如何計算兩種顏色之間的差異（亮度，亮度，顏色）？

Question

如何計算

• 亮度對比度，
• 的亮度差，和
• 的差在顏色

兩個給定的顏色之間？

實施例：

輸入

• 顏色1：＃99CCFF
• 顏色2：＃225588

輸出

• 光度對比度：4.57：1的亮度
• 差：在顏色119
• 差：357

Answer 1

從轉換各顏色（R，G，B）到（H，S， V）[或（H，S，L）]座標。你可以找到公式at Wikipedia。

我已經寫帕斯卡爾功能如下：

function RGBToHSV(const Color: TRGB): THSV; 
var 
    cmax, cmin, cdiff: real; 
begin 
    cmax := MaxComponent(Color); 
    cmin := MinComponent(Color); 
    cdiff := cmax - cmin; 

    with Color, result do 
    begin 

    // Hue 
    if cmax = cmin then 
     hsvHue := 0 
    else if cmax = rgbRed then 
     hsvHue := (60 * (rgbGreen - rgbBlue)/cdiff) 
    else if cmax = rgbGreen then 
     hsvHue := (60 * (rgbBlue - rgbRed)/cdiff) + 120 
    else 
     hsvHue := (60 * (rgbRed - rgbGreen)/cdiff) + 240; 

    hsvHue := Fix360(hsvHue); 

    // Saturation 
    if cmax = 0 then 
     hsvSaturation := 0 
    else 
     hsvSaturation := 1 - cmin/cmax; 

    // Value 
    hsvValue := cmax; 

    end; 

end; 

function RGBToHSL(const Color: TRGB): THSL; 
var 
    cmax, cmin, cdiff, csum: real; 
begin 
    cmax := MaxComponent(Color); 
    cmin := MinComponent(Color); 
    cdiff := cmax - cmin; 
    csum := cmax + cmin; 

    with Color, result do 
    begin 

    // Hue 
    if cmax = cmin then 
     hslHue := 0 
    else if cmax = rgbRed then 
     hslHue := (60 * (rgbGreen - rgbBlue)/cdiff) 
    else if cmax = rgbGreen then 
     hslHue := (60 * (rgbBlue - rgbRed)/cdiff) + 120 
    else 
     hslHue := (60 * (rgbRed - rgbGreen)/cdiff) + 240; 

    hslHue := Fix360(hslHue); 

    // Saturation 
    if cmax = cmin then 
     hslSaturation := 0 
    else if csum <= 1 then 
     hslSaturation := cdiff/csum 
    else 
     hslSaturation := cdiff/(2 - csum); 

    // Lightness 
    hslLightness := csum/2; 

    end; 

end;