(PHP 4, PHP 5, PHP 7, PHP 8)
imagecolorset — Define a cor para o índice da paleta especificado
Esta função atribui a cor especificada ao índice especificado na paleta. Isto é útil para criar efeitos de preenchimento em imagens de paleta sem a sobrecarga de realizar verdadeiramente o preenchimento.
imageUm objeto GdImage, retornado por uma das funções de criação de imagem, como imagecreatetruecolor().
colorUm índice na paleta.
redValor do componente vermelho.
greenValor do componente verde.
blueValor do componente azul.
alphaValor do componente alfa.
| Versão | Descrição |
|---|---|
| 8.0.0 |
O parâmetro image agora espera uma instância de GdImage;
anteriormente, um resource gd válido era esperado.
|
Exemplo #1 Exemplo de imagecolorset()
<?php
// Cria uma imagem 300x100
$im = imagecreate(300, 100);
// Define o plano de fundo para vermelho
imagecolorallocate($im, 255, 0, 0);
// Obtém o índice de cor para o plano de fundo
$bg = imagecolorat($im, 0, 0);
// Define o plano de fundo para azul
imagecolorset($im, $bg, 0, 0, 255);
// Mostra a imagem no navegador
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
?>If you want to convert a Color image to Grayscale without creating a blotchy image, use this color calculation:
<?php
function imagetograyscale($im)
{
if (imageistruecolor($im)) {
imagetruecolortopalette($im, false, 256);
}
for ($c = 0; $c < imagecolorstotal($im); $c++) {
$col = imagecolorsforindex($im, $c);
$gray = round(0.299 * $col['red'] + 0.587 * $col['green'] + 0.114 * $col['blue']);
imagecolorset($im, $c, $gray, $gray, $gray);
}
}
?>I've been looking for a simple function which "colorizes" an image, without any success ... it looks like a lot of people mean something different with "colorizing" an image, because actually colorzing means multiplying the old color's grayscale with the new color. So a white pixel would become 100% of the colorize-to-color and a black pixel would stay black (I know I can't explain well ... I hope you understood, otherwise take a look at the example below the functions' code).
<?php
function image_colorize(&$img,$rgb) {
imageTrueColorToPalette($img,true,256);
$numColors = imageColorsTotal($img);
for ($x = 0; $x < $numColors; $x++) {
list($r,$g,$b) = array_values(imageColorsForIndex($img,$x));
// calculate grayscale in percent
$grayscale = ($r + $g + $b) / 3 / 0xff;
imageColorSet($img,$x,
$grayscale * $rgb[0],
$grayscale * $rgb[1],
$grayscale * $rgb[2]
);
}
return true;
}
?>
Example of usage:
<?php
$color = array(0xff,0xaa,0x2a); // color to convert to
$url = 'http://sundog.net/images/uploads/1_google_logo.jpg';
$img = imageCreateFromJpeg($url);
image_colorize($img,$color);
header('Content-type: image/gif');
imageGif($img);
exit;
?>
Enjoythis is helpful if you would like to implement a color theme system in your website... try it out
Davide Candiloro Italy
function colorize ($pngpath, $r, $g, $b)
/*
REQUIRES: $pngpath to be a valid path of a greyscale PNG-8 image with 64 colors palette
$r, $g, $b to be integers in the range 0..255
EFFECTS: returns the png image colorized with the color represented by $r, $g, $b.
*/
{
header("Content-type: image/png");
$im = imagecreatefrompng("images/table.png");
imagetruecolortopalette($im, FALSE, 256);
for ($c = 0; $c < 64; $c++){ /*64 is the number of colors in the PNG-8 palette*/
$col = imagecolorsforindex($im, $c);
imagecolorset ( $im, $c, $r*$col['red']/256, $g*$col['green']/256, $b*$col['blue']/256); /*replaces original greyscale palette with a colorized one*/
}
imagepng($im);
imagedestroy($im);
}here's a function to greyscale an image even from a truecolor source (jpeg or png).
slightly poor quality, but very fast...
function imagegreyscale(&$img, $dither=1) {
if (!($t = imagecolorstotal($img))) {
$t = 256;
imagetruecolortopalette($img, $dither, $t);
}
for ($c = 0; $c < $t; $c++) {
$col = imagecolorsforindex($img, $c);
$min = min($col['red'],$col['green'],$col['blue']);
$max = max($col['red'],$col['green'],$col['blue']);
$i = ($max+$min)/2;
imagecolorset($img, $c, $i, $i, $i);
}
}Here is a function to colorize a picture gradient style.
All you have to do is to pass an img-object and an array of colors.
e.g.
