PHP Doku:: Copy and merge part of an image - function.imagecopymerge.html

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GD- und Image-Funktionen

<<imagecopy

imagecopymergegray>>

imagecopymerge

(PHP 4 >= 4.0.1, PHP 5)

imagecopymergeCopy and merge part of an image

Beschreibung

bool imagecopymerge ( resource $dst_im , resource $src_im , int $dst_x , int $dst_y , int $src_x , int $src_y , int $src_w , int $src_h , int $pct )

Copy a part of src_im onto dst_im starting at the x,y coordinates src_x, src_y with a width of src_w and a height of src_h. The portion defined will be copied onto the x,y coordinates, dst_x and dst_y.

Parameter-Liste

dst_im

Destination image link resource.

src_im

Source image link resource.

dst_x

x-coordinate of destination point.

dst_y

y-coordinate of destination point.

src_x

x-coordinate of source point.

src_y

y-coordinate of source point.

src_w

Source width.

src_h

Source height.

pct

The two images will be merged according to pct which can range from 0 to 100. When pct = 0, no action is taken, when 100 this function behaves identically to imagecopy() for pallete images, while it implements alpha transparency for true colour images.

Rückgabewerte

Gibt bei Erfolg TRUE zurück. Im Fehlerfall wird FALSE zurückgegeben.

Beispiele

Beispiel #1 Merging two copies of the PHP.net logo with 75% transparency

<?php
// Create image instances
$dest imagecreatefromgif('php.gif');
$src imagecreatefromgif('php.gif');

// Copy and merge
imagecopymerge($dest$src1010001004775);

// Output and free from memory
header('Content-Type: image/gif');
imagegif($dest);

imagedestroy($dest);
imagedestroy($src);
?>


21 BenutzerBeiträge:
- Beiträge aktualisieren...
Fred
24.09.2010 20:39
TO merge two images with alpha - use a brush to draw a zero length line in the centre of the target image, using the src img as the brush img. The code probably explains it better:

<?php
$src
= imagecreatefromstring(file_get_contents("location of src"));
$dest = imagecreatefromstring(file_get_contents("location of dest"));

// Set the brush
imagesetbrush($dest, $src);
// Draw a couple of brushes, each overlaying each
imageline($dest, imagesx($dest) / 2, imagesy($dest) / 2, imagesx($dest) / 2, imagesy($dest) / 2, IMG_COLOR_BRUSHED);

header('Content-Type: image/png');
imagepng($dest);
?>

This is simple and has reasonable performance.
Sina Salek
9.08.2009 10:26
I've just checked PHP's issue tracker and a core developer says that this function was never meant to support alpha channel! and they refused to commit the provided patch! so ridicules
Anyway i tried rodrigo's workaround and it worked quite well, thanks rodrigo for sharing it.
I came up with another idea which is much faster than his solution, (it may need a little bit more memory)

Hope it helps someone.

<?php
/**
 * PNG ALPHA CHANNEL SUPPORT for imagecopymerge();
 * by Sina Salek
 *
 * Bugfix by Ralph Voigt (bug which causes it
 * to work only for $src_x = $src_y = 0.
 * Also, inverting opacity is not necessary.)
 * 08-JAN-2011
 *
 **/
   
function imagecopymerge_alpha($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $pct){
       
// creating a cut resource
       
$cut = imagecreatetruecolor($src_w, $src_h);

       
// copying relevant section from background to the cut resource
       
imagecopy($cut, $dst_im, 0, 0, $dst_x, $dst_y, $src_w, $src_h);
       
       
// copying relevant section from watermark to the cut resource
       
imagecopy($cut, $src_im, 0, 0, $src_x, $src_y, $src_w, $src_h);
       
