[英]How to convert an RGB component to a percentage in C?
如何将RGB分量(0-255)转换为浮点数,其中255为1.0f,0为0.0f?
What's wrong with dividing? 除法有什么问题?
unsigned char red = 45;
float percentage = red/255.0f;
Like this: 像这样:
int rgbValue = 123;
float fpValue = rgbValue / 255.0;
And if you have the entire rgb value in the int you have this option. 如果您在int中拥有整个rgb值,则可以使用此选项。
//Color Component Percents
#define CCP_ALPHA(argb) (((argb) & 0xFF000000) >> 24) / 255.0f
#define CCP_RED(rgb) (((rgb) & 0xFF0000) >> 16) / 255.0f
#define CCP_GREEN(rgb) (((rgb) & 0xFF00) >> 8) / 255.0f
#define CCP_BLUE(rgb) ((rgb) & 0xFF) / 255.0f
int main(int argc, char *argv[])
{
int argb = 0xCCDD33EE;
printf("Alpha %.2f%%\nRed %.2f%%\nGreen %.2f%%\nBlue %.2f%%\n",
CCP_ALPHA(argb) * 100,
CCP_RED(argb) * 100,
CCP_GREEN(argb) * 100,
CCP_BLUE(argb) * 100);
}
Output 输出量
Alpha 80.00%
Red 86.67%
Green 20.00%
Blue 93.33%
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