RGB转换为NV12的代码

　　如何将RGB转换为NV12？

　　首先将RGB转换为YUV。这个容易。问题在于，NV12是YYYY YYYY UVUV这样的格式，Y的个数等于像素，而U、V分别是像素个数的1/4。这就有点……

　　最后终于在github找到了可行代码，经过测试、修改，确实可行。

增加了一个step，RGB为3，RGBA为4。
性能较差。再想办法解决。

　　代码链接是：

https://github.com/cohenrotem/Rgb2NV12/


//https://software.intel.com/en-us/node/503873
//YCbCr Color Model:
//    The YCbCr color space is used for component digital video and was developed as part of the ITU-R BT.601 Recommendation. YCbCr is a scaled and offset version of the YUV color space.
//    The Intel IPP functions use the following basic equations [Jack01] to convert between R'G'B' in the range 0-255 and Y'Cb'Cr' (this notation means that all components are derived from gamma-corrected R'G'B'):
//    Y' = 0.257*R' + 0.504*G' + 0.098*B' + 16
//    Cb' = -0.148*R' - 0.291*G' + 0.439*B' + 128
//    Cr' = 0.439*R' - 0.368*G' - 0.071*B' + 128//Y' = 0.257*R' + 0.504*G' + 0.098*B' + 16
static float Rgb2Y(float r0, float g0, float b0)
{float y0 = 0.257f*r0 + 0.504f*g0 + 0.098f*b0 + 16.0f;return y0;
}//U equals Cb'
//Cb' = -0.148*R' - 0.291*G' + 0.439*B' + 128
static float Rgb2U(float r0, float g0, float b0)
{float u0 = -0.148f*r0 - 0.291f*g0 + 0.439f*b0 + 128.0f;return u0;
}//V equals Cr'
//Cr' = 0.439*R' - 0.368*G' - 0.071*B' + 128
static float Rgb2V(float r0, float g0, float b0)
{float v0 = 0.439f*r0 - 0.368f*g0 - 0.071f*b0 + 128.0f;return v0;
}//Convert two rows from RGB to two Y rows, and one row of interleaved U,V.
//I0 and I1 points two sequential source rows.
//I0 -> rgbrgbrgbrgbrgbrgb...
//I1 -> rgbrgbrgbrgbrgbrgb...
//Y0 and Y1 points two sequential destination rows of Y plane.
//Y0 -> yyyyyy
//Y1 -> yyyyyy
//UV0 points destination rows of interleaved UV plane.
//UV0 -> uvuvuv
static void Rgb2NV12TwoRows(const unsigned char I0[],const unsigned char I1[],int step,const int image_width,unsigned char Y0[],unsigned char Y1[],unsigned char UV0[])
{int x;  //Column index//Process 4 source pixels per iteration (2 pixels of row I0 and 2 pixels of row I1).for (x = 0; x < image_width; x += 2){//Load R,G,B elements from first row (and convert to float).float r00 = (float)I0[x*step + 0];float g00 = (float)I0[x*step + 1];float b00 = (float)I0[x*step + 2];//Load next R,G,B elements from first row (and convert to float).float r01 = (float)I0[x*step + step+0];float g01 = (float)I0[x*step + step+1];float b01 = (float)I0[x*step + step+2];//Load R,G,B elements from second row (and convert to float).float r10 = (float)I1[x*step + 0];float g10 = (float)I1[x*step + 1];float b10 = (float)I1[x*step + 2];//Load next R,G,B elements from second row (and convert to float).float r11 = (float)I1[x*step + step+0];float g11 = (float)I1[x*step + step+1];float b11 = (float)I1[x*step + step+2];//Calculate 4 Y elements.float y00 = Rgb2Y(r00, g00, b00);float y01 = Rgb2Y(r01, g01, b01);float y10 = Rgb2Y(r10, g10, b10);float y11 = Rgb2Y(r11, g11, b11);//Calculate 4 U elements.float u00 = Rgb2U(r00, g00, b00);float u01 = Rgb2U(r01, g01, b01);float u10 = Rgb2U(r10, g10, b10);float u11 = Rgb2U(r11, g11, b11);//Calculate 4 V elements.float v00 = Rgb2V(r00, g00, b00);float v01 = Rgb2V(r01, g01, b01);float v10 = Rgb2V(r10, g10, b10);float v11 = Rgb2V(r11, g11, b11);//Calculate destination U element: average of 2x2 "original" U elements.float u0 = (u00 + u01 + u10 + u11)*0.25f;//Calculate destination V element: average of 2x2 "original" V elements.float v0 = (v00 + v01 + v10 + v11)*0.25f;//Store 4 Y elements (two in first row and two in second row).Y0[x + 0]    = (unsigned char)(y00 + 0.5f);Y0[x + 1]    = (unsigned char)(y01 + 0.5f);Y1[x + 0]    = (unsigned char)(y10 + 0.5f);Y1[x + 1]    = (unsigned char)(y11 + 0.5f);//Store destination U element.UV0[x + 0]    = (unsigned char)(u0 + 0.5f);//Store destination V element (next to stored U element).UV0[x + 1]    = (unsigned char)(v0 + 0.5f);}
}//Convert image I from pixel ordered RGB to NV12 format.
//I - Input image in pixel ordered RGB format
//image_width - Number of columns of I
//image_height - Number of rows of I
//J - Destination "image" in NV12 format.//I is pixel ordered RGB color format (size in bytes is image_width*image_height*3):
//RGBRGBRGBRGBRGBRGB
//RGBRGBRGBRGBRGBRGB
//RGBRGBRGBRGBRGBRGB
//RGBRGBRGBRGBRGBRGB
//
//J is in NV12 format (size in bytes is image_width*image_height*3/2):
//YYYYYY
//YYYYYY
//UVUVUV
//Each element of destination U is average of 2x2 "original" U elements
//Each element of destination V is average of 2x2 "original" V elements
//
//Limitations:
//1. image_width must be a multiple of 2.
//2. image_height must be a multiple of 2.
//3. I and J must be two separate arrays (in place computation is not supported).
void Rgb2NV12(const unsigned char I[], int step,const int image_width, const int image_height,unsigned char J[])
{//In NV12 format, UV plane starts below Y plane.unsigned char *UV = &J[image_width*image_height];//I0 and I1 points two sequential source rows.const unsigned char *I0;  //I0 -> rgbrgbrgbrgbrgbrgb...const unsigned char *I1;  //I1 -> rgbrgbrgbrgbrgbrgb...//Y0 and Y1 points two sequential destination rows of Y plane.unsigned char *Y0;    //Y0 -> yyyyyyunsigned char *Y1;    //Y1 -> yyyyyy//UV0 points destination rows of interleaved UV plane.unsigned char *UV0; //UV0 -> uvuvuvint y;  //Row index//In each iteration: process two rows of Y plane, and one row of interleaved UV plane.for (y = 0; y < image_height; y += 2){I0 = &I[y*image_width*step];        //Input row width is image_width*3 bytes (each pixel is R,G,B).I1 = &I[(y+1)*image_width*step];Y0 = &J[y*image_width];            //Output Y row width is image_width bytes (one Y element per pixel).Y1 = &J[(y+1)*image_width];UV0 = &UV[(y/2)*image_width];    //Output UV row - width is same as Y row width.//Process two source rows into: Two Y destination row, and one destination interleaved U,V row.Rgb2NV12TwoRows(I0,I1,step,image_width,Y0,Y1,UV0);}
}