       
// insert cut resource to destination image
       
imagecopymerge($dst_im, $cut, $dst_x, $dst_y, 0, 0, $src_w, $src_h, $pct);
    }

?>
santin1991[at]gmail[dot]com
24.04.2009 1:16
Add logo on image script.
<?php
/**
 * Put logo on low right jpeg image
 * used stefan's script for position
 **/
$logo_file = "logo.png";
$image_file = "img.jpg";
$targetfile = "img2.jpg";
$photo = imagecreatefromjpeg($image_file);
$fotoW = imagesx($photo);
$fotoH = imagesy($photo);
$logoImage = imagecreatefrompng($logo_file);
$logoW = imagesx($logoImage);
$logoH = imagesy($logoImage);
$photoFrame = imagecreatetruecolor($fotoW,$fotoH);
$dest_x = $fotoW - $logoW;
$dest_y = $fotoH - $logoH;
imagecopyresampled($photoFrame, $photo, 0, 0, 0, 0, $fotoW, $fotoH, $fotoW, $fotoH);
imagecopy($photoFrame, $logoImage, $dest_x, $dest_y, 0, 0, $logoW, $logoH);
imagejpeg($photoFrame, $targetfile); 
echo
'<img src="'.$targetfile.'" />';
?>
rodrigo dot polo at gmail dot com
25.01.2009 11:52
<?php
/**
 * PNG ALPHA CHANNEL SUPPORT for imagecopymerge();
 * This is a function like imagecopymerge but it handle alpha channel well!!!
 **/

// A fix to get a function like imagecopymerge WITH ALPHA SUPPORT
// Main script by aiden dot mail at freemail dot hu
// Transformed to imagecopymerge_alpha() by rodrigo dot polo at gmail dot com
function imagecopymerge_alpha($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h, $pct){
    if(!isset(
$pct)){
        return
false;
    }
   
$pct /= 100;
   
// Get image width and height
   
$w = imagesx( $src_im );
   
$h = imagesy( $src_im );
   
// Turn alpha blending off
   
imagealphablending( $src_im, false );
   
// Find the most opaque pixel in the image (the one with the smallest alpha value)
   
$minalpha = 127;
    for(
$x = 0; $x < $w; $x++ )
    for(
$y = 0; $y < $h; $y++ ){
       
$alpha = ( imagecolorat( $src_im, $x, $y ) >> 24 ) & 0xFF;
        if(
$alpha < $minalpha ){
           
$minalpha = $alpha;
        }
    }
   
//loop through image pixels and modify alpha for each
   
for( $x = 0; $x < $w; $x++ ){
        for(
$y = 0; $y < $h; $y++ ){
           
//get current alpha value (represents the TANSPARENCY!)
           
$colorxy = imagecolorat( $src_im, $x, $y );
           
$alpha = ( $colorxy >> 24 ) & 0xFF;
           
//calculate new alpha
           
if( $minalpha !== 127 ){
               
$alpha = 127 + 127 * $pct * ( $alpha - 127 ) / ( 127 - $minalpha );
            } else {
               
$alpha += 127 * $pct;
            }
           
//get the color index with new alpha
           
$alphacolorxy = imagecolorallocatealpha( $src_im, ( $colorxy >> 16 ) & 0xFF, ( $colorxy >> 8 ) & 0xFF, $colorxy & 0xFF, $alpha );
           
//set pixel with the new color + opacity
           
if( !imagesetpixel( $src_im, $x, $y, $alphacolorxy ) ){
                return
false;
            }
        }
    }
   
// The image copy
   
imagecopy($dst_im, $src_im, $dst_x, $dst_y, $src_x, $src_y, $src_w, $src_h);
}

// USAGE EXAMPLE:
$img_a = imagecreatefrompng('image1.png');
$img_b = imagecreatefrompng('wm2.png');

// SAME COMMANDS:
imagecopymerge_alpha($img_a, $img_b, 10, 10, 0, 0, imagesx($img_b), imagesy($img_b),50);

// OUTPUT IMAGE:
header("Content-Type: image/png");
imagesavealpha($img_a, true);
imagepng($img_a, NULL);
?>
gigitrix
3.09.2008 15:01
Some highly amusing stuff: This code appears normal and is a way to cut out slices of an image randomly.

