Data compression (5)-color space conversion (full version) (2024)

experiment one:

• Write RGB to YUV program, focus on function definition, initialization and calling of some lookup tables, buffer allocation. Convert the obtained RGB file to YUV file and watch it with YUV Viewer player to verify whether it is correct.

• Write a program to convert YUV to RGB. Use this program to convert the given experimental data into RGB files. And with the original

  RGB files are compared, and if there are errors, analyze where the errors come from.

  I wrote a simple version before$4：4：4$4：4：4of$RGB$RGBFile and$4:4:4$4:4:4of$YUV$YUVFor file conversion, the link is as follows. This version of the article derives the conversion formula and the realization of sampling based on the previous article. If you only focus on two types of conversion, you can go directly to the non-sampling version to view the code and ideas.

Data compression (four)-color space conversion (non-sampling version)

$\begin{aligned} &R=(298\times Y+411\times V-57376)>>8\\ &G=(298\times Y-101\times U-211\times V+35168)>>8\\ &B=(298\times Y+519\times U-71200)>>8\\ &Y=(66\times R+129\times G+25\times B)>>8+16\\ &U=(-38\times R-74\times G+112\times B)>>8+128\\ &V=(112\times R-94\times G-18\times B)>>8+128 \end{aligned}$​R=(298×Y+411×V−57376)>>8G=(298×Y−101×U−211×V+35168)>>8B=(298×Y+519×U−71200)>>8Y=(66×R+129×G+25×B)>>8+16U=(−38×R−74×G+112×B)>>8+128V=(112×R−94×G−18×B)>>8+128​

  The above formula is already quantified.

1.1 Derivation of conversion formula

1.1.1 Conversion formula of analog signal

  According to the knowledge of TV principles, we can know the following formula:
$\begin{aligned} &Y=0.2990\times R+0.5870\times G+0.1140\times B\\ &U=B-Y=-0.2990\times R-0.5870\times G+0.8860\times B\\ &V=R-Y=0.7010\times R-0.5870\times G-0.1140\times B \end{aligned}$​Y=0.2990×R+0.5870×G+0.1140×BU=B−Y=−0.2990×R−0.5870×G+0.8860×BV=R−Y=0.7010×R−0.5870×G−0.1140×B​

1.1.2 Conversion formula of digital signal

Normalized

  In order to facilitate processing, the analog signal needs to be normalized when it is converted into a digital signal, so that the dynamic range of the color difference signal is controlled within$-0.5\sim0.5$−0.5∼0.5between.

  After returning to one sentence, the formula is obtained:
$\begin{aligned} &U'=0.564\times (B-Y)=0.564\times (-0.2990\times R-0.5870\times G+0.8860\times B)\\ &V'=0.713\times (R-Y)=0.713\times (0.7010\times R-0.5870\times G-0.1140\times B) \end{aligned}$​U′=0.564×(B−Y)=0.564×(−0.2990×R−0.5870×G+0.8860×B)V′=0.713×(R−Y)=0.713×(0.7010×R−0.5870×G−0.1140×B)​
  Due to the above$U'、V'$U′、V′The value range of$\pm 350mv$±350mvBetween, so you need to introduce$+350mv$+350mv bias. The formula becomes:
$\begin{aligned} &U''=0.564\times (B-Y)+0.35\\ &V''=0.713\times (R-Y)+0.35 \end{aligned}$​U′′=0.564×(B−Y)+0.35V′′=0.713×(R−Y)+0.35​

Code level distribution after luminance signal quantization

  The code level distribution after the quantization of the luminance signal is shown in the figure (source "Digital TV Broadcasting Principles and Applications" P36):

  It can be seen that the peak white level of the brightness signal corresponds to the code level 235, and the blanking level corresponds to the code level 16. In order to prevent overload caused by signal changes, 20 levels at the upper end and 16 levels at the lower end are used as protection bands for the signal to exceed the dynamic range. The code levels 0 and 255 are protection levels, which are not allowed to appear in the video data stream, and the code words 00 and FF are used to transmit synchronization information. The dynamic range of the luminance signal occupies a total of 220 quantization levels.