$arr = array('#000000', '#990000', '#00FFFF', '#FFFFDD');
colorize ($img, $arr);
<?php
function colorize($imgdata, $palette)
{
imageTrueColorToPalette($imgdata,false,0xFF);
$l = count($palette)-1;
$i = imagecolorstotal($imgdata);
while ($i--)
{
list($r,$g,$b) = array_values(imageColorsForIndex($imgdata,$i));
$grayscale = ($r*.3 + $g*.59 +$b*.11) / 0xFF;
$pos = $l*$grayscale;
$perc = $pos-floor($pos);
$tbase = str_replace("#", '', $palette[$pos]);
$baseR = hexdec(substr($tbase,0,2));
$baseG = hexdec(substr($tbase,2,2));
$baseB = hexdec(substr($tbase,4,2));
$tmix = str_replace("#", '', $palette[$pos+1]);
$mixR = hexdec(substr($tmix,0,2));
$mixG = hexdec(substr($tmix,2,2));
$mixB = hexdec(substr($tmix,4,2));
$resR = $baseR+($mixR-$baseR)*$perc;
$resG = $baseG+($mixG-$baseG)*$perc;
$resB = $baseB+($mixB-$baseB)*$perc;
imagecolorset($imgdata, $i, $resR, $resG, $resB);
}
}
?>If you are creating a palette image from scratch you have to use imagecolorallocate() for each index before you can use imagecolorset() on it.I had the same problem as heavyraptor2 so i made this function...
<?php
function imagecolorize($im,$endcolor){
//funcion takes image and turns black into $endcolor, white to white and
//everything in between in corresponding gradient
//$endcolor should be 6 char html color
//make sure it has usable palette
if (imageistruecolor($im)) {
imagetruecolortopalette($im, false, 256);
}
//first make it gray to be sure of even results (thanks moxleystratton.com)
//comment this loop if you want the output based on, for example,
//the red channel (for this take a look at the $gray-var in the last loop)
for ($c = 0; $c < imagecolorstotal($im); $c++) {
$col = imagecolorsforindex($im, $c);
$gray = round(0.299 * $col['red'] + 0.587 * $col['green'] + 0.114 * $col['blue']);
imagecolorset($im, $c, $gray, $gray, $gray);
}
//determine end-colors in hexdec
$EndcolorRGB['r'] = hexdec( substr($endcolor, 0, 2));
$EndcolorRGB['g'] = hexdec( substr($endcolor, 2, 2));
$EndcolorRGB['b'] = hexdec( substr($endcolor, 4, 2));
//determine gradient-delta's
$stepR = (255-$EndcolorRGB['r'])/255.0;
$stepG = (255-$EndcolorRGB['g'])/255.0;
$stepB = (255-$EndcolorRGB['b'])/255.0;
//aColor contains the 256 gradations between endcolor(i=0) and white(i=255)
$aColor = array();
for ($i = 0; $i<=255; $i++){
$aColor[$i]['r'] = $EndcolorRGB['r'] + ($i*$stepR);
$aColor[$i]['g'] = $EndcolorRGB['g'] + ($i*$stepG);
$aColor[$i]['b'] = $EndcolorRGB['b'] + ($i*$stepB);
}
//for every color-index we now replace $gray-values for $aColor
for ($c = 0; $c < imagecolorstotal($im); $c++){
$currentColorRGB = imagecolorsforindex($im, $c);
$gray = $currentColorRGB['red'];//image is grayscale, so red,green and blue
// should be equal. We use this number as key of aColor
imagecolorset($im,$c,(int)$aColor[$gray]['r'], (int)$aColor[$gray]['g'], (int)$aColor[$gray]['b']);
}
}?>This function change colors of an image with ranges 0>100 for each primary color:
int ImageSelectiveColor (int im, int red, int green, int blue)
im is image pointer
red, green and blue are ranges 0->100
function ImageSelectiveColor($im,$red,$green,$blue)
{
for($i=0;$i<imagecolorstotal($im);$i++)
{
$col=ImageColorsForIndex($im,$i);
$red_set=$red/100*$col['red'];
$green_set=$green/100*$col['green'];
$blue_set=$blue/100*$col['blue'];
if($red_set>255)$red_set=255;
if($green_set>255)$green_set=255;
if($blue_set>255)$blue_set=255;
imagecolorset($im,$i,$red_set,$green_set,$blue_set);
}
return $im;
}Here is a function to turn an image into pure black and white
<?php
function imagepurebw( $img, $amount = 383 ) {
$total = imagecolorstotal( $img );
for ( $i = 0; $i < $total; $i++ ) {
$index = imagecolorsforindex( $img, $i );
array_pop( $index );
$color = ( array_sum( $index ) > $amount ) ? 255 : 0;
imagecolorset( $img, $i, $color, $color, $color );
}
}
?>here's a simple function to greyscale an image...
function imagecolorgrey( &$img ) {
for( $i=0; $i<imagecolorstotal( $img ); $i++ ) {
$c = ImageColorsForIndex( $img, $i );
$t = ($c["red"]+$c["green"]+$c["blue"])/3;
imagecolorset( $img, $i, $t, $t, $t );
}
}