<?php
header
("Content-Type: image/jpeg");
$width=837;
$height=771;
$origim = imagecreatefromjpeg("theimage.jpeg"); /* Attempt to open */
$imagetodisplay=imagecreate($width, $height);

for(
$i=0;$i<=100;$i++)
{
$xPos=rand(0,$width-9);
$yPos=rand(0,$height-9);
imagecopy($imagetodisplay, $origim, $xPos, $yPos , $xPos, $yPos , 10  , 10);
}

imagejpeg($imagetodisplay);
imagedestroy($imagetodisplay);
imagedestroy($origim);
?>

Try running this however and an omitted detail adds to the fun. Since the first colour that is defined is taken to be the background colour, we have a random colour selected from $origim as the background colour for $imagetodisplay, but this random colour is weighted according to the background image. It was a surprise (I thought the bg would be black) but I am now keeping it as it looks good.
eric
10.07.2007 22:57
you need to stream the image out after processing ...something like

<?php

// All of your existing code

imagepng($image);

?>
Al
9.07.2007 16:23
Check your header... He is false...

<?php
header
("Content-Type: image/png");
?>
jay at zylex dot net dot nz
25.02.2007 0:45
Hi
i wrote this script to add a watermark image into the bottom right a larger image. Its very basic i know but its all i need for now. It also is an easy function for noobs to grasp. It just takes an two image types as arguments

for example
$image = imagecreatefromjpeg("FILELOCATION");
$insert = imagecreatefrompng("WATERMARKFILELOCATION");
$image = image_overlap($image, $insert);

function image_overlap($background, $foreground){
   $insertWidth = imagesx($foreground);
   $insertHeight = imagesy($foreground);

   $imageWidth = imagesx($background);
   $imageHeight = imagesy($background);

   $overlapX = $imageWidth-$insertWidth-5;
   $overlapY = $imageHeight-$insertHeight-5;
               imagecolortransparent($foreground,
imagecolorat($foreground,0,0));                imagecopymerge($background,$foreground,
$overlapX,$overlapY,0,0,$insertWidth,$insertHeight,100);   return $background;
    }

It doesnt smooth the edges between the two images but it works easily.
jylyn at hotmail dot com
22.02.2006 10:49
A few corrections to the code supplied by nick at prient:

$iTemplate should be $iBackground
$iWorking should be $iSource

After fixing those two I found the script really useful, thanks!
nick at prient dot co dot uk
1.11.2005 23:15
Task: Rotate a large image, then reduce it in size and place it on a small background (i.e. as an Inset).

Problem: If you resize the image first, the rotation becomes hugely aliased...  So, it makes sense to rotate it first, then shrink it.
Unfortunately, when you resample the image, you lose the background color (at least, some of it may change), so you can no longer set transparancy as you require.  If instead you resize the image (rather than resample), again, the aliasing looks bad.

Solution:  Resize the background - make it bigger.  Then add the original (large) inset, and resize the whole thing back to normal.

<?php
/* We will shrink the inset to 25% */
$resizePercentage = 0.25;

/* Load a source image and a background */
$iSource = ImageCreateFromJpeg($source_file);
$iBackground = ImageCreateFromJpeg($background_file);

/* Do something here, such a rotate, skew etc */
...
/* Assume $iSource is still the image we want to insert onto the background */

/* Set the background color to be transparent */
$cBackground = ImageColorClosest($iSource, 255, 0, 255);
ImageColorTransparent($iSource, $cBackground);