Code level distribution after color difference signal quantization

  The code level distribution of the color difference signal is shown in the figure, the source of the picture is "Digital TV Broadcasting Principles and Applications" P37):

  Color difference signal$C_b and C_r$Cb​withCr​The peak white level of the peak corresponds to the code level 240, and the 0 level corresponds to the code level 16. In order to prevent overload caused by signal changes, 15 levels at the upper end and 16 levels at the lower end are used as the protection band for the signal to exceed the dynamic range. The dynamic range of the color difference signal occupies a total of 225 quantization levels.

Code level digital expression

  After the quantization of the luminance signal and the color difference signal, the nearest integer is taken as the code level value. The digitized expression is:
$\begin{aligned} &D_Y=INT[(219Y+16)\times 2^{n-8}]\\ &D_{CB}=INT[(224C_b+128)\times 2^{n-8}]\\ &D_{CR}=INT[(224C_r+128)\times 2^{n-8}]\end{aligned}$​DY​=INT[(219Y+16)×2n−8]DCB​=INT[(224Cb​+128)×2n−8]DCR​=INT[(224Cr​+128)×2n−8]​

  Push the previous$Y,U'',V''$Y,U′′,V′′Bringing into the above formula, you can get:
$\begin{aligned} &Y=(66\times R+129\times G+25\times B)>>8+16\\ &U=(-38\times R-74\times G+112\times B)>>8+128\\ &V=(112\times R-94\times G-18\times B)>>8+128\end{aligned}$​Y=(66×R+129×G+25×B)>>8+16U=(−38×R−74×G+112×B)>>8+128V=(112×R−94×G−18×B)>>8+128​

   Write the expression in the form of a matrix:
$\begin{aligned}\begin{bmatrix}Y\\U\\V\end{bmatrix}=\frac{1}{256}\begin{bmatrix}66&129&25\\-38&-74&112\\112&-94&-18\end{bmatrix}\begin{bmatrix}R\\G\\B\end{bmatrix}+\begin{bmatrix}16\\128\\128\end{bmatrix}\end{aligned}$⎣⎡​YUV​⎦⎤​=2561​⎣⎡​66−38112​129−74−94​25112−18​⎦⎤​⎣⎡​RGB​⎦⎤​+⎣⎡​16128128​⎦⎤​​

   order matrix$\begin{bmatrix}66&129&25\\-38&-74&112\\112&-94&-18\end{bmatrix}$⎣⎡​66−38112​129−74−94​25112−18​⎦⎤​Matrix$A$A, The original formula can be transformed into:$\begin{aligned}\begin{bmatrix}R\\G\\B\end{bmatrix}=256A^{-1}\begin{bmatrix}Y-16\\U-128\\V-128\end{bmatrix}\end{aligned}$⎣⎡​RGB​⎦⎤​=256A−1⎣⎡​Y−16U−128V−128​⎦⎤​​

  Because of$A^{-1}$A−1Is too small, so first$A$AEach element in is reduced to the original$\frac{1}{256\times 256}$256×2561​get$A_1$A1​. Then the above formula is converted to:$\begin{aligned}\begin{bmatrix}R\\G\\B\end{bmatrix}=A_1^{-1}\begin{bmatrix}Y-16\\G-128\\B-128\end{bmatrix}\div 256\end{aligned}$⎣⎡​RGB​⎦⎤​=A1−1​⎣⎡​Y−16G−128B−128​⎦⎤​÷256​

  Rounding the coefficient to the whole, the following formula can be obtained:
$\begin{aligned} &R=(298\times Y+411\times V-57376) >>8 \\ &G=(298\times Y-101\times U-211\times V+35168)>>8 \\ &B=(298\times Y+519\times U-71200)>>8 \end{aligned}$​R=(298×Y+411×V−57376)>>8G=(298×Y−101×U−211×V+35168)>>8B=(298×Y+519×U−71200)>>8​

