imagecopy

add a note User Contributed Notes

C. Jansen
17-Aug-2006 02:02


While replying to a post in a support forum I noticed something odd about imagecopy(). The first snippet (should) create an image object, allocate a colour resource within that image, fill the background with the allocated colour and then copy another, cropped to fit, image onto it.



<?php

    // create a new image resource

    $temp = imagecreatetruecolor( $width, $height );

    $white = imagecolorallocate( $temp, 255, 255, 255 );



    //fill the background with white

    imagefill( $temp, 0, 0, $white );



    //copy the image into new a resource

    imagecopy($temp, $this->Image, 0, 0, $crop_top, $crop_left, $width, $height);

?>



But this produces a black background. I noticed taking away the imagefill() call yields the same results. The solution was to call imagefill() after the imagecopy(). Thinking linearly I would have guessed this to cover the previously copied image in white but it doesn't. I guess GD uses a layer system? Is this correct?



<?php

    // create a new image resource

    $temp = imagecreatetruecolor( $width, $height );

    $white = imagecolorallocate( $temp, 255, 255, 255 );



    // copy image into new resource

    imagecopy( $temp, $this->Image, 0, 0, $crop_top, $crop_left, $width, $height );

        

    //fill the background with white (not sure why it has to be in this order)

    imagefill( $temp, 0, 0, $white );

?>



I am using php 5.1.4 with the bundled GD (2.0.28)

administrador(ensaimada)sphoera(punt)com
03-May-2006 06:27


I've made a little function to wave images:



<?php

// So easy and nice!

function wave_region($img, $x, $y, $width, $height,$grade=5){

        for ($i=0;$i<$width;$i+=2){

            imagecopy($img,$img,

                $x+$i-2,$y+sin($i/10)*$grade,     //dest

                $x+$i,$y,             //src

                2,$height);

        }

    }

?>



More functions at http://www.sphoera.com

03-Apr-2006 01:21


Basic way to implement a "crop" feature : given an image (src), an offset (x, y) and a size (w, h).



crop.php :

<?php

$w=$_GET['w'];

$h=isset($_GET['h'])?$_GET['h']:$w;    // h est facultatif, =w par dfaut

$x=isset($_GET['x'])?$_GET['x']:0;    // x est facultatif, 0 par dfaut

$y=isset($_GET['y'])?$_GET['y']:0;    // y est facultatif, 0 par dfaut

$filename=$_GET['src'];

header('Content-type: image/jpg');

header('Content-Disposition: attachment; filename='.$src);

$image = imagecreatefromjpeg($filename); 

$crop = imagecreatetruecolor($w,$h);

imagecopy ( $crop, $image, 0, 0, $x, $y, $w, $h );

imagejpeg($crop);

?>



Call it like this :



<img src="crop.php?x=10&y=20&w=30&h=40&src=photo.jpg">

admin at cvxdes dot com
24-Feb-2006 12:26


I used this to watermark images. This is the function I wrote:



<?php

function watermark($url,$logo){

    $bwidth  = imagesx($url);

    $bheight = imagesy($url);

    $lwidth  = imagesx($logo);

    $lheight = imagesy($logo);

    $src_x = $bwidth - ($lwidth + 5);

    $src_y = $bheight - ($lheight + 5);

    ImageAlphaBlending($url, true);

    ImageCopy($url,$logo,$src_x,$src_y,0,0,$lwidth,$lheight);

}

?>



Usage:

<?php

//$current_image would be your image the watermark is overlayed onto. Make sure it's imagecreatefrom*** to work.

watermark($current_image,$watermark_image);

?>



Hope this helps someone.

relsqui at chiliahedron dot com
11-Feb-2006 04:28


Here's an alternative image-flipping function which is simpler than either of the ones I've seen in the docs here. It takes the source image and the mode (zero for horizontal, nonzero for vertical) and returns the flipped image.