/* Resize the background - make it huge */
$iBackground = ImageResize($iTemplate, ImageSX($iBackground ) / $resizePercentage, ImageSY($iBackground ) / $resizePercentage);
/* Place the image on the background - all full size, so no aliasing issues */
ImageCopyMerge($iBackground , $iSource,
    ((
ImageSX($iBackground ) - ImageSX($iSource)) / 2),
    ((
ImageSY($iBackground ) - ImageSY($iSource)) / 2) - 25, 0, 0, ImageSX($iWorking), ImageSY($iSource), 100);
/* Shrink the combined image... no issues with transparancy! */
$iBackground = ImageResize($iTemplate, ImageSX($iBackground ) * $resizePercentage, ImageSY($iBackground ) * $resizePercentage);

/* Output the image as a PNG */
header("Content-Type: image/png");
ImagePng($iBackground);
exit();

function
ImageResize($pImage, $t_width, $t_height) {
 
// Target image
 
$iCanvas = @ImageCreateTrueColor($t_width, $t_height);
 
// Source dimensions
 
$s_width = ImageSX($pImage);
 
$s_height = ImageSY($pImage);
 
// Copy image
 
ImageCopyResampled($iCanvas, $pImage, 0, 0, 0, 0, $t_width, $t_height, $s_width, $s_height);
 
// Return image
 
return $iCanvas;
}
?>
Ascent [at] WebAQ.com
24.05.2005 11:41
First you need make 0~9 gif format images and background image.

<?php
/*
make random image number check
20050524 by ascent WebAQ.com
*/

$rands = rand(1000,9999);

session_start();
$_SESSION['random_image_number_check'] = $rands;

$bg = './random_image_bg.jpg';
$numimgp = './random_image_number_%d.gif';

$numimg1 = sprintf($numimgp,substr($rands,0,1));
$numimg2 = sprintf($numimgp,substr($rands,1,1));
$numimg3 = sprintf($numimgp,substr($rands,2,1));
$numimg4 = sprintf($numimgp,substr($rands,3,1));
$ys1 = rand(-4,4);
$ys2 = rand(-4,4);
$ys3 = rand(-4,4);
$ys4 = rand(-4,4);

$bgImg = imageCreateFromJPEG($bg);
$nmImg1 = imageCreateFromGIF($numimg1);
$nmImg2 = imageCreateFromGIF($numimg2);
$nmImg3 = imageCreateFromGIF($numimg3);
$nmImg4 = imageCreateFromGIF($numimg4);
imageCopyMerge($bgImg, $nmImg1, 10, $ys1, 0, 0, 20, 30, 50);
imageCopyMerge($bgImg, $nmImg2, 30, $ys2, 0, 0, 20, 30, 50);
imageCopyMerge($bgImg, $nmImg3, 50, $ys3, 0, 0, 20, 30, 50);
imageCopyMerge($bgImg, $nmImg4, 70, $ys4, 0, 0, 20, 30, 50);
header("Content-type: image/jpg");
ImageJPEG($bgImg,"",100);
imagedestroy($bgImg);
imagedestroy($nmImg1);
imagedestroy($nmImg2);
imagedestroy($nmImg3);
imagedestroy($nmImg4);
?>

enjoy!
Steve
23.05.2005 20:03
Building upon backglancer's and stefan's posts below, the following script will lay a 24-bit PNG watermark over any image.

To prepare a 24-bit watermark, I recommend creating a white logo or text over a transparent background in Photoshop.  Save this as a 24-bit PNG via 'Save for the Web...'.  Be sure to set the transparency of the logo layer in Photoshop itself.  30-40% is a good setting.

Once the assets are prepared, throw the full or relative server paths at the watermark function below:

/******************************************************************/

function watermark($sourcefile, $watermarkfile) {
 
    #
    # $sourcefile = Filename of the picture to be watermarked.
    # $watermarkfile = Filename of the 24-bit PNG watermark file.
    #
   
    //Get the resource ids of the pictures
    $watermarkfile_id = imagecreatefrompng($watermarkfile);
   
    imageAlphaBlending($watermarkfile_id, false);
    imageSaveAlpha($watermarkfile_id, true);