1.2 File storage format

  Check the information,$RGB$RGBThe file storage format is$BGR BGR BGR\cdots$BGRBGRBGR⋯,$YUV$YUVThe file storage format is first save all$Y$Y, Save all$U$UAnd finally save all$V$V。

2.1 Representation

  One program$main()$main()The function can contain two parameters:

• The first parameter is$int$intTypes of;
• The second parameter is a string array;

  Usually, the first parameter is named$argc$argc, The second parameter is$argv$argv. Since the declaration of the string array in the function header can have two forms, so$main()$main()There are also two ways to write functions.

1. $main()$main()functionWriting one：

   int main(int argc, char** argv){ return 0;}

2. $main()$main()functionWriting two:

   int main(int argc, char* argv[]){ return 0;}

2.2 How to use

• The meaning of the parameters:

    int argc​: Represents the number of strings.argc = 1 + the number of strings entered by the user, The value of argc is calculated automatically by the operating system, and the programmer does not need to assign it.

    char argv[]*: It stores multiple strings, the form of the string is as follows:

  argv[0] = the name of the executable file. For example, change.exe. (This string does not require user input, and is the same as argc, which can be automatically generated by the operating system.

  argv[1] = string 1

  argv[2] = string 2

  argv[3] = string 3

  ​ $\vdots$⋮

• How to input parameters in programming mode?

  The platform used is$Visual Studio 2019$VisualStudio2019, The file to be used is$down.rgb$down.rgb, The file to be generated is$up.yuv,cho.rgb$up.yuv,cho.rgb,The steps of parameter input are shown in the following figure:

1. Open the properties window of the upper taskbar debugging interface
2. Select debug in configuration properties
3. Modify the command parameters as required

  Based on the above knowledge, the preliminary realization of color space conversion can be easily carried out. Header file$rgb2yuv.h,yuv2rgb.h$rgb2yuv.h,yuv2rgb.hAnd source files$main.cpp,rgb2yuv.cpp,yuv2rgb.cpp$main.cpp,rgb2yuv.cpp,yuv2rgb.cppcomposition.

  Solution Explorer is shown in the figure below:

  Experiment codeas follows:

main.cpp

#include <iostream>#include <cstdio>#include <fstream>#include "rgb2yuv.h"#include "yuv2rgb.h"using namespace std;#define size 196608#define usize 65536#define vsize 131072using namespace std;int main(int argc, char** argv){ifstream infile(argv[1],ios::binary);ofstream outYUV(argv[2], ios::binary);ofstream outRGB(argv[3], ios::binary);if (!infile) { cout << "error to open file1!" << endl; }if (!outYUV) { cout << "error to open file2" << endl; }if (!outRGB) { cout << "error to open file3" << endl; }unsigned char* in = new unsigned char[size];unsigned char* YUV = new unsigned char[size];unsigned char* RGB = new unsigned char[size];infile.read((char*)in, size);rgb2yuv(in,YUV,size, usize, vsize);//First conversionyuv2rgb(YUV, RGB, usize, vsize);//The second conversion/*for (int i = 0; i < size; i++){if (abs(in[i] - RGB[i]) > 5)cout << "i=" << i << " in[" << i << "]=" << int(in[i]) << " RGB[" << i << "]=" << int(RGB[i]) << endl;}*/outYUV.write((char*)YUV, size);outRGB.write((char*)RGB, size);delete in;delete YUV;delete RGB;infile.close();outYUV.close();outRGB.close();return 0;}

rgb2yuv.h

#pragma oncevoid rgb2yuv(unsigned char* rgb, unsigned char* yuv, int size,int usize,int vsize);

