PHP imagecolorclosestalpha - made with the specified color + alpha closest color index
imagecolorclosestalpha - index achieved the specified color + alpha closest color.
grammar
int imagecolorclosestalpha ( resource $image , int $red , int $green , int $blue , int $alpha )
Returns the image palette is "closest" to the specified RGB color value and alpha depth.
parameter
- image created by the image function (for example imagecreatetruecolor ()) image resource returned.
- valuered red component.
- green value for the green component.
- blue blue component value.
- alpha a value of between 0 and 127.0 means completely opaque, 127 means completely transparent.
Color parameter is an integer between 0 and 255, or between a hexadecimal number between 0x00 and 0xFF.
return value
Returns the index of the closest color in the palette.
Examples
Search for a set of colors in the image.
<?php // 从一个图像开始,并将其转换为一个基于调色板的图像 $im = imagecreatefrompng('figures/imagecolorclosest.png'); imagetruecolortopalette($im, false, 255); // 搜索颜色 (RGB) $colors = array( array(254, 145, 154, 50), array(153, 145, 188, 127), array(153, 90, 145, 0), array(255, 137, 92, 84) ); // 循环遍历,查找调色板中最接近的颜色 // 返回搜索次数,搜索的 RGB 和最接近的匹配的 RGB foreach($colors as $id => $rgb) { $result = imagecolorclosestalpha($im, $rgb[0], $rgb[1], $rgb[2], $rgb[3]); $result = imagecolorsforindex($im, $result); $result = "({$result['red']}, {$result['green']}, {$result['blue']}, {$result['alpha']})"; echo "#$id: 搜索 ($rgb[0], $rgb[1], $rgb[2], $rgb[3]); 最接近的匹配: $result。\n"; } imagedestroy($im); ?>
Output similar to the above example:
#0: 搜索 (254, 145, 154, 50); 最接近的匹配: (252, 150, 148, 0)。 #1: 搜索 (153, 145, 188, 127); 最接近的匹配: (148, 150, 196, 0)。 #2: 搜索 (153, 90, 145, 0); 最接近的匹配: (148, 90, 156, 0)。 #3: 搜索 (255, 137, 92, 84); 最接近的匹配: (252, 150, 92, 0)。
related articles
- imagecolorexactalpha () Get the index of the specified color + alpha.
- imagecolorclosest () Get the index of the closest color to the specified color.
- imagecolorclosesthwb () to obtain a given color closest to the color of black and white index.