packagecom.demo;
importjavax.imageio.ImageIO;
importjava.awt.image.BufferedImage;
importjava.io.File;
importjava.io.IOException;
import staticcom.demo.MyColorUtil.decodeYUV420SP;
/**
* Created by ff135 on 2017/4/27.
* RGB转YUV:
Y = 0.299 R + 0.587 G + 0.114 B
U = - 0.1687 R - 0.3313 G + 0.5 B + 128
V = 0.5 R - 0.4187 G - 0.0813 B + 128
YUV转RGB
R = Y + 1.402 (V - 128)
G = Y - 0.34414 (U - 128) - 0.71414 (V - 128)
B = Y + 1.772 (U - 128)
*
*
*
*/
public classTestUtil {
public static voidmain(String[] args) {
File imgFile =newFile("E:/p3.jpg");
try{
BufferedImage bufferedImage = ImageIO.read(imgFile);
intwidth = bufferedImage.getWidth();
intheight = bufferedImage.getHeight();
int[] pixels = bufferedImage.getRGB(0,0,width,height,null,0,width);
byte[] yuvs=encodeYUV420SP(pixels,width,height);
int[] pixelsNew=decodeYUV420sp(yuvs,width,height);
BufferedImage newbuff=newBufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
newbuff.setRGB(0,0,width,height,pixelsNew,0,width);
ImageIO.write(newbuff,"jpg",newFile("E:/yy.jpg"));
}catch(IOException e) {
e.printStackTrace();
}
}
/**
* nv21 先u后v
*
*@paramargb
*@paramwidth
*@paramheight
*@return
*/
public static byte[] encodeYUV420SP(int[] argb,intwidth,intheight){
intsize = (int) ((Math.ceil(width/2.0)) * (Math.ceil(height/2.0)));
intframeSize = width * height;
byte[] yuvs=new byte[frameSize + size *2];
inty=0,u=0,v=0;
intr=0,g=0,b=0,a=0;
intindex=0,uvindex=frameSize;
for(inti =0; i < height; i++) {
for(intj =0; j < width; j++) {
a = (argb[index] &0xff000000) >>24;// a is not used obviously
r = (argb[index] &0xff0000) >>16;
g = (argb[index] &0xff00) >>8;
b = (argb[index] &0xff) >>0;
//转换公式
y= (int) (0.299*r +0.587*g +0.114*b);
u= (int) (-0.1687*r -0.3313*g +0.5*b +128);
v= (int) (0.5*r -0.4187*g -0.0813*b +128);
System.out.println("x:"+i+"y:"+j+" y:"+y+" u:"+u+" v:"+v);
yuvs[index++] = (byte) ((y <0) ?0: ((y >255) ?255: y));
if(i%2==0&& j %2==0){
yuvs[uvindex++] = (byte) ((u <0) ?0: ((u >255) ?255: u));
yuvs[uvindex++] = (byte) ((v <0) ?0: ((v >255) ?255: v));
// yuvs[uvindex++]=(byte)120;
// yuvs[uvindex++] = (byte) ((v < 0) ? 0 : ((v > 255) ? 255 : v));
// yuvs[uvindex++]=(byte)240;
}
}
}
returnyuvs;
}
public static int[] decodeYUV420sp(byte[] yuvs ,intwidth,intheight){
intframeSize = width * height;
int[] rgbs =new int[frameSize];
intindex=0;
intuvindex=frameSize;
intu=0,v=0,y=0;
for(inti =0; i < height; i++) {
for(intj =0; j < width; j++) {
if(i%2==0&& j %2==0){
u=yuvs[uvindex++];
v=yuvs[uvindex++];
}
//保存到数组中去
y=yuvs[index];
rgbs[index++]=yuv2Rgb(y,u,v);
}
}
returnrgbs;
}
public static intyuv2Rgb(inty,intu,intv){
// 转换公式
intr = (int) ((y&0xff)+1.402*((v&0xff) -128));
intg = (int) ((y&0xff)-0.34414* ((u&0xff) -128) -0.71414* ((v&0xff) -128));
intb = (int) ((y&0xff)+1.772* ((u&0xff) -128));
r=(r<0?0:r>255?255:r);
g=(g<0?0:g>255?255:g);
b=(b<0?0:b>255?255:b);
return(0xff<<24) + (r<<16) + (g<<8) + b;
}
}