rgb2yuv.cpp

void rgb2yuv(unsigned char* rgb, unsigned char* yuv,int size,int usize,int vsize){unsigned char r, g, b, y, u, v;int j = 0;for (int i = 0;i < size;){b = *(rgb + i);g = *(rgb + i + 1);r = *(rgb + i + 2);y = ((66 * r + 129 * g + 25 * b) >> 8) + 16;u = ((-38 * r - 74 * g + 112 * b) >> 8) + 128;v = ((112 * r - 94 * g - 18 * b) >> 8) + 128;*(yuv + j) = y;*(yuv + j + usize) = u;*(yuv + j + vsize) = v;i = i + 3;//Each rgb is 1 groupj++;}}

yuv2rgb.h

#pragma oncevoid yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize);

yuv2rgb.cpp

#pragma once#include "yuv2rgb.h"#include <iostream>using namespace std;void yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize){unsigned char r, g, b, y, u, v;int j = 0;for (int i = 0; i < usize; i++){y = *(yuv + i);u = *(yuv + i + usize);v = *(yuv + i + vsize);r = (298 * y + 411 * v - 57344) >> 8;g = (298 * y - 101 * u - 211 * v + 34739) >> 8;b = (298 * y + 519 * u - 71117) >> 8;*(rgb + j) = b;*(rgb + j + 1) = g;*(rgb + j + 2) = r;j = j + 3;}}

Experimental results

down.rgb	up.yuv	cho.rgb

among them,$down.rgb$down.rgbwith$cho.rgb$cho.rgbuse$YUVviewerPlus$YUVviewerPlusThe way to open is:

  The opened image is an inverted image (due to$bmp$bmpThe image format is stored backwards, so$.rgb$.rgbImage use$bmp$bmpIt will fall when the mode is opened). The pictures in the above table have been rotated using WeChat for easy identification, but$YUV$YUVFiles and$RGB$RGBThere is still mirror flipping between files, but it does not affect viewing and comparison.

  $up.yuv$up.yuvuse$YUVviewerPlus$YUVviewerPlusThe way to open is:

  It can be seen from the comparison chart of the three images,$RGB to YUV$RGBtoYUV'S experiment was successfully completed, and$YUVtoRGB$YUVtoRGBThere is a problem with the experiment, which is transferred out$cho.rgb$cho.rgbThere are more red noise in the image.

Error correction

  Inferred available, in progress$YUVtoRGB$YUVtoRGBWhen you get$RGB$RGBThree figures may exceed$unsigned\ char$unsignedcharThe range that the type can represent, that is, possible$<0$<0or$>255$>255。

   So it’s necessary to$yuv2rgb.cpp$yuv2rgb.cppThe file is appropriately revised,$>255$>255Values ​​are direct$=255$=255,$<0$<0Values ​​are direct$=0$=0。

  After modification$yuv2rgb.cpp$yuv2rgb.cppIs as follows:

#pragma once#include "yuv2rgb.h"#include <iostream>using namespace std;void yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize){int r, g, b, y, u, v;int j = 0;for (int i = 0; i < usize; i++){y = int(*(yuv + i));u = int(*(yuv + i + usize));v = int(*(yuv + i + vsize));r = (298 * y + 411 * v - 57344) >> 8;if (r > 255) { r = 255; }if (r < 0) { r = 0; }g = (298 * y - 101 * u - 211 * v + 34739) >> 8;if (g > 255) { g = 255; }if (g < 0) { g = 0; }b = (298 * y + 519 * u - 71117) >> 8;if (b > 255) { b = 255; }if (b < 0) { b = 0; }*(rgb + j) = unsigned char(b);*(rgb + j + 1) = unsigned char(g);*(rgb + j + 2) = unsigned char(r);j = j + 3;}}

Experimental results

down.rgb	up.yuv	cho.rgb

  So far, almost done$RGB to YUV$RGBtoYUVwith$YUVtoRGB$YUVtoRGBTwo experiments.

  Using a lookup table to optimize the code. Header file$yuvrgb.h$yuvrgb.hAnd source files$main.cpp,yuvrgb.cpp$main.cpp,yuvrgb.cppcomposition.

