Those that have Ubuntu servers note, that this function is added in PHP's GD library fork and is not available by default in Ubuntu php5-gd package.
Here's how-to install the PHP GD version: http://preview.tinyurl.com/yel4r7t
(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
imagecolormatch — Faz com que as cores da versão em paleta da imagem fiquem mais próximas da versão em cores verdadeiras
Faz com que as cores da versão em paleta da imagem fiquem mais próximas da versão em cores verdadeiras.
image1Um objeto de imagem em cores verdadeiras.
image2
Um objeto de imagem em paleta apontando para uma imagem que tenha o mesmo
tamanho da image1.
| Versão | Descrição |
|---|---|
| 8.0.0 |
image1 e image2 agora esperam instâncias de
GdImage; anteriormente, resources
eram esperados.
|
Exemplo #1 Exemplo de imagecolormatch()
<?php
// Configura as imagens com cores verdadeiras e com paleta
$im1 = imagecreatefrompng('./gdlogo.png');
$im2 = imagecreate(imagesx($im1), imagesy($im1));
// Adiciona algumas cores a $im2
$colors = Array();
$colors[] = imagecolorallocate($im2, 255, 36, 74);
$colors[] = imagecolorallocate($im2, 40, 0, 240);
$colors[] = imagecolorallocate($im2, 82, 100, 255);
$colors[] = imagecolorallocate($im2, 84, 63, 44);
// Faz correspondência dessas cores com a imagem em cores verdadeiras
imagecolormatch($im1, $im2);
// Libera a memória
imagedestroy($im1);
imagedestroy($im2);
?>Those that have Ubuntu servers note, that this function is added in PHP's GD library fork and is not available by default in Ubuntu php5-gd package.
Here's how-to install the PHP GD version: http://preview.tinyurl.com/yel4r7tThis function appears to work by changing the values of the colors of the paletted image -- no good if you're trying to force the resultant image to stick with certain pre-defined color values.This function is a godsend! It works exactly as documented.
I'm working on an application where I need to take a transparent GIF, matte the GIF on a user defined background color, and finally scale the GIF based on a user defined %.
The only way I could get this to work so that the final image was high quality, ie: no jagged edges, and a smooth scale, was to convert the GIF to a JPG, and then copy the JPG into a new GIF image like this:
// open transparent gif
$GIFimg = imagecreatefromgif($file_path);
// create jpg image
$JPGimg = imagecreatetruecolor($width, $height);
// copy GIF to JPG
imagecopy($JPGimg, $GIFimg, 0, 0, 0, 0, $width, $height);
// create a true color image
$JPGscaled = imagecreatetruecolor($n_width, $n_height);
// scale the new JPG using the truecolor image
imagecopyresampled($JPGscaled, $JPGimg, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
// create final GIF image
$GIFfinal = imagecreate($n_width, $n_height);
// copy the scaled JPG back to a GIF
imagecopymerge($GIFfinal, $JPGscaled, 0, 0, 0, 0, $n_width, $n_height, 100);
This worked great except the final step, copying the JPG to a GIF. If the JPG had too many colors, the function would index the colors to make it a palette image. So what would end up happening is the final image contained INCORRECT colors.
Adding this one line at the bottom of the code fixed everything.
imagecolormatch($JPGscaled, $GIFfinal);
I hope this helps anyone who is converting images back and forth and dealing with palette issues and color correction. Also, be aware that the above code is a sample and will not work by copying and pasting.