通过RGB或YUV改变图像的色度和饱和度

通过RGB或YUV改变图像的色度和饱和度

引用

CSDN

1.

https://blog.csdn.net/u013066730/article/details/129768155

本文介绍了通过RGB和YUV两种颜色空间来调整图像的色度和饱和度的方法。文章内容包括具体的数学公式、代码实现以及效果展示，具有一定的技术深度和实用性。

1.RGB调整饱和度

通过RGB改变图像的饱和度，参数r的范围一般为（-1，+5）。

公式：

B = B + (B-(R+G)/2)*r;
G = G + (G-(R+B)/2)*r;
R = R + (R-(B+G)/2)*r;

效果图：

2.YUV介绍

在YUV空间，Y代表亮度，U和V（又称CR和CB）代表色度偏红和偏紫。要改变饱和度需要将U和V同比例地增加和减少。

2.1 YUV调整饱和度（有缺陷，颜色会有点偏移）

通过YUV改变图像的饱和度，这里的r的范围一般为(0, 5)。如果r为1，则表示不改变图像数据。

公式如下：

Y = Y;
U = U*r;
V = V*r;

注意：这里的U和V的范围是（-128, 128）。如果UV的范围是0-255或16-240，那么就需要先减去128。

效果图：

2.2 YUV调整色相

通过YUV改变图像的色相（Cb即为U，Cr即为V），UV的范围是（-128, 128）。

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%调节色度
% U' = (U-128) x Cos(H) + (V-128) x Sin(H)
% V' = (V-128) x Cos(H) - (U-128) x Sin(H)
H1=120;
H1=H1/180*pi;
for i=1:m
   for j=1:n 
       Cb1(i,j) =(Cb1(i,j)-128)*sin(H1) +(Cr1(i,j)-128)*cos(H1)+128;
       Cr1(i,j) =(Cr1(i,j)-128)*sin(H1) -(Cb1(i,j)-128)*cos(H1)+128;
   end
end
H2=60;
H2=H2/180*pi;
for i=1:m
   for j=1:n 
       Cb2(i,j) =(Cb2(i,j)-128)*sin(H2) +(Cr2(i,j)-128)*cos(H2)+128;
       Cr2(i,j) =(Cr2(i,j)-128)*sin(H2) -(Cb2(i,j)-128)*cos(H2)+128;
   end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

2.3 调整对比度

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
C1=0.5;
C2=2;
for i=1:m
   for j=1:n 
       temp = (Y1(i,j)-128)*C1 + 128;
       Y1(i,j) = min(max(temp, 0), 255);
   end
end
 
for i=1:m
   for j=1:n 
       temp = (Y2(i,j)-128)*C2 + 128;
       Y2(i,j) = min(max(temp, 0), 255);
   end
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

原文链接：通过RGB或YUV改变图像的色度和饱和度_rgb怎么改饱和度-CSDN博客