  Solution Explorer is shown in the figure below:

main.cpp

#include <iostream>#include <cstdio>#include <fstream>#include "yuvrgb.h"using namespace std;#define size 196608#define usize 65536#define vsize 131072#define height 256#define weight 256//Lookup table initializationint* RGBYUV298 = new int[256];int* RGBYUV411 = new int[256];int* RGBYUV101 = new int[256];int* RGBYUV211 = new int[256];int* RGBYUV519 = new int[256];int* RGBYUV66 = new int[256];int* RGBYUV129 = new int[256];int* RGBYUV25 = new int[256];int* RGBYUV38 = new int[256];int* RGBYUV74 = new int[256];int* RGBYUV112 = new int[256];int* RGBYUV94 = new int[256];int* RGBYUV18 = new int[256];int main(int argc, char** argv){initLookupTable();ifstream infile(argv[1],ios::binary);ofstream outYUV(argv[2], ios::binary);ofstream outRGB(argv[3], ios::binary);if (!infile) { cout << "error to open file1!" << endl; }if (!outYUV) { cout << "error to open file2" << endl; }if (!outRGB) { cout << "error to open file3" << endl; }unsigned char* infi = new unsigned char[size];unsigned char* YUVfi = new unsigned char[size];unsigned char* RGBfi = new unsigned char[size];infile.read((char*)infi, size);rgb2yuv(infi, YUVfi, size, usize, vsize);yuv2rgb(YUVfi, RGBfi, usize, vsize);outYUV.write((char*)YUVfi, size);outRGB.write((char*)RGBfi, size);fileend(infi,YUVfi,RGBfi);infile.close();outYUV.close();outRGB.close();return 0;}

yuvrgb.h

#pragma oncevoid yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize);void rgb2yuv(unsigned char* rgb, unsigned char* yuv, int size, int usize, int vsize);void initLookupTable();void fileend(unsigned char* infi, unsigned char* YUVfi, unsigned char* RGBfi);

