imagecolormatch

(PHP 4 >= 4.3.0, PHP 5)

imagecolormatch — Faz com que a versão das cores da paleta sejam mais próximas da versão truecolor

Descrição

bool imagecolormatch ( resource $image1 , resource $image2 )

Aviso

Esta função não está documentada; somente a lista de argumentos está disponível.

image1 deve ser Truecolor, image2 deve ser uma paleta, e ambas image1 e image2 devem ter o mesmo tamanho.

Retorna TRUE em caso de sucesso ou FALSE em caso de falha.

Nota: Esta função somente está disponível se o PHP estiver compilado com a versão embarcada da biblioteca GD.

Nota: This function requires GD 2.0.1 or later (2.0.28 or later is recommended).

Veja também imagecreatetruecolor().

imagecolorresolve

imagecolorexactalpha

[edit] Last updated: Fri, 14 Jun 2013

add a note User Contributed Notes imagecolormatch - [3 notes]

down

gk at karko dot net ¶

2 years ago


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

down

albriNOght at anSPAMre dot net ¶

7 years ago


This 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.

down

Samantha ¶

9 years ago


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.

add a note