<?php

function imageflip($image, $mode) {

        $w = imagesx($image);

        $h = imagesy($image);

        $flipped = imagecreate($w, $h);

        if ($mode) {

                for ($y = 0; $y < $h; $y++) {

                        imagecopy($flipped, $image, 0, $y, 0, $h - $y - 1, $w, 1);

                }

        } else {

                for ($x = 0; $x < $w; $x++) {

                        imagecopy($flipped, $image, $x, 0, $w - $x - 1, 0, 1, $h);

                }

        }

        return $flipped;

}

?>

designerkamal at gmail dot com
10-Feb-2006 03:38


Skewing images in PHP...

<?php

function Skew($src, $dest, $skew_val)

{

  $imgsrc = imagecreatefromgif($src);

  $width = imagesx($imgsrc);

  $height = imagesy($imgsrc);

  $imgdest = imagecreatetruecolor($width, $height+($height*$skew_val));

  $trans = imagecolorallocate($imgdest,0,0,0);

  $temp=0;

  for($x=0 ; $x<$width ; $x++)

   {

     for($y=0 ; $y<$height ; $y++) 

    {

        imagecopy($imgdest, $imgsrc, $x, $y+$temp, $x, $y, 1, 1);

      imagecolortransparent($imgdest,$trans);

        

    }

    $temp+=$skew_val;

   }

  imagepng($imgdest, $dest); 

  imagedestroy($imgsrc);

  imagedestroy($imgdest);

}

Skew("img.gif", "img2.png","1");

print "<img src='img.gif'>";

print "<br><br>";

print "<img src='img2.png'>";

?>

oryan at zareste dot com
15-Jan-2006 12:21


The source's palette is added to the destination's palette when merged, and when the destination already has 256 colors on it, the source image is altered to use those colors.  Truecolor images always take up 256 colors when merged with palette images, so if you're planning to add any additional images after doing so, you can use imagetruecolortopalette() on the truecolor image before merging it to reduce how much palette space it takes, and avoid losing colors in future merges to the same destination.  Example - imagetruecolortopalette($truecolorimg, FALSE, 128);

ragnar_40k at hotmail dot com
21-Nov-2005 07:17


Here a function to make holes into images:



// Set the alpha channel for a part of an image (it ignores the canvas alpha atm).

// $img_canvas - 32-bit true color image w/ alpha channel

// $img_mask - 8-bit gray scale image (white parts will be masked transparent in the canvas).

// This relies on the current pixel format:

// (high byte) -> (alpha channel} {red} {green} {blue} <- (low byte)

function mask($img_canvas, $img_mask, $dst_x, $dst_y)

{

   $old_blendmode = imagealphablending($img_canvas, FALSE);



   $width  = imagesx($img_mask);

   $heigth = imagesy($img_mask);



   $mask_x = 0;

   $x = $dst_y;

   while ($mask_x<$width)

   {

       $mask_y = 0;

       $y = $dst_y;

       while ($mask_y<$heigth)

       {

           imagesetpixel($img_canvas, $x, $y,

               ((imagecolorat($img_mask, $mask_x, $mask_y) >> 1) << 24) | (imagecolorat($img_canvas, $x, $y) & 0x00FFFFFF));



           ++$mask_y;

           ++$y;

       }

       ++$mask_x;

       ++$x;

   }



   imagealphablending($img_canvas, $old_blendmode);

}

johnny at netvor dot sk
21-Oct-2005 11:48


simple image combination srcipt, ie. if u want to create one  huuuge signature from more small ones



<?php

// config --

$src = array ("http://www.google.com/images/logo_sm.gif", "http://sk2.php.net/images/php.gif");    

$under = 0;    // combine images underneath or not?