    $fileType = strtolower(substr($sourcefile, strlen($sourcefile)-3));

    switch($fileType) {
        case('gif'):
            $sourcefile_id = imagecreatefromgif($sourcefile);
            break;
           
        case('png'):
            $sourcefile_id = imagecreatefrompng($sourcefile);
            break;
           
        default:
            $sourcefile_id = imagecreatefromjpeg($sourcefile);
    }

    //Get the sizes of both pix  
  $sourcefile_width=imageSX($sourcefile_id);
  $sourcefile_height=imageSY($sourcefile_id);
  $watermarkfile_width=imageSX($watermarkfile_id);
  $watermarkfile_height=imageSY($watermarkfile_id);

    $dest_x = ( $sourcefile_width / 2 ) - ( $watermarkfile_width / 2 );
    $dest_y = ( $sourcefile_height / 2 ) - ( $watermarkfile_height / 2 );
   
    // if a gif, we have to upsample it to a truecolor image
    if($fileType == 'gif') {
        // create an empty truecolor container
        $tempimage = imagecreatetruecolor($sourcefile_width,
                                                                            $sourcefile_height);
       
        // copy the 8-bit gif into the truecolor image
        imagecopy($tempimage, $sourcefile_id, 0, 0, 0, 0,
                            $sourcefile_width, $sourcefile_height);
       
        // copy the source_id int
        $sourcefile_id = $tempimage;
    }

    imagecopy($sourcefile_id, $watermarkfile_id, $dest_x, $dest_y, 0, 0,
                        $watermarkfile_width, $watermarkfile_height);

    //Create a jpeg out of the modified picture
    switch($fileType) {
   
        // remember we don't need gif any more, so we use only png or jpeg.
        // See the upsaple code immediately above to see how we handle gifs
        case('png'):
            header("Content-type: image/png");
            imagepng ($sourcefile_id);
            break;
           
        default:
            header("Content-type: image/jpg");
            imagejpeg ($sourcefile_id);
    }          
 
    imagedestroy($sourcefile_id);
    imagedestroy($watermarkfile_id);
   
}
backglancer in the hotmail
17.05.2005 11:44
I was about to kill myself....
any one of you trying to merge a SEMI transparent png...
use imagecopy   :)
<?
$flag
= imagecreatefrompng('flags/images/flagWhiteFill.png');
$mask = imagecreatefrompng('flags/images/flag_transparent.png');

imagealphablending($flag, 1);
imagealphablending($mask, 1);

imagecopy($flag, $mask, 0,0,0,0,25,43);

Header("Content-type: image/jpeg");
imagepng($flag);
?>

ImageSaveAlpha(resource, bool);   made the transparent color - not transparent... dunno why :)
barbarina_sv at libero dot it
17.05.2005 10:55
I needed to draw a "pointer" image over a map, but had some problems with png image transparency.
So I created a png image with white background (not transparent) and merged it on my map, after defining white color as transparent:

<?php

$src_file
= 'source.jpg';
list(
$src_w, $src_h, $src_t, $src_a) = getimagesize($src_file);

$ptr_file = 'pointer.png'; // must have no transparency, but white background
list($ptr_w, $ptr_h, $ptr_t, $ptr_a) = getimagesize($ptr_file);

// destination image dimensions:
$dst_w = 400;
$dst_h = 200;

// pointer position:
$ptr_x = 195;
$ptr_y = 70;

$srcImage = imageCreateFromJpeg($src_file) or die ('failed imageCreateFromJpg');
$dstImage = imageCreateTrueColor($dst_w, $dst_h) or die ('failed imageCreateTrueColor');

imageCopyResampled($dstImage, $srcImage, 0, 0, 0, 0, $dst_w, $dst_h, $src_w, $src_h) or die ('failed imageCopyResampled');

$ptrImage = imageCreateFromPng($ptr_file) or die ('failed imageCreateFromPng');

$ptr_white = imageColorAllocate($ptrImage,255,255,255);
imageColorTransparent($ptrImage,$ptr_white);

imageCopyMerge($dstImage, $ptrImage, $ptr_x, $ptr_y, 0, 0, $ptr_w, $ptr_h, 100) or die ('failed imageCopyMerge');

imageJpeg($dstImage,'',100) or die ('failed imageJpeg');

imageDestroy($srcImage) or die ('failed imageDestroy(1)');
imageDestroy($dstImage) or die ('failed imageDestroy(2)');
imageDestroy($ptrImage) or die ('failed imageDestroy(3)');

?>
ingrid
4.04.2005 23:16
I found on the internet about a thousand copies of this "imageCopyMerge" script of Stefan.