yuvrgb.cpp

#pragma once#include "yuvrgb.h"#include <iostream>using namespace std;extern int* RGBYUV298;extern int* RGBYUV411;extern int* RGBYUV101;extern int* RGBYUV211;extern int* RGBYUV519;extern int* RGBYUV66 ;extern int* RGBYUV129;extern int* RGBYUV25 ;extern int* RGBYUV38 ;extern int* RGBYUV74 ;extern int* RGBYUV112;extern int* RGBYUV94 ;extern int* RGBYUV18 ;void initLookupTable(){for (int i = 0; i < 256; i++){RGBYUV298[i] = 298 * i;RGBYUV411[i] = 411 * i;RGBYUV101[i] = 101 * i;RGBYUV211[i] = 211 * i;RGBYUV519[i] = 519 * i;RGBYUV66[i] = 66 * i;RGBYUV129[i] = 129 * i;RGBYUV25[i] = 25 * i;RGBYUV38[i] = 38 * i;RGBYUV74[i] = 74 * i;RGBYUV112[i] = 112 * i;RGBYUV94[i] = 94 * i;RGBYUV18[i] = 18 * i;}}void yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize){int r, g, b, y, u, v;int j = 0;for (int i = 0; i < usize; i++){y = int(*(yuv + i));u = int(*(yuv + i + usize));v = int(*(yuv + i + vsize));/*r = (298 * y + 411 * v - 57344) >> 8;*/r = (RGBYUV298[y]+ RGBYUV411[v]-57344)>>8;if (r > 255) { r = 255; }if (r < 0) { r = 0; }/*g = (298 * y - 101 * u - 211 * v + 34739) >> 8;*/g = (RGBYUV298[y] - RGBYUV101[u] - RGBYUV211[v] + 34739) >> 8;if (g > 255) { g = 255; }if (g < 0) { g = 0; }/*b = (298 * y + 519 * u - 71117) >> 8;*/b = (RGBYUV298[y] + RGBYUV519[u] - 71117) >> 8;if (b > 255) { b = 255; }if (b < 0) { b = 0; }*(rgb + j) = unsigned char(b);*(rgb + j + 1) = unsigned char(g);*(rgb + j + 2) = unsigned char(r);j = j + 3;}}void rgb2yuv(unsigned char* rgb, unsigned char* yuv, int size, int usize, int vsize){int r, g, b, y, u, v;int j = 0;for (int i = 0; i < size;){b = int(*(rgb + i));g = int(*(rgb + i + 1));r = int(*(rgb + i + 2));/*y = ((66 * r + 129 * g + 25 * b) >> 8) + 16;*/y = ((RGBYUV66[r] + RGBYUV129[g] + RGBYUV25[b]) >> 8) + 16;/*u = ((-38 * r - 74 * g + 112 * b) >> 8) + 128;*/u = ((-RGBYUV38[r] - RGBYUV74[g] + RGBYUV112[b]) >> 8) + 128;/*v = ((112 * r - 94 * g - 18 * b) >> 8) + 128;*/v = ((RGBYUV112[r] - RGBYUV94[g] - RGBYUV18[b]) >> 8) + 128;/*if ((y > 255) || (u > 255) || (v > 255) || (y < 0) || (u < 0) || (v < 0)){cout << "y=" << y << "u=" << u << "v=" << v << endl;}*/*(yuv + j) = unsigned char(y);*(yuv + j + usize) = unsigned char(u);*(yuv + j + vsize) = unsigned char(v);i = i + 3;//Each rgb is 1 groupj++;}}void fileend(unsigned char* infi, unsigned char* YUVfi, unsigned char* RGBfi){delete infi;delete YUVfi;delete RGBfi;deleteRGBYUV298;deleteRGBYUV411;deleteRGBYUV101;deleteRGBYUV211;deleteRGBYUV519;deleteRGBYUV66;deleteRGBYUV129;deleteRGBYUV25;deleteRGBYUV38;deleteRGBYUV74;deleteRGBYUV112;deleteRGBYUV94;deleteRGBYUV18;}

Experimental results

down.rgb	up.yuv	cho.rgb

  So far, 4:4:4 is completed$RGB$RGBFile with 4:4:4$YUV$YUVConversion between files.

  As shown in the figure, it is a 4:2:0 chroma sampling format. So you can get from 4:4:4$YUV$YUVThe file is converted to 4:2:0$YUV$YUVThe idea of ​​the document is to keep the original$Y$YWeight,$U$USignal and$V$VThe signals are all odd points in odd rows. So slightly modify the original code, and add a 4:4:4 according to the above idea$YUV$YUVFile gets 4:2:0$YUV$YUVThe function of the file can be realized from$RGB$RGBFile to$4：2：0YUV$4：2：0YUVFile conversion.

  About from$4：2：0YUV$4：2：0YUVFile to$RGB$RGBFile conversion, due to the correlation between pixels, it is conceivable that the original$Y$YWeight,$UV$UVThe components can be copied to get the missing$UV$UVWeight, re-converted to 4:4:4$YUV$YUVfile. According to the above ideas, add a 4:2:0$YUV$YUVFile gets 4:4:4$YUV$YUVThe function of the file can be realized from$4：2：0YUV$4：2：0YUVFile to$RGB$RGBFile conversion.