// -- end of config



$imgBuf = array ();

$maxW=0; $maxH=0;

foreach ($src as $link)

{

    switch(substr ($link,strrpos ($link,".")+1))

    {

        case 'png':

            $iTmp = imagecreatefrompng($link);

            break;

        case 'gif':

            $iTmp = imagecreatefromgif($link);

            break;                

        case 'jpeg':            

        case 'jpg':

            $iTmp = imagecreatefromjpeg($link);

            break;                

    }



    if ($under)

    {

        $maxW=(imagesx($iTmp)>$maxW)?imagesx($iTmp):$maxW;

        $maxH+=imagesy($iTmp);

    }

    else

    {

        $maxW+=imagesx($iTmp);

        $maxH=(imagesy($iTmp)>$maxH)?imagesy($iTmp):$maxH;

    }



    array_push ($imgBuf,$iTmp);

}



$iOut = imagecreate ($maxW,$maxH) ;



$pos=0;

foreach ($imgBuf as $img)

{

    if ($under)

        imagecopy ($iOut,$img,0,$pos,0,0,imagesx($img),imagesy($img));

    else

        imagecopy ($iOut,$img,$pos,0,0,0,imagesx($img),imagesy($img));    

    $pos+= $under ? imagesy($img) : imagesx($img);

    imagedestroy ($img);

}



imagegif($iOut);

?>

php dot net at businet dot dk
21-Sep-2005 04:48


An little addon to Borszczuk's great function.



I've added the imagealphablending, so it supports transperency prette nice! It worked with me (only tested with PNG files).



I'm not sure if the imagesavealpha($imgdest, true); should be added, but it works fine without! No problems so far...



Thanks Borszczuk! Great job... 



The code with the addon:

<?php

  define("IMAGE_FLIP_HORIZONTAL",    1);

  define("IMAGE_FLIP_VERTICAL",    2);

  define("IMAGE_FLIP_BOTH",    3);



function ImageFlip($imgsrc, $type)

{

  $width = imagesx($imgsrc);

  $height = imagesy($imgsrc);



  $imgdest = imagecreatetruecolor($width, $height);

    ImageAlphaBlending($imgdest, false);



  switch( $type )

      {

      // mirror wzgl. osi

      case IMAGE_FLIP_HORIZONTAL:

          for( $y=0 ; $y<$height ; $y++ )

              imagecopy($imgdest, $imgsrc, 0, $height-$y-1, 0, $y, $width, 1);

          break;



      case IMAGE_FLIP_VERTICAL:

          for( $x=0 ; $x<$width ; $x++ )

              imagecopy($imgdest, $imgsrc, $width-$x-1, 0, $x, 0, 1, $height);

          break;



      case IMAGE_FLIP_BOTH:

          for( $x=0 ; $x<$width ; $x++ )

              imagecopy($imgdest, $imgsrc, $width-$x-1, 0, $x, 0, 1, $height);



          $rowBuffer = imagecreatetruecolor($width, 1);

          for( $y=0 ; $y<($height/2) ; $y++ )

              {

              imagecopy($rowBuffer, $imgdest  , 0, 0, 0, $height-$y-1, $width, 1);

              imagecopy($imgdest  , $imgdest  , 0, $height-$y-1, 0, $y, $width, 1);

              imagecopy($imgdest  , $rowBuffer, 0, $y, 0, 0, $width, 1);

              }



          imagedestroy( $rowBuffer );

          break;

      }



  return( $imgdest );

}

?>

sawaz
03-Jul-2005 07:45


Just a little function that allows you to change the foreground color of a transparent gif or png.

It's supposed to use only two-color images, becouse it convert all the colors to the specified one.



It works with .gif or .png as source, but writes only .png



function ColorReplace( $url )

{

    # The new color and its channels

    $NEW_COLOR = "#FF66FF";

    $r = 0+("0x".substr( $NEW_COLOR, 1, 2));

    $g = 0+("0x".substr( $NEW_COLOR, 3, 2));

    $b = 0+("0x".substr( $NEW_COLOR, 5, 2));



    # I read the kind of file from the extension

    $tmp = pathinfo($url);

    $extension =$tmp['extension'];

    if( $extension == 'png' ) $oldIm = @imagecreatefrompng( $url );

    elseif( $extension == 'gif' ) $oldIm = @imagecreatefromgif( $url );