Most of them had a  copyright notice of the copyist added, but none of them had added what a starting user of PHP scripting really needs: The lines to be used in a HTML page, where the result of the script will be visible:

<?php
$sourcefile
= "ORIGFILE.jpg";
$insertfile = "watermark.jpg";
$targetfile = "foto.jpg";
$transition = 30;
$pos=7;
require(
"watermark.php");
mergePix($sourcefile, $insertfile, $targetfile, $pos, $transition);
echo
"<img src=\"$targetfile\">";
?>

I was so lucky to get these lines from someone on the internet, after I posted my question all over the world.
Most other people that replied, referred to the bookstore. But I had first read halve the (this) PHP manual, and had not found it.

Just a suggestion, but I know it will help many people getting started with PHP: When you put your scripts here, why not add those few lines needed to incorporate it into a HTML page?
jtacon at php dot net
14.12.2004 14:36
This example shows how to use imageCopyMerge to create a water mark function with four random positions (the corners).

<?php
function waterMark($fileInHD, $wmFile, $transparency = 50, $jpegQuality = 90, $margin = 5) {

 
$wmImg   = imageCreateFromGIF($wmFile);
 
$jpegImg = imageCreateFromJPEG($fileInHD);

 
// Water mark random position
 
$wmX = (bool)rand(0,1) ? $margin : (imageSX($jpegImg) - imageSX($wmImg)) - $margin;
 
$wmY = (bool)rand(0,1) ? $margin : (imageSY($jpegImg) - imageSY($wmImg)) - $margin;

 
// Water mark process
 
imageCopyMerge($jpegImg, $wmImg, $wmX, $wmY, 0, 0, imageSX($wmImg), imageSY($wmImg), $transparency);

 
// Overwriting image
 
ImageJPEG($jpegImg, $fileInHD, $jpegQuality);
}

waterMark('myImage.jpg','waterMark.gif');

?>

HTH.

Javier Tacón.
claudio dot gaetani at gdldesign dot it
9.05.2004 20:04
This function is intended to serve as an example for the "imageCopyMerge"-"ImageCopyResized", "ImageColorTransparent" functions.
I hope it will help.
This function pick an image, square cut it resampled at the size requested and finishing merge the result with another one to obtain a circular image result. I have a problem to obtain an thumbnail that respect the colors and at the same time where cutted in a circular form, I hope this solution can gives you a clue to obtain a free form images, I use this one also to create multicutted images.

<?php
$generalsrc
="$image"; //the image to resample, resize and iconaize
$final_thumbwidth ="125";
$final_thumbheight ="125";

$abc = imagecreatefromjpeg("$generalsrc");
$def = imagecreatetruecolor($final_thumbwidth, $final_thumbheight);
$src_mx = round((imagesx($abc) / 2)-"0.1"); // middle x point of the image
$src_my = round((imagesy($abc) / 2)-"0.1"); // middle y point of the image
$src_x = ($src_mx * 2);
$src_y = ($src_my * 2);
$src_sq = ($src_x >= $src_y)?$src_y:$src_x; //used to define the best size for a square cut of the image
$pl = ($src_x >= $src_y)?"1":"2"; //define if the image is portait or landscape
$strt_pntx = ($pl=="1")?round(($src_my / 2)-"0. 1"):"0"//defines the x start point
$strt_pnty = ($pl=="2")?round(($src_mx / 2)-"0. 1"):"0"//defines the y start point

imagecopyresized($def, $abc, 0, 0, $strt_pntx, $strt_pnty, $final_thumbwidth, $final_thumbheight, $src_sq, $src_sq);