RGB转换为NV12的代码相关推荐

C#实现将RGB颜色值转换为0x颜色代码
在此示例代码中,我们使用Console.ReadLine()函数从用户输入中读取RGB颜色值.接着,我们使用string.Split()函数将RGB颜色值字符串分割为R.G.B三个分量的字符串,并使用 ...
js将颜色rgb转换为16进制
代码如下: //将rgb转换为16进制 function colorRGBtoHex(color) {// console.log(color);var rgb = color.split(','); ...
js 实现rgb和十六进制的代码转化
十六进制转化为RGB function set16ToRgb(str){// 十六进制颜色代码的正则表达式var reg = /^#([0-9A-Fa-f]{3}|[0-9A-Fa-f]{6})$// ...
在上司面前硬不起来？教你如何快速将字符串转换为可执行代码
老是因为活不好被上司欺凌? 在上司面前很没面子? 在上司面前硬不起来? 是时候分享一个可以快速将字符串转换为可执行代码的项目给你了 - YACEP ! 不过,这不 ...
网上流行护眼色的RGB值和颜色代码
网上流行护眼色的RGB值和颜色代码绿豆沙色能有效的减轻长时间用电脑的用眼疲劳! 色调:85,饱和度:123,亮度:205: RGB颜色红:199,绿:237,蓝:204: 十六进制颜色:#C7EDC ...
JS 颜色RGB转换为16进制相互转换方法
/*RGB转换为16进制*/ const colorRgbToHex = (rgbStr: string) => {//十六进制颜色值的正则表达式constreg = /^#([0-9a-fA- ...
labview 转标准c语言,如何将LabVIEW的VI转换为C语言代码
工具链接: SDK: CrackTool: Manul: 如何将LabVIEW的VI转换为C语言代码 (2013-12-11 12:21:34) 如何将LabVIEW的VI转换为C语言代码? 这个问题 ...
labview 转标准c语言,如何将LabVIEW的VI转换为C语言代码..docx
如何将LabVIEW的VI转换为C语言代码方法一:利用LabVIEW的C Generator工具包下载安装LabVIEW 2012软件,下载LabVIEW工具包2012CGenerator.exe ...
(转)网上流行护眼色的RGB值和颜色代码
网上流行护眼色的RGB值和颜色代码绿豆沙色能有效的减轻长时间用电脑的用眼疲劳! 色调:85,饱和度:123,亮度:205: RGB颜色红:199,绿:237,蓝:204: 十六进制颜色:#C7EDC ...
python中颜色空间lab直方图_python – 从RGB转换为LAB色彩空间 – 对L * A * B *值范围的任何了解？...
在OpenCV( Python)中将图像从RGB转换为LAB时,我无法找到有关L * A * B *值范围的文档.寻找一些确认我的洞察力是正确的,因为数字是相当奇特的.我的亮度结果是0-255,但对于 ...

RGB转换为NV12的代码

RGB转换为NV12的代码相关推荐

最新文章

热门文章