    

    # I replace EACH color in the palette with the new one

    for( $i=0; $i < imagecolorstotal( $oldIm ); $i++ )

        imagecolorset( $oldIm, $i, $r,$g,$b );



    # Output the file in png format : each color is now NEW COLOR

    # but transparency is preserved !!

    header("Content-type: image/png");

    imagepng($oldIm);

    imagedestroy($oldIm);

}

cla [at] emeraldion [dot] it
22-May-2005 02:09


I've written a handy function to add rounded corners to an image. All you need is four images (the corners) with alpha transparency, so they need to be PNGs. This code can be eventually reused to add corners of any kind, not necessarily to round an image. Corners can be of different sizes, as the actual dimension is calculated for each one of them.



function roundedimage($source, $destination) {

  // Retrieve image informations

  $info = getimagesize($source);



  // Load image from file

  switch ($info['mime']) {

    case 'image/jpeg' :

      $image = imagecreatefromjpeg($source);

      break;

    case 'image/png' :

      $image = imagecreatefrompng($source);

      break;

    case 'image/gif' :

      $image = imagecreatefromgif($source);

      break;

    default:

      return FALSE;

  }

  

  // Set the alphablending to on

  imagealphablending($image, true);



  // Get the size of the image

  $image_w = imagesx($image);

  $image_h = imagesy($image);



  // Overlay left top corner

  $crnimage_nw = imagecreatefrompng("crn_nw.png");

  $crnimage_nw_w = imagesx($crnimage_nw);

  $crnimage_nw_h = imagesy($crnimage_nw);



  imagecopy($image, $crnimage_nw, 0, 0, 0, 0,

     $crnimage_nw_w, $crnimage_nw_h);



  // Overlay right top corner

  $crnimage_ne = imagecreatefrompng("crn_ne.png");

  $crnimage_ne_w = imagesx($crnimage_ne);

  $crnimage_ne_h = imagesy($crnimage_ne);



  imagecopy($image, $crnimage_ne, $image_w - $crnimage_ne_w,

     0, 0, 0, $crnimage_ne_w, $crnimage_ne_h);



  // Overlay left bottom corner

  $crnimage_sw = imagecreatefrompng("crn_sw.png");

  $crnimage_sw_w = imagesx($crnimage_sw);

  $crnimage_sw_h = imagesy($crnimage_sw);



  imagecopy($image, $crnimage_sw, 0, $image_h - $crnimage_sw_h,

     0, 0, $crnimage_sw_w, $crnimage_sw_h);



  // Overlay right bottom corner

  $crnimage_se = imagecreatefrompng("crn_se.png");

  $crnimage_se_w = imagesx($crnimage_se);

  $crnimage_se_h = imagesy($crnimage_se);



  imagecopy($image, $crnimage_se, $image_w - $crnimage_se_w,

     $image_h - $crnimage_se_h, 0, 0, $crnimage_se_w,

     $crnimage_se_h);



  // Output to the original format

  switch ($info['mime']) {

    case 'image/jpeg' :

      // Quality is set to 100%, maybe you can pass it via a param

      imagejpeg($image, $destination, 100);

      break;

    case 'image/png' :

      imagepng($image, $destination);

      break;

    case 'image/gif' :

      imagegif($image, $destination);

      break;

  }

  

  // Cleanup

  imagedestroy($image);

  imagedestroy($crnimage_nw);

  imagedestroy($crnimage_ne); 

  imagedestroy($crnimage_sw);

  imagedestroy($crnimage_se); 

}

slavo at polovnictvo-mn dot sk
20-Mar-2005 08:25


<?



