imagecolorset
(PHP 4, PHP 5)
imagecolorset — Set the color for the specified palette index
Description
void imagecolorset
( resource
$image
, int $index
, int $red
, int $green
, int $blue
[, int $alpha = 0
] )This sets the specified index in the palette to the specified color. This is useful for creating flood-fill-like effects in palleted images without the overhead of performing the actual flood-fill.
Parameters
-
image -
An image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
-
index -
An index in the palette.
-
red -
Value of red component.
-
green -
Value of green component.
-
blue -
Value of blue component.
-
alpha -
Value of alpha component.
Return Values
No value is returned.
Changelog
| Version | Description |
|---|---|
| 5.4.0 |
The alpha parameter was added.
|
Examples
Example #1 imagecolorset() example
<?php
// Create a 300x100 image
$im = imagecreate(300, 100);
// Set the background to be red
imagecolorallocate($im, 255, 0, 0);
// Get the color index for the background
$bg = imagecolorat($im, 0, 0);
// Set the backgrund to be blue
imagecolorset($im, $bg, 0, 0, 255);
// Output the image to the browser
header('Content-Type: image/png');
imagepng($im);
imagedestroy($im);
?>
- PHP Руководство
- Функции по категориям
- Индекс функций
- Справочник функций
- Обработка и генерация изображений
- Обработка изображений и GD
- gd_info
- getimagesize
- getimagesizefromstring
- image_type_to_extension
- image_type_to_mime_type
- image2wbmp
- imageaffine
- imageaffinematrixconcat
- imageaffinematrixget
- imagealphablending
- imageantialias
- imagearc
- imagechar
- imagecharup
- imagecolorallocate
- imagecolorallocatealpha
- imagecolorat
- imagecolorclosest
- imagecolorclosestalpha
- imagecolorclosesthwb
- imagecolordeallocate
- imagecolorexact
- imagecolorexactalpha
- imagecolormatch
- imagecolorresolve
- imagecolorresolvealpha
- imagecolorset
- imagecolorsforindex
- imagecolorstotal
- imagecolortransparent
- imageconvolution
- imagecopy
- imagecopymerge
- imagecopymergegray
- imagecopyresampled
- imagecopyresized
- imagecreate
- imagecreatefromgd2
- imagecreatefromgd2part
- imagecreatefromgd
- imagecreatefromgif
- imagecreatefromjpeg
- imagecreatefrompng
- imagecreatefromstring
- imagecreatefromwbmp
- imagecreatefromwebp
- imagecreatefromxbm
- imagecreatefromxpm
- imagecreatetruecolor
- imagecrop
- imagecropauto
- imagedashedline
- imagedestroy
- imageellipse
- imagefill
- imagefilledarc
- imagefilledellipse
- imagefilledpolygon
- imagefilledrectangle
- imagefilltoborder
- imagefilter
- imageflip
- imagefontheight
- imagefontwidth
- imageftbbox
- imagefttext
- imagegammacorrect
- imagegd2
- imagegd
- imagegif
- imagegrabscreen
- imagegrabwindow
- imageinterlace
- imageistruecolor
- imagejpeg
- imagelayereffect
- imageline
- imageloadfont
- imagepalettecopy
- imagepalettetotruecolor
- imagepng
- imagepolygon
- imagepsbbox
- imagepsencodefont
- imagepsextendfont
- imagepsfreefont
- imagepsloadfont
- imagepsslantfont
- imagepstext
- imagerectangle
- imagerotate
- imagesavealpha
- imagescale
- imagesetbrush
- imagesetinterpolation
- imagesetpixel
- imagesetstyle
- imagesetthickness
- imagesettile
- imagestring
- imagestringup
- imagesx
- imagesy
- imagetruecolortopalette
- imagettfbbox
- imagettftext
- imagetypes
- imagewbmp
- imagewebp
- imagexbm
- iptcembed
- iptcparse
- jpeg2wbmp
- png2wbmp
Коментарии
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 $im;
}
here's a simple function to greyscale an image...
function imagecolorgrey( &$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, $t );
}
}
here's a function to greyscale an image even from a truecolor source (jpeg or png).
slightly poor quality, but very fast...
function imagegreyscale(&$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, $i);
}
}
this is helpful if you would like to implement a color theme system in your website... try it out
Davide Candiloro Italy
function colorize ($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);
}
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);
}
}
?>
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, $color );
}
}
?>
I've been looking for a simple function which "colorizes" an image, without any success ... it looks like a lot of people mean something different with "colorizing" an image, because actually colorzing means multiplying the old color's grayscale with the new color. So a white pixel would become 100% of the colorize-to-color and a black pixel would stay black (I know I can't explain well ... I hope you understood, otherwise take a look at the example below the functions' code).
<?php
function image_colorize(&$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;
?>
Enjoy
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, $resB);
}
}
?>
I had the same problem as heavyraptor2 so i made this function...
<?php
function imagecolorize($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']);
}
}?>
If you are creating a palette image from scratch you have to use imagecolorallocate() for each index before you can use imagecolorset() on it.