Last updated: Fri, 26 Dec 2008

imagecopy

(PHP 4, PHP 5)

imagecopy — Copie une partie d'une image

Description

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

Copie une partie de l'image src_im sur l'image de destination dst_im , en commençant aux coordonnées src_x , src_y et sur la largeur de src_w et la hauteur de src_h . La portion ainsi définie sera copiée et placée aux coordonnées dst_x et dst_y .

Liste de paramètres

dst_im: Lien vers la ressource de l'image de destination.
src_im: Lien vers la ressource de l'image source.
dst_x: X : coordonnées du point de destination.
dst_y: Y : coordonnées du point de destination.
src_x: X : coordonnées du point source.
src_y: Y : coordonnées du point source.
src_w: Largeur de la source.
src_h: Hauteur de la source.

Valeurs de retour

Cette fonction retourne TRUE en cas de succès, FALSE en cas d'échec.

Exemples

Exemple #1 On coupe le logo PHP.net


<?php
// Création des instances d'image
$src = imagecreatefromgif('php.gif');
$dest = imagecreatetruecolor(80, 40);

// Copie
imagecopy($dest, $src, 0, 0, 20, 13, 80, 40);

// Affichage et libération de la mémoire
header('Content-Type: image/gif');
imagegif($dest);

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

L'exemple ci-dessus va afficher quelque chose de similaire à :

imagecopymerge

imageconvolution

Last updated: Fri, 26 Dec 2008

add a note User Contributed Notes
imagecopy

xafford
27-Sep-2008 03:53


concerning the previous post of Borszczuk and the function to mirror images:



There´s a way better (and faster) method for this task with imagecopyresampled.



<?php



define ( 'IMAGE_FLIP_HORIZONTAL', 1 );

define ( 'IMAGE_FLIP_VERTICAL', 2 );

define ( 'IMAGE_FLIP_BOTH', 3 );



function ImageFlip ( $imgsrc, $mode )

{



    $width                        =    imagesx ( $imgsrc );

    $height                       =    imagesy ( $imgsrc );



    $src_x                        =    0;

    $src_y                        =    0;

    $src_width                    =    $width;

    $src_height                   =    $height;



    switch ( (int) $mode )

    {



        case IMAGE_FLIP_HORIZONTAL:

            $src_y                =    $height;

            $src_height           =    -$height;

        break;



        case IMAGE_FLIP_VERTICAL:

            $src_x                =    $width;

            $src_width            =    -$width;

        break;



        case IMAGE_FLIP_BOTH:

            $src_x                =    $width;

            $src_y                =    $height;

            $src_width            =    -$width;

            $src_height           =    -$height;

        break;



        default:

            return $imgsrc;



    }



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



    if ( imagecopyresampled ( $imgdest, $imgsrc, 0, 0, $src_x, $src_y, $width, $height, $src_width, $src_height ) )

    {

        return $imgdest;

    }



    return $imgsrc;



}



?>

Cory Gagliardi
08-Jul-2008 09:40


Here is some simple code for resizing an uploaded image and inserting a watermark (from a 24-bit PNG) on the bottom right of it.  In this case, the water mark was a diagnol band that said "SOLD" across it.  The code that verifies the uploaded image is the correct type has been omitted:



<?PHP

//Load and resize the image

$uploaded = imagecreatefromjpeg($_FILES['file']['tmp_name']);

$image = imagecreatetruecolor(IMAGE_WIDTH, IMAGE_HEIGHT);

imagecopyresampled($image, $uploaded, 0, 0, 0, 0, IMAGE_WIDTH, IMAGE_HEIGHT, imagesx($uploaded), imagesy($uploaded));    

imagealphablending($image,true); //allows us to apply a 24-bit watermark over $image



//Load the sold watermark

$sold_band = imagecreatefrompng('../images/sold_band.png');

imagealphablending($sold_band,true);



//Apply watermark and save

$image = image_overlap($image, $sold_band);

imagecopy($image,$sold_band,IMAGE_WIDTH - SOLD_WIDTH,IMAGE_HEIGHT - SOLD_HEIGHT,0,0,SOLD_WIDTH,SOLD_HEIGHT);

$success = imagejpeg($image,'../images/sold/'.$id.'.jpg',85);



imagedestroy($image);

imagedestroy($uploaded);

imagedestroy($sold_band);

?>

matrebatre
02-Feb-2008 03:22


I had the same problem as Jeff, but his solution didn't work for me. I made this script, and it seems to work:





<?php





$img = imagecreatefromgif('in.gif');


$w = imagesx($img);


$h = imagesy($img);





