CODEWITHSUNDEEP
phpimage-processinggd
Alesfatalis
Alesfatalis

Reputation: 777

change color of multiple different rgb colors

Hey guys i am trying to recolor the following image with php: enter image description here

I want to give my user the possibility to change the color of the banner with a a few clicks in my php application. So i used this little experimental script i got here

This is my script to change one rgb color of my image:

$imgname = "test.png";
$im = imagecreatefrompng($imgname);
imagealphablending($im, false);
for ($x = imagesx($im); $x--;) {
    for ($y = imagesy($im); $y--;) {
        $rgb = imagecolorat($im, $x, $y);
        $c = imagecolorsforindex($im, $rgb);
        if ($c['red'] == 0 && $c['green'] == 94 && $c['blue'] == 173) { 
            $colorB = imagecolorallocatealpha($im, 255, 0, 255, $c['alpha']);
            imagesetpixel($im, $x, $y, $colorB);
        }
    }
}
imageAlphaBlending($im, true);
imageSaveAlpha($im, true);
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);

The problem is the blue color of the banner are multiple different rgb colors so how can i change all blue rgb colors at once without affecting the other colors.

Upvotes: 0

Views: 269

Answers (1)

Mailerdaimon
Mailerdaimon

Reputation: 6080

Just define a Threshold that holds for all wanted colors.

Change:

 if ($c['red'] == 0 && $c['green'] == 94 && $c['blue'] == 173)

To something like:

if ($c['red'] == 0 && $c['green'] == 94 && $c['blue'] > 173 && $c['blue'] < 240)

Do this for all 3 Channels and Test what color Range fits best.

Upvotes: 2

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