Mosaic processing of pictures
The principle is as follows:
image coding is actually a way of spatial filtering in image convolution operation, using a certain size of filter to operate on pixels within the mosaic range. Realization process: Divide the range of horse racing into multiple blocks according to the size of the filter, take the pixels in the filter range, find the average value, and then assign the average value to each pixel in the range, and then the filter slides to the next block .
package com.itinspur.demo;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* 图像马赛克原理及其实现
* @program: practice_masaike
* @author: csl
* @create: 2021-02-23 09:55
*/
public class MosaicFilter {
/**
* @author: csl
*对整个图片进行马赛克处理
*对整张图像打码。对整张图片打码也叫做像素格特效，我们只需要考虑滤波器大小即可。
* @param image 获取到的图片流对象
* @param length 设置的马赛克的大小
*/
public void imageMosaic(BufferedImage image,int length){
//从流对象中获取相应图片的信息
//得到图片的宽度
int width = image.getWidth();
//得到图片的高度
int height = image.getHeight();
int size = length * length;
int x= width / length;
int y=height / length;
for (int i=0;i<x;i++){
for(int j=0;j<y;j++){
int R=0,G=0,B=0;
for(int m=0; m<length; m++){
for(int n=0; n<length; n++){
//Coordinate坐标
int xCoordinate = i * length + m;
int yCoordinate = j * length + n;
/* 应为使用getRGB(i,j)获取的该点的颜色值是ARGB，
而在实际应用中使用的是RGB，所以需要将ARGB转化成RGB
*/
int Argb =image.getRGB(xCoordinate,yCoordinate);
//相应的位运算符计算
// ＆ 如果相对应位都是1，则结果为1，否则为0
R += (Argb >> 16) & 0xff;
G += (Argb >> 8) & 0xff;
B += Argb & 0xff;
}
}
R = R / size;
G = G / size;
B = B / size;
int RGB = (255 & 0xff) << 24 | (clamp(R) & 0xff) << 16 | (clamp(G) & 0xff) << 8 | (clamp(B) & 0xff);
for(int m = 0; m < length; m++) {
for(int n = 0; n < length; n++) {
int xCoordinate = i * length + m;
int yCoordinate = j * length + n;
image.setRGB(xCoordinate, yCoordinate, RGB);
}
}
}
}
}
/**
* @author: csl
* 进行图片的局部马赛克打码
*局部打码。局部打码需要先定义好打码起始位置，打码范围，马赛克大小。
* @param image
* @param xCoordinate 横坐标起始位置
* @param yCoordinate 纵坐标起始位置
* @param xLength x方向长度
* @param yLength y方向长度
* @param length 马赛克大小
*/
public void mosaic(BufferedImage image,int xCoordinate,int yCoordinate,int xLength,int yLength,int length) {
//逻辑运算符 ||
if ((xCoordinate + xLength) > image.getWidth() || (yCoordinate + yLength) > image.getHeight()) {
System.out.println("马赛克范围大于图像范围！");
return;
}
int size = length * length;
int x = xLength / length;
int y = yLength / length;
for(int m = 0; m < x; m++) {
for(int n = 0; n < y; n++) {
int R=0,G=0,B=0;
for(int i = 0; i < length; i++) {
for(int j = 0; j < length; j++) {
int x1 = xCoordinate + m * length + i;
int y1 = yCoordinate + n * length + j;
int rgb = image.getRGB(x1, y1);
R += (rgb >> 16) & 0xff;
G += (rgb >> 8) & 0xff;
B += rgb & 0xff;
}
}
R = R / size;
G = G / size;
B = B / size;
int RGB = (255 & 0xff) << 24 | (clamp(R) & 0xff) << 16 | (clamp(G) & 0xff) << 8 | (clamp(B) & 0xff);
for(int i = 0; i < length; i++) {
for(int j = 0; j < length; j++) {
int x1 = xCoordinate + m * length + i;
int y1 = yCoordinate + n * length + j;
image.setRGB(x1, y1, RGB);
}
}
}
}
}
/**
* @author: csl
* 判断r,g,b值，大于256返回256，小于0则返回0,0到256之间则直接返回原始值
* 注意此if语句的写法
* @param Argb
* @return
*/
private int clamp(int Argb){
if(Argb > 255)
return 255;
if(Argb < 0)
return 0;
return Argb;
}
public static void main(String[] args) throws IOException {
File in = new File("E:/IMG_20180908_181626.jpg");
File out = new File("E:/IMG_20180908_181626-副本1.jpg");
BufferedImage image = ImageIO.read(in);
new MosaicFilter().imageMosaic(image, 100);
//new MosaicFilter().mosaic(image, 500, 100, 1000, 1700,100);
ImageIO.write(image, "jpg", out);
}
}
Original image without coding,
global coding
of the image, partial coding of the image
Note * @author: The
origin ofcslcoordinates is on the upper left, X to the right, Y to the bottom