$overlay_img = imagecreatefromPNG("circle_125.png"); //NOTE use png for this
$src_w = "ImageSX($overlay_img)";
$src_h  = "ImageSY($overlay_img)";

$can_img = imagecreatetruecolor($src_w, $src_h);

$black = ImageColorAllocate ($overlay_img, 0, 0, 0);

ImageColorTransparent($overlay_img , $black);

imagecopy($can_img, $def, 0,0,0,0, $src_w, $src_h);
imagecopymerge($can_img, $overlay_img , 0,0,0,0, ImageSX($overlay_img), ImageSY($overlay_img),100); //Imagecopy won't work, you must used imagecopymerge

ImageJPEG($can_img,"merge_$generalsrc",100);

imagedestroy($overlay_img);
imagedestroy($can_img);
ImageDestroy($abc);
ImageDestroy($def);

print
"<HTML><HEAD><TITLE>test</TITLE></HEAD><BODY>
original:<hr><img src=\"
$generalsrc\" width=\"300\"><br><br><br>new:<hr><img src=\"merge_$generalsrc\">
<br>width =
$src_x
<br>height =
$src_y
<br>mdlw =
$src_mx
<br>mdlh =
$src_my
<br>sqr =
$src_sq
<br>pl =
$pl
<br>start point x =
$strt_pntx
<br>start point y =
$strt_pnty
</BODY></HTML>"
;
?>
bjorn AT smokingmedia DOT com
26.05.2003 20:10
in addition to stefan's posting:

i found that if you use imagecopymerge with png-24 files with an alpha channel, it doesn't work use imagecopy instead.
it seems that imagecopymerge doesn't respect the alpha channel the way it should (a bug??).

some sample code here to place an image (image.png) on a backgroundcolor or backgroundimage.

<?php

$im
= "image.png";
$bg = "ffddee";     // hex representation of the color (i.e. #ffffff for white)
$out = "png";       // or "jpg" for jpg file output
// $backgroundfile = "";  // optional backgroundfile if you don't want to use a color

//
// function to convert hex colorcode to decimal
//

function colordecode($hex){

  
$code[r] = hexdec(substr($hex, 0 ,2));
  
$code[g] = hexdec(substr($hex, 2 ,2));
  
$code[b] = hexdec(substr($hex, 4 ,2));

   return
$code;

}
// end func colordecode

// create the resource id
$image_id = imageCreateFromPNG($im);

// get image size
$im_X = ImageSX($image_id);
$im_Y = ImageSY($image_id);

// create a truecolor background image of the right size
// or use a background image like this
// $backgroundimage = imageCreateFromPNG($backgroundfile);
$backgroundimage = imagecreatetruecolor($im_X, $im_Y);

// get the desired backgroundcolor:
// don't use this if you want to use a background image
$code = colordecode($bg);
$backgroundcolor = ImageColorAllocate($backgroundimage, $code[r], $code[g], $code[b]);
ImageFilledRectangle($backgroundimage, 0, 0, $im_X, $im_Y, $backgroundcolor);

// merge the two together with alphablending on!
ImageAlphaBlending($backgroundimage, true);
imagecopy($backgroundimage, $image_id, 0, 0, 0, 0, $im_X, $im_Y);

// output the image:
if($output == "jpg"){
  
Header( "Content-type: image/jpeg");
  
ImageJPEG($backgroundimage);
   }
   else{
      
Header( "Content-type: image/png");
      
ImagePNG($backgroundimage);
       }

// destroy the memory
ImageDestroy($backgroundimage);
ImageDestroy($image_id);
?>
feisty at feistyenterprises dot com
6.11.2002 21:15
Yep, that worked a charm.

Since imageCopyMergeGray() is identical, it works just as well for that.

