecycled ()
Returns true if this bitmap has been recycled. If so, then it is an error to try to access its pixels, and the bitmap will not draw.
Returns | |
---|---|
boolean |
true if the bitmap has been recycled |
prepareToDraw
added in API level 4
public void prepareToDraw ()
Builds caches associated with the bitmap that are used for drawing it.
Starting in Build.VERSION_CODES.N
, this call initiates an asynchronous upload to the GPU on RenderThread, if the Bitmap is not already uploaded. With Hardware Acceleration, Bitmaps must be uploaded to the GPU in order to be rendered. This is done by default the first time a Bitmap is drawn, but the process can take several milliseconds, depending on the size of the Bitmap. Each time a Bitmap is modified and drawn again, it must be re-uploaded.
Calling this method in advance can save time in the first frame it's used. For example, it is recommended to call this on an image decoding worker thread when a decoded Bitmap is about to be displayed. It is recommended to make any pre-draw modifications to the Bitmap before calling this method, so the cached, uploaded copy may be reused without re-uploading.
In Build.VERSION_CODES.KITKAT
and below, for purgeable bitmaps, this call would attempt to ensure that the pixels have been decoded.
reconfigure
added in API level 19
public void reconfigure (int width, int height, Bitmap.Config config)
Modifies the bitmap to have a specified width, height, and Bitmap.Config
, without affecting the underlying allocation backing the bitmap. Bitmap pixel data is not re-initialized for the new configuration.
This method can be used to avoid allocating a new bitmap, instead reusing an existing bitmap's allocation for a new configuration of equal or lesser size. If the Bitmap's allocation isn't large enough to support the new configuration, an IllegalArgumentException will be thrown and the bitmap will not be modified.
The result of getByteCount()
will reflect the new configuration, while getAllocationByteCount()
will reflect that of the initial configuration.
Note: This may change this result of hasAlpha(). When converting to 565, the new bitmap will always be considered opaque. When converting from 565, the new bitmap will be considered non-opaque, and will respect the value set by setPremultiplied().
WARNING: This method should NOT be called on a bitmap currently in use by the view system, Canvas, or the AndroidBitmap NDK API. It does not make guarantees about how the underlying pixel buffer is remapped to the new config, just that the allocation is reused. Additionally, the view system does not account for bitmap properties being modifying during use, e.g. while attached to drawables.
In order to safely ensure that a Bitmap is no longer in use by the View system it is necessary to wait for a draw pass to occur after invalidate()'ing any view that had previously drawn the Bitmap in the last draw pass due to hardware acceleration's caching of draw commands. As an example, here is how this can be done for an ImageView:
ImageView myImageView = ...;
final Bitmap myBitmap = ...;
myImageView.setImageDrawable(null);
myImageView.post(new Runnable() {
public void run() {
// myBitmap is now no longer in use by the ImageView
// and can be safely reconfigured.
myBitmap.reconfigure(...);
}
});
Parameters | |
---|---|
width |
int |
height |
int |
config |
Bitmap.Config |
See also:
recycle
added in API level 1
public void recycle ()
Free the native object associated with this bitmap, and clear the reference to the pixel data. This will not free the pixel data synchronously; it simply allows it to be garbage collected if there are no other references. The bitmap is marked as "dead", meaning it will throw an exception if getPixels() or setPixels() is called, and will draw nothing. This operation cannot be reversed, so it should only be called if you are sure there are no further uses for the bitmap. This is an advanced call, and normally need not be called, since the normal GC process will free up this memory when there are no more references to this bitmap.
sameAs
added in API level 12
public boolean sameAs (Bitmap other)
Given another bitmap, return true if it has the same dimensions, config, and pixel data as this bitmap. If any of those differ, return false. If other is null, return false.
Parameters | |
---|---|
other |
Bitmap |
Returns | |
---|---|
boolean |
setConfig
added in API level 19
public void setConfig (Bitmap.Config config)
Convenience method for calling reconfigure(int, int, Config)
with the current height and width.
WARNING: this method should not be used on bitmaps currently used by the view system, see reconfigure(int, int, Config)
for more details.
Parameters | |
---|---|
config |
Bitmap.Config |
See also:
setDensity
added in API level 4
public void setDensity (int density)
Specifies the density for this bitmap. When the bitmap is drawn to a Canvas that also has a density, it will be scaled appropriately.
Parameters | |
---|---|
density |
int : The density scaling factor to use with this bitmap or DENSITY_NONE if the density is unknown. |
See also:
setHasAlpha
added in API level 12
public void setHasAlpha (boolean hasAlpha)
Tell the bitmap if all of the pixels are known to be opaque (false) or if some of the pixels may contain non-opaque alpha values (true). Note, for some configs (e.g. RGB_565) this call is ignored, since it does not support per-pixel alpha values. This is meant as a drawing hint, as in some cases a bitmap that is known to be opaque can take a faster drawing case than one that may have non-opaque per-pixel alpha values.