// ****  counting of width - START

// possible rating 0..5

$max_rating = 5;

$image_rating_width = 52;    

$sirka_null = $image_rating_width / $max_rating * $_REQUEST['rating'];

// ****  counting of width sirky - END



$rating = imagecreatetruecolor(52,12);

$nula = imagecreatefromjpeg("0.jpg");

$full = imagecreatefromjpeg("5.jpg");

imagecopy($rating, $full, 0, 0 , 0, 0, $sirka_null, 12);

imagecopy($rating, $nula, $sirka_null, 0 , $sirka_null, 0, (52-$sirka_null+1), 12);

header("Content-Type: image/jpeg");

imagejpeg($rating);

imagedestroy($rating);

exit;

?>



0.jpg is equal in size to 5.jpg (foe example 5 stars in image)

0.jpg has 0 filled stars as rating

5.jpg has 5 filled stars as rating



my images have size 52x12 px



You just put them together by imagecopy function :-)

Borszczuk
05-Jan-2005 11:30


I got some comments to Mirror() function given below by lecoguic at yahoo dot fr. First, it's quite good example of coding-without-bit-of-design approach ;) Lecoguic loops by all pixels and copy it each by each. Not good. The *only* reason I could find this approach explained is that he wanted MIRROR_BOTH to be handled. So the code looks quite ok, but performs quite poor.  Below is much faster flipping function, blitting whole strips at once so it much more faster. $imgsrc is imagehandle. Function returns image handle to newly created flipped image. 



    define("IMAGE_FLIP_HORIZONTAL",    1);

    define("IMAGE_FLIP_VERTICAL",    2);

    define("IMAGE_FLIP_BOTH",    3);



function ImageFlip($imgsrc, $type)

{

    $width = imagesx($imgsrc);

    $height = imagesy($imgsrc);



    $imgdest = imagecreatetruecolor($width, $height);



    switch( $type )

        {

        // mirror wzgl. osi

        case IMAGE_FLIP_HORIZONTAL:

            for( $y=0 ; $y<$height ; $y++ )

                imagecopy($imgdest, $imgsrc, 0, $height-$y-1, 0, $y, $width, 1);

            break;



        case IMAGE_FLIP_VERTICAL:

            for( $x=0 ; $x<$width ; $x++ )

                imagecopy($imgdest, $imgsrc, $width-$x-1, 0, $x, 0, 1, $height);

            break;



        case IMAGE_FLIP_BOTH:

            for( $x=0 ; $x<$width ; $x++ )

                imagecopy($imgdest, $imgsrc, $width-$x-1, 0, $x, 0, 1, $height);



            $rowBuffer = imagecreatetruecolor($width, 1);

            for( $y=0 ; $y<($height/2) ; $y++ )

                {

                imagecopy($rowBuffer, $imgdest  , 0, 0, 0, $height-$y-1, $width, 1);

                imagecopy($imgdest  , $imgdest  , 0, $height-$y-1, 0, $y, $width, 1);

                imagecopy($imgdest  , $rowBuffer, 0, $y, 0, 0, $width, 1);

                }



            imagedestroy( $rowBuffer );

            break;

        }



    return( $imgdest );

}

cod at crescentofdarkness dot cjb dot net
21-Dec-2004 01:45


This function will put a truecolor png with transparency over a custom color backgorund.



The image will be gracefully blended with the background color using the alpha channel for each color.



In real world we'd just mix foreground and backgorund colors looking at their percentages (i.e. 20% of background + 80% of foreground)

Here we have to calculate this for each r, g and b value of each color, and we have to use 127 instead of 100, because alpha channel goes from 0 to 127.



Try it on a color-to-transparent gradient!



