Okay, so sometimes it's really IMPORTANT to get the exact color you want, only it's not *IN* the Image, and ImageColorResolve just isn't "close enough".
The following code is a disgustingly gross hack, rather slow, but it does that.
$colorcount = array();
for ($x = 0; $x < $width; $x++){
for ($y = 0; $y < $height; $y++){
$colorindex = imagecolorat($jpg, $x, $y);
if (!isset($colorcount[$colorindex])){
$colorcount[$colorindex] = 1;
}
else{
$colorcount[$colorindex]++;
}
}
}
asort($colorcount);
reset($colorcount);
$black = imagecolorexact($jpg, 0, 0, 0);
if ($black == -1){
$goner = key($colorcount);
$rgb = imagecolorsforindex($jpg, $goner);
#error_log("Need black: About to kill $goner ($rgb[red], $rgb[green], $rgb[blue]) which was only used in $colorcount[$goner] pixels", 0);
unset($colorcount[$goner]);
imagecolordeallocate($jpg, $goner);
$black = imagecolorallocate($jpg, 0, 0, 0);
}
if ($black == -1){
$black = imagecolorresolve($jpg, 0, 0, 0);
#error_log("Damn! STILL couldn't allocate the color!", 0);
}
imagecolorresolve
(PHP 4, PHP 5, PHP 7, PHP 8)
imagecolorresolve — Get the index of the specified color or its closest possible alternative
Description
This function is guaranteed to return a color index for a requested color, either the exact color or the closest possible alternative.
If you created the image from a file, only colors used in the image are resolved. Colors present only in the palette are not resolved.
Parameters
-
image -
A GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
-
red -
Value of red component.
-
green -
Value of green component.
-
blue -
Value of blue component.
Return Values
Returns a color index.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
image expects a GdImage
instance now; previously, a valid gd resource was expected.
|
Examples
Example #1 Using imagecoloresolve() to get colors from an image
<?php
// Load an image
$im = imagecreatefromgif('phplogo.gif');
// Get closest colors from the image
$colors = array();
$colors[] = imagecolorresolve($im, 255, 255, 255);
$colors[] = imagecolorresolve($im, 0, 0, 200);
// Output
print_r($colors);
imagedestroy($im);
?>The above example will output something similar to:
Array
(
[0] => 89
[1] => 85
)
See Also
- imagecolorclosest() - Get the index of the closest color to the specified color
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User Contributed Notes 1 note
ceo at l-i-e dot com ¶
22 years ago
