Last updated: Fri, 01 Aug 2008

imagecopyresampled

(PHP 4 >= 4.0.6, PHP 5)

imagecopyresampled — Copy and resize part of an image with resampling

Descrierea

bool imagecopyresampled ( resource $dst_image , resource $src_image , int $dst_x , int $dst_y , int $src_x , int $src_y , int $dst_w , int $dst_h , int $src_w , int $src_h )

imagecopyresampled() copies a rectangular portion of one image to another image, smoothly interpolating pixel values so that, in particular, reducing the size of an image still retains a great deal of clarity.

In other words, imagecopyresampled() will take an rectangular area from src_image of width src_w and height src_h at position (src_x ,src_y ) and place it in a rectangular area of dst_image of width dst_w and height dst_h at position (dst_x ,dst_y ).

If the source and destination coordinates and width and heights differ, appropriate stretching or shrinking of the image fragment will be performed. The coordinates refer to the upper left corner. This function can be used to copy regions within the same image (if dst_image is the same as src_image ) but if the regions overlap the results will be unpredictable.

Parametri

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
dst_w: Destination width
dst_h: Destination height
src_w: Source width
src_h: Source height

Valorile întroarse

Întoarce valoarea TRUE în cazul succesului sau FALSE în cazul eşecului.

Exemple

Example #1 Simple example

This example will resample an image to half its original size.


<?php
// The file
$filename = 'test.jpg';
$percent = 0.5;

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

// Get new dimensions
list($width, $height) = getimagesize($filename);
$new_width = $width * $percent;
$new_height = $height * $percent;

// Resample
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

// Output
imagejpeg($image_p, null, 100);
?>

Exemplul de mai sus va afişa ceva similar cu:

Example #2 Resampling an image proportionally

This example will display an image with the maximum width, or height, of 200 pixels.


<?php
// The file
$filename = 'test.jpg';

// Set a maximum height and width
$width = 200;
$height = 200;

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

// Get new dimensions
list($width_orig, $height_orig) = getimagesize($filename);

$ratio_orig = $width_orig/$height_orig;

if ($width/$height > $ratio_orig) {
   $width = $height*$ratio_orig;
} else {
   $height = $width/$ratio_orig;
}

// Resample
$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);

// Output
imagejpeg($image_p, null, 100);
?>

Exemplul de mai sus va afişa ceva similar cu:

Note

Notă: There is a problem due to palette image limitations (255+1 colors). Resampling or filtering an image commonly needs more colors than 255, a kind of approximation is used to calculate the new resampled pixel and its color. With a palette image we try to allocate a new color, if that failed, we choose the closest (in theory) computed color. This is not always the closest visual color. That may produce a weird result, like blank (or visually blank) images. To skip this problem, please use a truecolor image as a destination image, such as one created by imagecreatetruecolor().

Vedeţi de asemenea

imagecopyresized()

imagecopyresized

imagecopymergegray

Last updated: Fri, 01 Aug 2008

add a note User Contributed Notes
imagecopyresampled

zorroswordsman at gmail dot com
24-Sep-2008 07:46


I've created a PHP5 image resize class, using ImageCopyResampled, that someone might find useful, with support for JPEG, PNG, and GIF formats. It retains the original image's aspect ratio when resizing, and doesn't resize or resample if the original width and height is smaller then the desired resize.



<?php



// Imaging

class imaging

{



    // Variables

    private $img_input;

    private $img_output;

    private $img_src;

    private $format;

    private $quality = 80;

    private $x_input;

    private $y_input;

    private $x_output;

    private $y_output;

    private $resize;



    // Set image

    public function set_img($img)

    {



        // Find format

        $ext = strtoupper(pathinfo($img, PATHINFO_EXTENSION));



        // JPEG image

        if(is_file($img) && ($ext == "JPG" OR $ext == "JPEG"))

        {



            $this->format = $ext;

            $this->img_input = ImageCreateFromJPEG($img);

            $this->img_src = $img;

            



        }



        // PNG image

        elseif(is_file($img) && $ext == "PNG")

        {



            $this->format = $ext;

            $this->img_input = ImageCreateFromPNG($img);

            $this->img_src = $img;



        }



        // GIF image

        elseif(is_file($img) && $ext == "GIF")