$trans = imagecolortransparent($img);


if($trans >= 0) {





$rgb = imagecolorsforindex($img, $trans);





$oldimg = $img;


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


$color = imagecolorallocate($img,$rgb['red'],$rgb['green'],$rgb['blue']);


imagefilledrectangle($img,0,0,$w,$h,$color);


imagecopy($img,$oldimg,0,0,0,0,$w,$h);





}





imagegif($img,'out.gif');





?>

Jeff
23-Feb-2007 01:27


I came across the problem of having a page where any image could be uploaded, then I would need to work with it as a true color image with transparency. The problem came with palette images with transparency (e.g. GIF images), the transparent parts changed to black (no matter what color was actually representing transparent) when I used imagecopy to convert the image to true color.



To convert an image to true color with the transparency as well, the following code works (assuming $img is your image resource):



<?php

//Convert $img to truecolor

$w = imagesx($img);

$h = imagesy($img);

if (!imageistruecolor($img)) {

  $original_transparency = imagecolortransparent($img);

  //we have a transparent color

  if ($original_transparency >= 0) {

    //get the actual transparent color

    $rgb = imagecolorsforindex($img, $original_transparency);

    $original_transparency = ($rgb['red'] << 16) | ($rgb['green'] << 8) | $rgb['blue'];

    //change the transparent color to black, since transparent goes to black anyways (no way to remove transparency in GIF)

    imagecolortransparent($img, imagecolorallocate($img, 0, 0, 0));

  }

  //create truecolor image and transfer

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

  imagealphablending($img, false);

  imagesavealpha($img, true);

  imagecopy($truecolor, $img, 0, 0, 0, 0, $w, $h);

  imagedestroy($img);

  $img = $truecolor;

  //remake transparency (if there was transparency)

  if ($original_transparency >= 0) {

    imagealphablending($img, false);

    imagesavealpha($img, true);

    for ($x = 0; $x < $w; $x++)

      for ($y = 0; $y < $h; $y++)

        if (imagecolorat($img, $x, $y) == $original_transparency)

          imagesetpixel($img, $x, $y, 127 << 24);

  }

}

?>



And now $img is a true color image resource

john at mccarthy dot net
17-Jan-2007 03:37


Here is an upgrade of that cool wave function: Double the size of the image, wave it, then resample it down again. This makes even nicer, anti aliased waves.



    // So easy and nice!

    function wave_region($img, $x, $y, $width, $height,$amplitude = 4.5,$period = 30)

    {

        // Make a copy of the image twice the size

        $mult = 2;

        $img2 = imagecreatetruecolor($width * $mult, $height * $mult);

        imagecopyresampled ($img2,$img,0,0,$x,$y,$width * $mult,$height * $mult,$width, $height);



        // Wave it

        for ($i = 0;$i < ($width * $mult);$i += 2)

        {

           imagecopy($img2,$img2,

               $x + $i - 2,$y + sin($i / $period) * $amplitude,    // dest

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

               2,($height * $mult));

        }

        

        // Resample it down again

        imagecopyresampled ($img,$img2,$x,$y,0,0,$width, $height,$width * $mult,$height * $mult);

        imagedestroy($img2);

    }



To use it in a full image:

    wave_region ($oImage,0,0,imagesx($oImage),imagesy($oImage));

gilthans at NOSPAMgmail dot com
14-Jan-2007 09:19


This function does not resize the image. src_w and src_h are only used to define the portion of src_img that are going to be copied.

That is, it will copy src_img from coordinates src_x, src_y until src_w, src_h, and paste them on the dst_img starting from dst_x and dst_y.

If you wish to resize the image before copying it, check out 

ImageCopyResized (though note it is slightly slower when you don't need to resize the image).

alex at gateway-productions dot com
08-Jan-2007 01:34


Id just like to make a clarification



imagecopy ( resource dst_im, resource src_im, int dst_x, int dst_y, int src_x, int src_y, int src_w, int src_h )



width of src_w and a height of src_h 



Will not resize an image when resource src_im and resource dst_im are both defined



this may be a error with gd I believe I am running v2

C. Jansen
16-Aug-2006 09:02


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 01:27


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

02-Apr-2006 08:21


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 défaut

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

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

$filename=$_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
23-Feb-2006 06:26


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
10-Feb-2006 10:28


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
09-Feb-2006 09:38


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 06:21


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 01:17


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 06:48


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
20-Sep-2005 11:48


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 02:45


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
21-May-2005 09:09


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 02:25


<?



// ****  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 05:30


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
20-Dec-2004 07:45


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 02:25


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 01:09


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));

     &nb