直接上代码
#include <opencv2/opencv.hpp>
#include <stdio.h>
#define min(a,b) ((a<b)?a:b)
#define max(a,b) ((a>b)?a:b)
/************************************************************************/
/* YUV12 to RGB24 (4) Basic Optimizations 3.1 */
/************************************************************************/
int yuv420_to_argb888(const unsigned char *y, const unsigned char *u,const unsigned char *v ,int width ,int height ,unsigned char *rgb)
{
static const int Precision = 32768 ;
static const int Coefficient_y = (int) (1.164*Precision + 0.5);
static const int Coefficient_rv = (int) (1.596*Precision + 0.5);
static const int Coefficient_gu = (int) (0.391*Precision + 0.5);
static const int Coefficient_gv = (int) (0.813*Precision + 0.5);
static const int Coefficient_bu = (int) (2.018*Precision + 0.5);
static int CoefficientY[256];
static int CoefficientRV[256];
static int CoefficientGU[256];
static int CoefficientGV[256];
static int CoefficientBU[256];
static int _CoefficientsR[1024];
//static int _CoefficientsG[1024];
//static int _CoefficientsB[1024];
static int flag = 1 ;
if (flag)
{
for(int i =0;i<256;i++)
{
CoefficientY[i] = Coefficient_y *(i - 16) + (Precision/2);
CoefficientGV[i] = -Coefficient_gv *(i - 128);
CoefficientBU[i] = Coefficient_bu *(i - 128);
CoefficientGU[i] = -Coefficient_gu *(i - 128);
CoefficientRV[i] = Coefficient_rv *(i - 128);
}
for(int j=0;j<1024;j++)
{
_CoefficientsR[j] = min((max(j-320,0)),255) ;
//_CoefficientsG[j] = min((max(j-320,0)),255) ;
//_CoefficientsB[j] = min((max(j-320,0)),255) ;
}
flag = 0;
}
CoefficientY[0] = -593888;
CoefficientY[1] = -555746; //修复bug!! CoefficientY[1]在第二次进入此函数的时候意外被改动为非常大的数,理论值应该为-555746
int *CoefficientsR = &_CoefficientsR[320];
// int *CoefficientsG = &_CoefficientsG[320];
// int *CoefficientsB = &_CoefficientsB[320];
for ( int h=0;h<height;h++)
{
for (int w=0;w<width;w++)
{
int k = h*width + w;
int index = k*3;
int i = (h/2)*(width/2)+(w/2);
int Y = y[k];
int U = u[i];
int V = v[i];
//3.3 Optimizations Removing Conditional Tests
int r = CoefficientY[Y] + CoefficientRV[V];
int g = CoefficientY[Y] + CoefficientGU[U]+ CoefficientGV[V];
int b = CoefficientY[Y] + CoefficientBU[U];
rgb[index] = CoefficientsR[r/Precision];
rgb[index+1] = CoefficientsR[g/Precision];
rgb[index+2] = CoefficientsR[b/Precision];
}
}
return 0;
}
//Compare 3 images histograms together,
// the first is divided in half along y to test its other half
// Call is:
// ch7HistCmp modelImage0 testImage1 testImage2 badImage3
// Note that the model image is split in half. Top half(0) makes model. It's then tested
// against its lower half(0), testImages 1 and 2 in different lighting and different object 3
//
int main( int argc, char** argv ) {
IplImage* src[5], *tmp;
int i;
if((src[0] = cvLoadImage(argv[1], 1)) == 0){ //We're going to split this one in half
printf("Error on reading image 1, %s
",argv[1]);
return(-1);
}
//Parse the first image into two image halves divided halfway on y
printf("Getting size [[%d] [%d]] format is [%s]
",src[0]->width,src[0]->height,src[0]->channelSeq);
CvSize size = cvGetSize(src[0]);
printf("Get size %d %d
",size.width,size.height);
int width = size.width;
int height = size.height;
int halfheight = height >> 1;
//RGB888 to YUV420
unsigned char * rgb = (unsigned char*)src[0]->imageData;
unsigned char * yuv = (unsigned char*)malloc(width*height + width*height/2);
unsigned char * y = yuv;
unsigned char * u = &yuv[width*height];
unsigned char * v = &yuv[width*height+width*height/4];
int k = 0;
for(int i = 0;i<height ;i++)
{
for(int j =0;j<width;j++)
{
int index = i*width+j;
unsigned char R = rgb[width*i*3+j*3];
unsigned char G = rgb[width*i*3+j*3+1];
unsigned char B = rgb[width*i*3+j*3+2];
y[index] = ( ( 66 * R + 129 * G + 25 * B + 128) >> 8) + 16;
y[index] = min(max(y[index],0),255);
if( (j%2 ==0)&&(i%2 == 0) )
{
k++;
u[k] = ( ( -38 * R - 74 * G + 112 * B + 128) >> 8) + 128;
v[k] = ( ( 112 * R - 94 * G - 18 * B + 128) >> 8) + 128;
u[k] = min(max(u[k],0),255);
v[k] = min(max(v[k],0),255);
}
}
}
src[1] = cvCreateImage(cvSize(width,height), 8, 3);
yuv420_to_argb888((const unsigned char*)y,(const unsigned char*)u,(const unsigned char*)v,width,height,(unsigned char *)src[1]->imageData);
//DISPLAY
cvNamedWindow( "Source0", 1 );
cvShowImage( "Source0", src[0] );//原图RGB
cvNamedWindow( "Source1", 1 );
cvShowImage( "Source1", src[1] );//经过RGB88->YUV420->RGB888后的图像
cvWaitKey(0);
free(yuv) }