If you want to convert an image to greyscale, use imageCopyMergeGray() with the same image as source and destination, set the pict to 0, et voila!
jonny at sanriowasteland dot net
29.09.2002 14:36
If you need to merge 2 png's (or  presumably 2 gifs) with different color palettes, I have found this is the function to use.  Just set pct to 99, and you are rocking.  With pct set to 100, or imagecopy for that matter, the palette seems to go wonky.  (It probably just uses the palette of the source image. but don't quote me on that).
stefan dot wehowsky at profilschmiede dot de
26.07.2001 18:32
This function is intended to serve as an example for the "imageCopyMerge"-function.
I hope it will help some of the less experienced php-coders here.
I wrote it to mark objects of a real estate broker as "sold" by copying the "sold"-picture right into the picture of the house.

<?php

//$sourcefile = Filename of the picture into that $insertfile will be inserted.
//$insertfile = Filename of the picture that is to be inserted into $sourcefile.
//$targetfile = Filename of the modified picture.
//$transition = Intensity of the transition (in percent)
//$pos          = Position where $insertfile will be inserted in $sourcefile
//                0 = middle
//                1 = top left
//                2 = top right
//                3 = bottom right
//                4 = bottom left
//                5 = top middle
//                6 = middle right
//                7 = bottom middle
//                8 = middle left
//
//
function mergePix($sourcefile,$insertfile, $targetfile, $pos=0,$transition=50)
{
   
//Get the resource id´s of the pictures
   
$insertfile_id = imageCreateFromJPEG($insertfile);
   
$sourcefile_id = imageCreateFromJPEG($sourcefile);

//Get the sizes of both pix   
   
$sourcefile_width=imageSX($sourcefile_id);
   
$sourcefile_height=imageSY($sourcefile_id);
   
$insertfile_width=imageSX($insertfile_id);
   
$insertfile_height=imageSY($insertfile_id);

//middle
   
if( $pos == 0 )
    {
       
$dest_x = ( $sourcefile_width / 2 ) - ( $insertfile_width / 2 );
       
$dest_y = ( $sourcefile_height / 2 ) - ( $insertfile_height / 2 );
    }

//top left
   
if( $pos == 1 )
    {
       
$dest_x = 0;
       
$dest_y = 0;
    }

//top right
   
if( $pos == 2 )
    {
       
$dest_x = $sourcefile_width - $insertfile_width;
       
$dest_y = 0;
    }

//bottom right
   
if( $pos == 3 )
    {
       
$dest_x = $sourcefile_width - $insertfile_width;
       
$dest_y = $sourcefile_height - $insertfile_height;
    }

//bottom left   
   
if( $pos == 4 )
    {
       
$dest_x = 0;
       
$dest_y = $sourcefile_height - $insertfile_height;
    }

//top middle
   
if( $pos == 5 )
    {
       
$dest_x = ( ( $sourcefile_width - $insertfile_width ) / 2 );
       
$dest_y = 0;
    }

//middle right
   
if( $pos == 6 )
    {
       
$dest_x = $sourcefile_width - $insertfile_width;
       
$dest_y = ( $sourcefile_height / 2 ) - ( $insertfile_height / 2 );
    }
       
//bottom middle   
   
if( $pos == 7 )
    {
       
$dest_x = ( ( $sourcefile_width - $insertfile_width ) / 2 );
       
$dest_y = $sourcefile_height - $insertfile_height;
    }

//middle left
   
if( $pos == 8 )
    {
       
$dest_x = 0;
       
$dest_y = ( $sourcefile_height / 2 ) - ( $insertfile_height / 2 );
    }
   
//The main thing : merge the two pix   
   
imageCopyMerge($sourcefile_id, $insertfile_id,$dest_x,$dest_y,0,0,$insertfile_width,$insertfile_height,$transition);

//Create a jpeg out of the modified picture
   
imagejpeg ($sourcefile_id,"$targetfile");
   
}



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