        {



            $this->format = $ext;

            $this->img_input = ImageCreateFromGIF($img);

            $this->img_src = $img;



        }



        // Get dimensions

        $this->x_input = imagesx($this->img_input);

        $this->y_input = imagesy($this->img_input);



    }



    // Set maximum image size (pixels)

    public function set_size($size = 100)

    {



        // Resize

        if($this->x_input > $size && $this->y_input > $size)

        {



            // Wide

            if($this->x_input >= $this->y_input)

            {



                $this->x_output = $size;

                $this->y_output = ($this->x_output / $this->x_input) * $this->y_input;



            }



            // Tall

            else

            {



                $this->y_output = $size;

                $this->x_output = ($this->y_output / $this->y_input) * $this->x_input;



            }



            // Ready

            $this->resize = TRUE;



        }



        // Don't resize

        else { $this->resize = FALSE; }



    }



    // Set image quality (JPEG only)

    public function set_quality($quality)

    {



        if(is_int($quality))

        {



            $this->quality = $quality;



        }



    }



    // Save image

    public function save_img($path)

    {



        // Resize

        if($this->resize)

        {



            $this->img_output = ImageCreateTrueColor($this->x_output, $this->y_output);

            ImageCopyResampled($this->img_output, $this->img_input, 0, 0, 0, 0, $this->x_output, $this->y_output, $this->x_input, $this->y_input);



        }



        // Save JPEG

        if($this->format == "JPG" OR $this->format == "JPEG")

        {



            if($this->resize) { imageJPEG($this->img_output, $path, $this->quality); }

            else { copy($this->img_src, $path); }



        }



        // Save PNG

        elseif($this->format == "PNG")

        {



            if($this->resize) { imagePNG($this->img_output, $path); }

            else { copy($this->img_src, $path); }



        }



        // Save GIF

        elseif($this->format == "GIF")

        {



            if($this->resize) { imageGIF($this->img_output, $path); }

            else { copy($this->img_src, $path); }



        }



    }



    // Get width

    public function get_width()

    {



        return $this->x_input;



    }



    // Get height

    public function get_height()

    {



        return $this->y_input;



    }



    // Clear image cache

    public function clear_cache()

    {



        @ImageDestroy($this->img_input);

        @ImageDestroy($this->img_output);



    }



}



##### DEMO #####



// Image

$src = "myimage.jpg";



// Begin

$img = new imaging;

$img->set_img($src);

$img->set_quality(80);



// Small thumbnail

$img->set_size(200);

$img->save_img("small_" . $src);



// Baby thumbnail

$img->set_size(50);

$img->save_img("baby_" . $src);



// Finalize

$img->clear_cache();



?>

crash
12-Aug-2008 06:49


The suggestion of converting a gif to a png to retain transparency was useful. However the steps used to maintain the transparency work for a gif as well, so the conversion step is not necessary. Just do everything the same, and save as a gif anyway. i.e.



<?php

$g_iw is new image width

$g_ih is new image height



$img_src=imagecreatefromgif($g_srcfile);

$img_dst=imagecreatetruecolor($g_iw,$g_ih);



//preserve alpha

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

imagealphablending($img_dst, false);

imagesavealpha($img_dst, true);

imagecopyresampled($img_dst, $img_src, 0, 0, 0, 0, $g_iw, $g_ih, $g_is[0], $g_is[1]);



imagegif($img_dst, $g_dstfile); 

imagedestroy($img_dst); 

?>

swizec at swizec dot com
17-Jul-2008 02:20


Wrote a function for sanitising user uploaded images. It saves the native image in size roughly 800x600 so it still fits on most screens when opened, makes a desired size thumbnail and turns all images into high quality jpegs for smaller bandwidth use.



Thumbnails are made in a similar way a designer would make them in photoshop, first resize the most troublesome dimension to desired size, then crop the rest out so the image retains proportions and most of it ends up in the thumbnail.