  The experiment code is as follows:

main.cpp

#include <iostream>#include <cstdio>#include <fstream>#include "yuvrgb.h"using namespace std;#define size 196608#define csize 98304#define usize 65536#define vsize 131072#define height 256#define weight 256//Lookup table initializationint* RGBYUV298 = new int[256];int* RGBYUV411 = new int[256];int* RGBYUV101 = new int[256];int* RGBYUV211 = new int[256];int* RGBYUV519 = new int[256];int* RGBYUV66 = new int[256];int* RGBYUV129 = new int[256];int* RGBYUV25 = new int[256];int* RGBYUV38 = new int[256];int* RGBYUV74 = new int[256];int* RGBYUV112 = new int[256];int* RGBYUV94 = new int[256];int* RGBYUV18 = new int[256];int main(int argc, char** argv){initLookupTable();ifstream infile(argv[1],ios::binary);ofstream outYUV444(argv[2], ios::binary);ofstream outYUV420(argv[3], ios::binary);ofstream outYUV4442(argv[4], ios::binary);ofstream outRGB(argv[5], ios::binary);if (!infile) { cout << "error to open file1!" << endl; }if (!outYUV444) { cout << "error to open file2" << endl; }if (!outYUV420) { cout << "error to open file3" << endl; }if (!outYUV4442) { cout << "error to open file4" << endl; }if (!outRGB) { cout << "error to open file5" << endl; }unsigned char* infi = new unsigned char[size];unsigned char* YUV444fi = new unsigned char[size];unsigned char* YUV420fi = new unsigned char[csize];unsigned char* YUV4442fi = new unsigned char[size];unsigned char* RGBfi = new unsigned char[size];infile.read((char*)infi, size);rgb2yuv(infi, YUV444fi, size, usize, vsize);yuv444Tyuv420(YUV444fi,YUV420fi,size,weight);yuv420Tyuv444(YUV420fi, YUV4442fi, size, weight);yuv2rgb(YUV4442fi, RGBfi, usize, vsize);outYUV444.write((char*)YUV444fi, size);outYUV420.write((char*)YUV420fi, csize);outYUV4442.write((char*)YUV4442fi, size);outRGB.write((char*)RGBfi, csize);fileend(infi,YUV444fi,YUV420fi,RGBfi);infile.close();outYUV444.close();outYUV420.close();outRGB.close();return 0;}

yuvrgb.h

#pragma oncevoid initLookupTable();void yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize);void rgb2yuv(unsigned char* rgb, unsigned char* yuv, int size, int usize, int vsize);void fileend(unsigned char* infi, unsigned char* YUV444fi, unsigned char* YUV420fi, unsigned char* RGBfi);void yuv444Tyuv420(unsigned char* yuv444,unsigned char* yuv420,int size,int weight);void yuv420Tyuv444(unsigned char* YUV420, unsigned char* YUV444, int size, int weight);

