The imagecolorclosest() function is an inbuilt function in PHP which is used to get the index of the closest color in the given image. This function returns the index of the color in the palette of the image which is closest to the specified RGB value.
Syntax:
int imagecolorclosest( $image, $red, $green, $blue )
Parameters: This function accepts four parameters as mentioned above and described below:
- $image: It is returned by one of the image creation functions, such as imagecreatetruecolor(). It is used to create size of image.
- $red: This parameter is used to set value of red color component.
- $green: This parameter is used to set value of green color component.
- $blue: This parameter is used to set value of blue color component.
Return Value: This function returns the index of the closest color, in the palette of the image.
Below programs illustrate the imagecolorclosest() function in PHP.
Program 1:
<?php   // Start with an image and convert it to a palette-based image $image = imagecreatefrompng(   imagetruecolortopalette($image, false, 255);   // Search closest color $result = imagecolorclosest($image, 7, 150, 10);   $result = imagecolorsforindex($image, $result);   $result = "({$result['red']}, {$result['green']}, {$result['blue']})";   echo "Closest color: " . $result;   imagedestroy($image);   ?> |
Output:
Closest color: (4, 146, 12)
Program 2:
<?php   // Start with an image and convert it to a palette-based image $image = imagecreatefrompng(   imagetruecolortopalette($image, false, 255);   // Search RGB colors $color = array(     array(7, 150, 0),     array(53, 190, 255),     array(255, 165, 54) );   // Loop to find the closest color to the given RGB color foreach($color as $id => $rgb) {     $result = imagecolorclosest($image, $rgb[0], $rgb[1], $rgb[2]);     $result = imagecolorsforindex($image, $result);     $result = "({$result['red']}, {$result['green']}, {$result['blue']})";       echo "Given color: ($rgb[0], $rgb[1], $rgb[2]) => Closest match: $result<br>"; }   imagedestroy($image);   ?> |
Output:
Given color: (7, 150, 0) => Closest match: (4, 142, 4) Given color: (53, 190, 255) => Closest match: (148, 174, 180) Given color: (255, 165, 54) => Closest match: (148, 162, 164)
Return Value:
Reference: http://php.net/manual/en/function.imagecolorclosest.php
