近似選擇顏色區域

Question

有誰知道圖像處理器（如Photoshop或Gimp）用於選擇具有相似顏色的區域的方法的名稱？另外，任何人都可以指出一些鏈接來解釋這種方法（如果可能的話，用C++代碼）？

Answer 1

如果您有興趣，這可能是一個檢查顏色是否與另一個顏色相似的示例。 它也使用寬容作爲來自gimp和paint.net的魔杖。

然而，這個例子比較了價值的差異，而不是顏色或亮度的差異。

/*\ function to check if the color at this position is similar to the one you chose 
|* Parameters: 
|* int color  - the value of the color of choice 
|* int x   - position x of the pixel 
|* int y   - position y of the pixel 
|* float tolerance - how much this pixels color can differ to still be considered similar 
\*/ 

bool isSimilar(int color, int x, int y, float tolerance) 
{ 
    // calculate difference between your color and the max value color can have 
    int diffMaxColor = 0xFFFFFF - color; 
    // set the minimum difference between your color and the minimum value of color 
    int diffMinColor = color; 
    // pseudo function to get color (could return 'colorMap[y * width + x];') 
    int chkColor = getColor(x, y); 
    // now checking whether or not the color of the pixel is in the range between max and min with tolerance 
    if(chkColor > (color + (diffMaxColor * tolerance)) || chkColor < ((1 - tolerance) * diffMinColor)) 
    { 
     // the color is outside our tolerated range 
     return false; 
    } 
    // the color is inside our tolerated range 
    return true; 
}