yuvrgb.cpp

#pragma once#include "yuvrgb.h"#include <iostream>using namespace std;extern int* RGBYUV298;extern int* RGBYUV411;extern int* RGBYUV101;extern int* RGBYUV211;extern int* RGBYUV519;extern int* RGBYUV66 ;extern int* RGBYUV129;extern int* RGBYUV25 ;extern int* RGBYUV38 ;extern int* RGBYUV74 ;extern int* RGBYUV112;extern int* RGBYUV94 ;extern int* RGBYUV18 ;void initLookupTable(){for (int i = 0; i < 256; i++){RGBYUV298[i] = 298 * i;RGBYUV411[i] = 411 * i;RGBYUV101[i] = 101 * i;RGBYUV211[i] = 211 * i;RGBYUV519[i] = 519 * i;RGBYUV66[i] = 66 * i;RGBYUV129[i] = 129 * i;RGBYUV25[i] = 25 * i;RGBYUV38[i] = 38 * i;RGBYUV74[i] = 74 * i;RGBYUV112[i] = 112 * i;RGBYUV94[i] = 94 * i;RGBYUV18[i] = 18 * i;}}void yuv2rgb(unsigned char* yuv, unsigned char* rgb,int usize,int vsize){int r, g, b, y, u, v;int j = 0;for (int i = 0; i < usize; i++){y = int(*(yuv + i));u = int(*(yuv + i + usize));v = int(*(yuv + i + vsize));r = (RGBYUV298[y]+ RGBYUV411[v]-57344)>>8;if (r > 255) { r = 255; }if (r < 0) { r = 0; }g = (RGBYUV298[y] - RGBYUV101[u] - RGBYUV211[v] + 34739) >> 8;if (g > 255) { g = 255; }if (g < 0) { g = 0; }b = (RGBYUV298[y] + RGBYUV519[u] - 71117) >> 8;if (b > 255) { b = 255; }if (b < 0) { b = 0; }*(rgb + j) = unsigned char(b);*(rgb + j + 1) = unsigned char(g);*(rgb + j + 2) = unsigned char(r);j = j + 3;}}void rgb2yuv(unsigned char* rgb, unsigned char* yuv, int size, int usize, int vsize){int r, g, b, y, u, v;int j = 0;for (int i = 0; i < size;){b = int(*(rgb + i));g = int(*(rgb + i + 1));r = int(*(rgb + i + 2));y = ((RGBYUV66[r] + RGBYUV129[g] + RGBYUV25[b]) >> 8) + 16;u = ((-RGBYUV38[r] - RGBYUV74[g] + RGBYUV112[b]) >> 8) + 128;v = ((RGBYUV112[r] - RGBYUV94[g] - RGBYUV18[b]) >> 8) + 128;*(yuv + j) = unsigned char(y);*(yuv + j + usize) = unsigned char(u);*(yuv + j + vsize) = unsigned char(v);i = i + 3;//Each rgb is 1 groupj++;}}void yuv444Tyuv420(unsigned char* yuv444, unsigned char* yuv420,int size,int weight){int Ysize = size / 3;int j = 0;for (int i = 0; i < Ysize; i++)//Calculation of Y component{*(yuv420 + j) = *(yuv444 + i);j++;}for (int i = 0; i < Ysize; )//Calculation of U component{if (i % 2 == 1){i++;continue;}if ((i) % (2 * weight) == 0){i = i + weight;continue;}*(yuv420 + j) = *(yuv444 + i + Ysize);j++;i++;}for (int i = 0; i < Ysize; )//Calculation of U component{if (i % 2 == 1){i++;continue;}if ((i) % (2 * weight) == 0){i = i + weight;continue;}*(yuv420 + j) = *(yuv444 + i + Ysize + Ysize);j++;i++;}}void yuv420Tyuv444(unsigned char* YUV420, unsigned char* YUV444, int size, int weight){int Ysize = size / 3;int j = 0;for (int i = 0; i < Ysize; i++)//Calculation of Y component{*(YUV444 + i) = *(YUV420 + j);j++;}for (int i = 0; i < Ysize; )//Calculation of U component{if (i % 2 == 1){j = j - 1;*(YUV444 + i + Ysize) = *(YUV420 + j);i++;j++;continue;}if ((i) % (2 * weight) == 0){j = j - weight/2;*(YUV444 + i + Ysize) = *(YUV420 + j);i++;j++;continue;}*(YUV444 + i + Ysize) = *(YUV420 + j);j++;i++;}for (int i = 0; i < Ysize; )//Calculation of U component{if (i % 2 == 1){j = j - 1;*(YUV444 + i + Ysize + Ysize) = *(YUV420 + j);i++;j++;continue;}if ((i) % (2 * weight) == 0){j = j - weight/2;*(YUV444 + i + Ysize + Ysize) = *(YUV420 + j);i++;j++;continue;}*(YUV444 + i + Ysize + Ysize) = *(YUV420 + j);j++;i++;}}void fileend(unsigned char* infi, unsigned char* YUV444fi,unsigned char* YUV420fi, unsigned char* RGBfi){delete infi;delete YUV444fi;delete YUV420fi;delete RGBfi;deleteRGBYUV298;deleteRGBYUV411;deleteRGBYUV101;deleteRGBYUV211;deleteRGBYUV519;deleteRGBYUV66;deleteRGBYUV129;deleteRGBYUV25;deleteRGBYUV38;deleteRGBYUV74;deleteRGBYUV112;deleteRGBYUV94;deleteRGBYUV18;}