<?php

function pngcolorizealpha($file, $color) {

/*

Function:    pngcolorizealpha

Author:    CoD (cod at crescentofdarkness dot cjb dot net)

Summary:    Blends a truecolor png image with a coloured background using alpha channel



Input:

--------------------------

$file - string - path to the png image

$color- string - color in hex notation, without the #



Output:

--------------------------

a png image



*/



// first of all let's convert the background color

$background = array(

     'red'   => hexdec(substr($color,0,2)),

     'green' => hexdec(substr($color,2,2)),

     'blue'  => hexdec(substr($color,4,2))

);



$im1 = imagecreatefrompng($file) or die('Cannot Initialize new GD image stream');

$im2 = imagecreatetruecolor(imagesx($im1), imagesy($im1));

$col1 = imagecolorallocate($im2, $background['red'], $background['green'], $background['blue']);



imagefill($im2,0,0,$col1);



// for each color in the original png

for ($i=0; $i< imagecolorstotal($im1); $i++) {



    // find r,g,b and alpha value 

    $foreground = imagecolorsforindex($im1, $i);



    // blend fore and back colors using alpha value

    $r = (($foreground['red'] / 127) * (127 - $foreground['alpha'])) + (($background['red'] / 127)* $foreground['alpha']);

    $g = (($foreground['green'] / 127) * (127 - $foreground['alpha'])) + (($background['green'] / 127)* $foreground['alpha']);

    $b = (($foreground['blue'] / 127) * (127 - $foreground['alpha'])) + (($background['blue'] / 127)* $foreground['alpha']);



    // allocate this new color in the destination image

    imagecolorallocate($im2, $r,$g,$b);

}



imagecopy($im2, $im1, 0, 0, 0, 0, imagesx($im1), imagesy($im1));



header ("Content-type: image/png");

imagepng($im2);



imagedestroy($im1);

imagedestroy($im2);

}

?>

lecoguic at yahoo dot fr
30-May-2004 07:25


Here is a function to flip an image using imagecopy, just replace SRC_IMAGE and DEST_IMAGE with your own filename

(works only for jpg source image)



<?

define("MIRROR_HORIZONTAL", 1);

define("MIRROR_VERTICAL", 2);

define("MIRROR_BOTH", 3);



function Mirror($src, $dest, $type)

{

  $imgsrc = imagecreatefromjpeg($src);

  $width = imagesx($imgsrc);

  $height = imagesy($imgsrc);

  $imgdest = imagecreatetruecolor($width, $height);

  

  for ($x=0 ; $x<$width ; $x++)

    {

      for ($y=0 ; $y<$height ; $y++)

    {

      if ($type == MIRROR_HORIZONTAL) imagecopy($imgdest, $imgsrc, $width-$x-1, $y, $x, $y, 1, 1);

      if ($type == MIRROR_VERTICAL) imagecopy($imgdest, $imgsrc, $x, $height-$y-1, $x, $y, 1, 1);

      if ($type == MIRROR_BOTH) imagecopy($imgdest, $imgsrc, $width-$x-1, $height-$y-1, $x, $y, 1, 1);

    }

    }

  

  imagejpeg($imgdest, $dest);

  

  imagedestroy($imgsrc);

  imagedestroy($imgdest);

}



Mirror(SRC_IMAGE, DEST_IMAGE, MIRROR_HORIZONTAL);



print "<img src='SRC_IMAGE'>";

print "<br><br>";

print "<img src='DEST_IMAGE'>";

?>

RT
09-May-2004 06:09


Although the following function doesn't use imagecopy(), I thought it might help in related tasks. Please see the code comments for details of it's operation. I made this function to assist in creating images using multiple "layers". For example if you wanted to dynamically create a logo image with seperate colors for say the logo itself and a glow around the logo, these steps would be followed:



-Using an image editor (like Photoshop), create a png-24 image with just the logo on a transparent background. The logo can be any color or multiple colors, but the final image created by this function will be of a single color.



-Create a similar image with just the glow (no logo)



-Create a background image



-Apply this colorize() function to the logo image and the glow image with your desired color for each.



-You can now use imagecopy() to merge all three into a single image ready for a browser.



Here's the code



<?php



/*======Colorize=====

(requires GD 2.0.1 or greater)

This function requires the following arguments:

 $src_path = A string representing the relative path to the src image. Ex: "images/myimage.png". This

    image must be a png-24 with an alpha channel.

 $dest_path = A string representing the relative path to the image to be created.