<?php 



// $image is $_FILES[ <image name> ]

// $imageId is the id used in a database or wherever for this image

// $thumbWidth and $thumbHeight are desired dimensions for the thumbnail

function processImage( $image, $imageId, $thumbWidth, $thumbHeight )

{

    $type = $image[ 'type' ];

    $galleryPath = 'images/collection/';

    

    if ( strpos( $type, 'image/' ) === FALSE )

    { // not an image

        return FALSE;

    }

    $type = str_replace( 'image/', '', $type );

    $createFunc = 'imagecreatefrom' . $type;

    

    $im = $createFunc( $image[ 'tmp_name' ] );

    

    $size = getimagesize( $image[ 'tmp_name' ] );

    

    $w = $size[ 0 ];

    $h = $size[ 1 ];

    if ( $w > 800 || $h > 600 )

    { // we make sure the image isn't too huge

        if ( $w > 800 )

        {

            $nw = 800;

            $nh = ceil( $nw*($h/$w) );

        }elseif( $h > 600 )

        {

            $nh = 600;

            $nw = ceil( $nh*($w/$h) );

        }

        

        $im2 = imagecreatetruecolor( $nw, $nh );

        imagecopyresampled( $im2, $im, 0, 0, 0, 0, $nw, $nh, $w, $h );

        imagedestroy( $im );

        

        $im = $im2;

        $w = $nw;

        $h = $nh;

    }

    

    // create thumbnail

    $tw = $thumbWidth;

    $th = $thumbHeight;

    $imT = imagecreatetruecolor( $tw, $th );

    

    if ( $tw/$th > $th/$tw )

    { // wider

        $tmph = $h*($tw/$w);

        $temp = imagecreatetruecolor( $tw, $tmph );

        imagecopyresampled( $temp, $im, 0, 0, 0, 0, $tw, $tmph, $w, $h ); // resize to width

        imagecopyresampled( $imT, $temp, 0, 0, 0, $tmph/2-$th/2, $tw, $th, $tw, $th ); // crop

        imagedestroy( $temp );

    }else

    { // taller

        $tmpw = $w*($th/$h );

        $imT = imagecreatetruecolor( $tmpw, $th );

        imagecopyresampled( $imT, $im, 0, 0, 0, 0, $tmpw, $h, $w, $h ); // resize to height

        imagecopyresampled( $imT, $temp, 0, 0, $tmpw/2-$tw/2, 0, $tw, $th, $tw, $th ); // crop

        imagedestroy( $temp );

    }

    

    // save the image

    imagejpeg( $im, $galleryPath . $imgid . '.jpg', 100 );

    imagejpeg( $imT, $galleryPath . $imgid . '_thumb.jpg', 100 );

}



?>

mattura gmail com
19-May-2008 10:53


Here's a little function I wrote to resize images to a maximum dimension - based on what facebook does in the galleries. You put in a source, destination and a maximum dimension in pixels (eg 300), and for example if the image is long and thin, the longest edge will be 300px, yet the image retains proportions. A square image will become 300x300, a 6x4 (landscape) will become 300x200, a 4x6 (portrait) - 200x300 etc.

It works on jpg images, but other formats can easily be added.

<?php

function createThumb($spath, $dpath, $maxd) {

 $src=@imagecreatefromjpeg($spath);

 if (!$src) {return false;} else {

  $srcw=imagesx($src);

  $srch=imagesy($src);

  if ($srcw<$srch) {$height=$maxd;$width=floor($srcw*$height/$srch);}

  else {$width=$maxd;$height=floor($srch*$width/$srcw);}

  if ($width>$srcw && $height>$srch) {$width=$srcw;$height=$srch;}  //if image is actually smaller than you want, leave small (remove this line to resize anyway)

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

  if ($height<100) {imagecopyresized($thumb, $src, 0, 0, 0, 0, $width, $height, imagesx($src), imagesy($src));}

  else {imagecopyresampled($thumb, $src, 0, 0, 0, 0, $width, $height, imagesx($src), imagesy($src));}

  imagejpeg($thumb, $dpath);

  return true;

 }

}

?>

bobbyboyojones at hotmail dot com
18-Mar-2008 12:41


I hated that enlarging an image resulted in giant pixels rather than a smoother look, so I wrote this function.  It takes longer, but gives a much nicer look.