Parameters | |
---|---|
hasAlpha |
boolean |
setHasMipMap
added in API level 17
public void setHasMipMap (boolean hasMipMap)
Set a hint for the renderer responsible for drawing this bitmap indicating that it should attempt to use mipmaps when this bitmap is drawn scaled down. If you know that you are going to draw this bitmap at less than 50% of its original size, you may be able to obtain a higher quality by turning this property on. Note that if the renderer respects this hint it might have to allocate extra memory to hold the mipmap levels for this bitmap. This property is only a suggestion that can be ignored by the renderer. It is not guaranteed to have any effect.
Parameters | |
---|---|
hasMipMap |
boolean : indicates whether the renderer should attempt to use mipmaps |
See also:
setHeight
added in API level 19
public void setHeight (int height)
Convenience method for calling reconfigure(int, int, Config)
with the current width and config.
WARNING: this method should not be used on bitmaps currently used by the view system, see reconfigure(int, int, Config)
for more details.
Parameters | |
---|---|
height |
int |
See also:
setPixel
added in API level 1
public void setPixel (int x, int y, int color)
Write the specified Color
into the bitmap (assuming it is mutable) at the x,y coordinate. The color must be a non-premultiplied ARGB value in the sRGB
color space.
Parameters | |
---|---|
x |
int : The x coordinate of the pixel to replace (0...width-1) |
y |
int : The y coordinate of the pixel to replace (0...height-1) |
color |
int : The ARGB color to write into the bitmap |
Throws | |
---|---|
IllegalStateException |
if the bitmap is not mutable |
IllegalArgumentException |
if x, y are outside of the bitmap's bounds. |
setPixels
added in API level 1
public void setPixels (int[] pixels, int offset, int stride, int x, int y, int width, int height)
Replace pixels in the bitmap with the colors in the array. Each element in the array is a packed int representing a non-premultiplied ARGB Color
in the sRGB
color space.
Parameters | |
---|---|
pixels |
int : The colors to write to the bitmap |
offset |
int : The index of the first color to read from pixels[] |
stride |
int : The number of colors in pixels[] to skip between rows. Normally this value will be the same as the width of the bitmap, but it can be larger (or negative). |
x |
int : The x coordinate of the first pixel to write to in the bitmap. |
y |
int : The y coordinate of the first pixel to write to in the bitmap. |
width |
int : The number of colors to copy from pixels[] per row |
height |
int : The number of rows to write to the bitmap |
Throws | |
---|---|
IllegalStateException |
if the bitmap is not mutable |
IllegalArgumentException |
if x, y, width, height are outside of the bitmap's bounds. |
ArrayIndexOutOfBoundsException |
if the pixels array is too small to receive the specified number of pixels. |
setPremultiplied
added in API level 19
public void setPremultiplied (boolean premultiplied)
Sets whether the bitmap should treat its data as pre-multiplied.
Bitmaps are always treated as pre-multiplied by the view system and Canvas
for performance reasons. Storing un-pre-multiplied data in a Bitmap (through setPixel(int, int, int)
, setPixels(int[], int, int, int, int, int, int)
, or BitmapFactory.Options.inPremultiplied
) can lead to incorrect blending if drawn by the framework.
This method will not affect the behavior of a bitmap without an alpha channel, or if hasAlpha()
returns false.
Calling createBitmap(Bitmap)
or createScaledBitmap(Bitmap, int, int, boolean)
with a source Bitmap whose colors are not pre-multiplied may result in a RuntimeException, since those functions require drawing the source, which is not supported for un-pre-multiplied Bitmaps.
Parameters | |
---|---|
premultiplied |
boolean |
See also:
setWidth
added in API level 19
public void setWidth (int width)
Convenience method for calling reconfigure(int, int, Config)
with the current height and config.
WARNING: this method should not be used on bitmaps currently used by the view system, see reconfigure(int, int, Config)
for more details.
Parameters | |
---|---|
width |
int |
See also:
writeToParcel
added in API level 1
public void writeToParcel (Parcel p, int flags)
Write the bitmap and its pixels to the parcel. The bitmap can be rebuilt from the parcel by calling CREATOR.createFromParcel(). If this bitmap is Bitmap.Config.HARDWARE
, it may be unparceled with a different pixel format (e.g. 565, 8888), but the content will be preserved to the best quality permitted by the final pixel format
Parameters | |
---|---|
p |
Parcel : Parcel object to write the bitmap data into |
flags |
int : Additional flags about how the object should be written. May be 0 or Parcelable.PARCELABLE_WRITE_RETURN_VALUE . |