 $hex_color = A string representing a color in html format, including the # sign. Ex: "#D2E5FF"

 

This function examines the transparency of the source image, pixel by pixel, and creates a new

one-color image with this same "transparency map".

====================*/



function colorize($src_path, $dest_path, $hex_color) {

    

    //get the png-24 image - it must have an alpha channel for this funciton to be effective

    $src = imagecreatefrompng($src_path);

    

    //get width

    $w = imagesx($src);

    

    //get height

    $h = imagesy($src);

    

    //create same size destination image

    $dest = imagecreatetruecolor($w, $h);

    

    //this must be set to false in order to be able to overwright the defualt black pixels of the background with our new 

    //transparent pixels. Otherwise our new pixel would just be applied on top of the black.

    imagealphablending($dest, false);

    

    //get decimal components of the passed hex color

    $red = hexdec(substr($hex_color, 1, 2));

    $green = hexdec(substr($hex_color, 3, 2));

    $blue = hexdec(substr($hex_color, 5, 2));

        

    for ($i = 0; $i < $h; $i++) { //this loop traverses each row in the image

        for ($j = 0; $j < $w; $j++) { //this loop traverses each pixel of each row

        

            //get the color & alpha info of the current pixel

            $retrieved_color = imagecolorat($src, $j, $i);

            

            //put this info into an array

            $rgba_array = imagecolorsforindex($src, $retrieved_color);

            

            //get the transparency of the pixel as a number from 0 (opaque) to 127 (transparent)

            $alpha = $rgba_array['alpha'];

            

            //allocate the color to paint. Note that we may continue to overwright this color since our image is not palleted

            $color_to_paint = imagecolorallocatealpha($dest, $red, $green, $blue, $alpha);

            

            //paint the pixel

            imagesetpixel($dest, $j, $i, $color_to_paint);

        

        }

    } 

    

    //this allows the new transparency info to be saved with the image

    imagesavealpha($dest, true);

    

    //write the image to the destination file

    imagepng($dest, $dest_path);

}

?>

pmidden at gmx dot net
28-Sep-2003 12:47


I've found a convenient way to "blit" one image into another. Using the following Code you can copy one image into another, leaving out the pixels with the specified transparent color. I'm using PNG but by replacing all PNG functions by JPEG or GIF functions you are able to use those formats as well:





<?php


$background = imagecreatefrompng("background.png");


$insert = imagecreatefrompng("insert.png");





// Either a color at a specific point on the image


// imagecolortransparent($insert,imagecolorat($insert,0,0));


// or a specific color (the color I used is magenta, #ff00ff)


imagecolortransparent($insert,imagecolorexact($insert,255,0,255));





$insert_x = imagesx($insert);


$insert_y = imagesy($insert);





// As said above, you can't use imagecopy (bug?)


imagecopymerge($background,$insert,0,0,0,0,$insert_x,$insert_y,100);





// imagejpeg or imagepng doesn't matter here


imagejpeg($background,"",100);


?>

matheus at slacklife dot com dot br
13-Sep-2003 07:24


// Image Resize

function createthumb($IMAGE_SOURCE,$THUMB_X,$THUMB_Y,$OUTPUT_FILE){

  $BACKUP_FILE = $OUTPUT_FILE . "_backup.jpg";

  copy($IMAGE_SOURCE,$BACKUP_FILE);

  $IMAGE_PROPERTIES = GetImageSize($BACKUP_FILE);

  if (!$IMAGE_PROPERTIES[2] == 2) {

    return(0);

  } else {

    $SRC_IMAGE = ImageCreateFromJPEG($BACKUP_FILE);

    $SRC_X = ImageSX($SRC_IMAGE);

    $SRC_Y = ImageSY($SRC_IMAGE);

    if (($THUMB_Y == "0") && ($THUMB_X == "0")) {

      return(0);

    } elseif ($THUMB_Y == "0") {

      $SCALEX = $THUMB_X/($SRC_X-1);

      $THUMB_Y = $SRC_Y*$SCALEX;

