/**
* convert bitmap to base64
*
* @param bitmap
* @return
*/
public static String bitmapToBase64(Bitmap bitmap) {
String result = null;
ByteArrayOutputStream baos = null;
try {
if (bitmap != null) {
baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);
baos.flush();
baos.close();
byte[] bitmapBytes = baos.toByteArray();
result = Base64.encodeToString(bitmapBytes, Base64.DEFAULT);
}
} catch (IOException e) {
e.printStackTrace ();
} finally {
try {
if (baos != null) {
baos.flush();
baos.close();
}
} catch (IOException e) {
e.printStackTrace ();
}
}
return result;
}
private Bitmap comp(Bitmap image) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
image.compress(Bitmap.CompressFormat.JPEG, 100, baos);
if( baos.toByteArray().length / 1024>1024) {//Judging that if the image is larger than 1M, compress it to avoid overflow when generating the image (BitmapFactory.decodeStream)
baos.reset();//Reset baos to clear baos
image.compress(Bitmap.CompressFormat.JPEG, 50, baos);//Compress 50% here, and store the compressed data in baos
}
ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());
BitmapFactory.Options newOpts = new BitmapFactory.Options();
//Start to read the picture, set options.inJustDecodeBounds back to true at this time
newOpts.inJustDecodeBounds = true;
Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, newOpts);
newOpts.inJustDecodeBounds = false;
int w = newOpts.outWidth;
int h = newOpts.outHeight;
//Now mainstream mobile phones are mostly 800*480 resolution, so we set the height and width to
float hh = 800f;//Here the height is set to 800f
float ww = 480f;//The width is set to 480f here
// Zoom ratio. Since it is a fixed scale scaling, only one data of height or width can be used for calculation.
int be = 1;//be=1 means no scaling
if (w > h && w > ww) {//If the width is large, it will be scaled according to the fixed size of the width
be = (int) (newOpts.outWidth / ww);
} else if (w < h && h > hh) {//If the height is high, it is scaled according to the fixed size of the width
be = (int) (newOpts.outHeight / hh);
}
if (be <= 0)
be = 1;
newOpts.inSampleSize = be;//Set the zoom ratio
newOpts.inPreferredConfig = Config.RGB_565;//Reduce the picture from ARGB888 to RGB565
//Re-read the picture, note that options.inJustDecodeBounds has been set back to false at this time
isBm = new ByteArrayInputStream(baos.toByteArray());
bitmap = BitmapFactory.decodeStream(isBm, null, newOpts);
return compressImage(bitmap);//Compress the scale and then perform quality compression
}
private Bitmap compressImage(Bitmap image) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
image.compress(Bitmap.CompressFormat.JPEG, 100, baos);//Quality compression method, where 100 means no compression, store the compressed data in baos
int options = 100;
while ( baos.toByteArray().length / 1024>100) { //Loop to determine if the compressed image is larger than 100kb, and continue to compress
baos.reset();//Reset baos to clear baos
options -= 10;//Reduce by 10 each time
image.compress(Bitmap.CompressFormat.JPEG, options, baos);//compress options% here, and store the compressed data in baos
}
ByteArrayInputStream isBm = new ByteArrayInputStream(baos.toByteArray());//Store the compressed data baos in ByteArrayInputStream
Bitmap bitmap = BitmapFactory.decodeStream(isBm, null, null);//Generate ByteArrayInputStream data into pictures
return bitmap;
}