    } elseif ($THUMB_X == "0") {

      $SCALEY = $THUMB_Y/($SRC_Y-1);

      $THUMB_X = $SRC_X*$SCALEY;

    }

    $THUMB_X = (int)($THUMB_X);

    $THUMB_Y = (int)($THUMB_Y);

    $DEST_IMAGE = imagecreatetruecolor($THUMB_X, $THUMB_Y);

    unlink($BACKUP_FILE);

    if (!imagecopyresized($DEST_IMAGE, $SRC_IMAGE, 0, 0, 0, 0, $THUMB_X, $THUMB_Y, $SRC_X, $SRC_Y)) {

      imagedestroy($SRC_IMAGE);

      imagedestroy($DEST_IMAGE);

      return(0);

    } else {

      imagedestroy($SRC_IMAGE);

      if (ImageJPEG($DEST_IMAGE,$OUTPUT_FILE)) {

        imagedestroy($DEST_IMAGE);

        return(1);

      }

      imagedestroy($DEST_IMAGE);

    }

    return(0);

  }



} # end createthumb

schdenis at telecom dot by
02-May-2003 06:02


As you probably know 'gif' is a paletted image, that is why if you want to copy one 'gif' onto another 'gif' using ImageCopy you need to create a paletted destination image using (ImageCreate), not ImageCreateTrueColor.

mbostrom at paragee dot com
01-Dec-2002 04:56


If you want to copy a non-rectangular (hence transparent) image onto a background (for example, a pawn onto a chessboard) do the following:



First, create the pawn image pawn.png in your favorite graphics program.  Do NOT make the image transparent, instead, give it a distinct solid background color.  You will flag this color as transpernt inside PHP, otherwise imagecopy will not honor the transparency.



Then:



$board = imagecreatefrompng ("board.png");

$pawn  = imagecreatefrompng ("pawn.png");

imagecolortransparent ($pawn, imagecolorat ($pawn, 0, 0));

imagecopy ($board, $pawn, $x, $y, 0, 0, $pawnWidth, $pawnHeight);

imagedestroy ($pawn);

adam at shallimus dot com
05-Oct-2002 09:47


One way 'round the even/odd image size problem would be to use bcdiv.

robert at scpallas dot com
09-Feb-2002 12:33


If you are getting an error when using ImageCopy(), be sure that both images are of the same type - either True Color or Palette.

GD 1.x can copy images of different types, but with GD 2.0 this will cause an error.



sorry - forgot to fill in my email...

Note that ImageCreateFromJPEG always creates a True Color Image.

You can use ImageCreateTrueColor() instead of Image Create() to solve this problem.

jsnell at networkninja dot com
18-Feb-2001 11:09


Want to make an image tile properly?  This is accomplished by swapping all four quadrants of the image.  Here is some sample code that uses imagecopy to do it:





function backgroundify(&$image)


{


    $ix = imagesx($image);


    $iy = imagesy($image);


    $ixhalf = floor($ix / 2); // DON'T USE ON IMAGES WITH ODD SIZES! 


    $iyhalf = floor($iy /2);


    $panel_temp = ImageCreate ($ix, $iy) or die("Cannot Initialize new GD image stream");


    imagecopy($panel_temp, $image, 0,0,0,0,$ix, $iy);


    imagecopy($image, $panel_temp, 0,0,$ixhalf,$iyhalf, $ix-$ixhalf, $iy-$iyhalf); // move bottom right to top left


    imagecopy($image, $panel_temp, $ixhalf,$iyhalf, 0,0,$ix-$ixhalf, $iy-$iyhalf); // top left to bottom right


    imagecopy($image, $panel_temp, $ixhalf, 0,0,$iyhalf,$ix-$ixhalf, $iy-$iyhalf); // bottom left to topo right


    imagecopy($image, $panel_temp, 0,$iyhalf, $ixhalf,0,$ix-$ixhalf, $iy-$iyhalf); // top left to bottom right


}

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