<?php



function imagecopyresampledSMOOTH(&$dst_img, &$src_img, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h, $mult=1.25){

    // don't use a $mult that's too close to an int or this function won't make much of a difference



    $tgt_w = round($src_w * $mult);

    $tgt_h = round($src_h * $mult);

    

    // using $mult <= 1 will make the current step w/h smaller (or the same), don't allow this, always resize by at least 1 pixel larger

    if($tgt_w <= $src_w){ $tgt_w += 1; }

    if($tgt_h <= $src_h){ $tgt_h += 1; }

    

    // if the current step w/h is larger than the final height, adjust it back to the final size

    // this check also makes it so that if we are doing a resize to smaller image, it happens in one step (since that's already smooth)

    if($tgt_w > $dst_w){ $tgt_w = $dst_w; }

    if($tgt_h > $dst_h){ $tgt_h = $dst_h; }



    $tmpImg = imagecreatetruecolor($tgt_w, $tgt_h);



    imagecopyresampled($tmpImg, $src_img, 0, 0, $src_x, $src_y, $tgt_w, $tgt_h, $src_w, $src_h);

    imagecopy($dst_img, $tmpImg, $dst_x, $dst_y, 0, 0, $tgt_w, $tgt_h);

    imagedestroy($tmpImg);



    // as long as the final w/h has not been reached, reep on resizing

    if($tgt_w < $dst_w OR $tgt_h < $dst_h){

        imagecopyresampledSMOOTH($dst_img, $dst_img, $dst_x, $dst_y, $dst_x, $dst_y, $dst_w, $dst_h, $tgt_w, $tgt_h, $mult);

    }

}



?>

arnar at netvistun dot is
16-Mar-2008 11:58


A small thumb script. Lets you specify max height and width. The thumb will always be of a rectangular shape while the image itself retains it's proportions. Very clean.



<?php

// The file

$filename = 'a.jpg';



// Set a maximum height and width

$width = 80;

$height = 80;



$thumbsize = 80;



// Content type

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



// Get new dimensions

list($width_orig, $height_orig) = getimagesize($filename);



$ratio_orig = $width_orig/$height_orig;



if ($width/$height > $ratio_orig) {

   $width = $height*$ratio_orig;

} else {

   $height = $width/$ratio_orig;

}



// Resample

$image_p = imagecreatetruecolor($thumbsize, $thumbsize);

$image = imagecreatefromjpeg($filename);

imagecopyresampled($image_p, $image, -($width/2) + ($thumbsize/2), -($height/2) + ($thumbsize/2), 0, 0, $width, $height, $width_orig, $height_orig);



// Output

imagejpeg($image_p, null, 100);

?>

rayg at daylongraphics dot com
07-Mar-2008 02:45


Here's a simple function to resample one JPEG imagefile to another while keeping aspect ratio of the source within the destination's dimensions. You can also tune the allowable distortion if you end up making too many thumbnails with thin blank areas around them. Should work when enlarging images too. Function returns true if it worked, false if not.



function resample_picfile($src, $dst, $w, $h)

{

    // If distortion stretching is within the range below,

    // then let image be distorted.

    $lowend = 0.8;

    $highend = 1.25;



    $src_img = imagecreatefromjpeg($src);

    if($src_img)

    {

        $dst_img = ImageCreateTrueColor($w, $h);

        /* if you don't want aspect-preserved images 

to have a black bkgnd, fill $dst_img with the color of your choice here. 

        */



        if($dst_img)

        {

            $src_w = imageSX($src_img);

            $src_h = imageSY($src_img);



            $scaleX = (float)$w / $src_w;

            $scaleY = (float)$h / $src_h;

            $scale = min($scaleX, $scaleY);



            $dstW = $w;

            $dstH = $h;

            $dstX = $dstY = 0;



            $scaleR = $scaleX / $scaleY;

            if($scaleR < $lowend || $scaleR > $highend)

            {

                $dstW = (int)($scale * $src_w + 0.5);

                $dstH = (int)($scale * $src_h + 0.5);



                // Keep pic centered in frame.

                $dstX = (int)(0.5 * ($w - $dstW));

                $dstY = (int)(0.5 * ($h - $dstH));

            }

            

            imagecopyresampled(

                $dst_img, $src_img, $dstX, $dstY, 0, 0, 

                $dstW, $dstH, $src_w, $src_h); 

            imagejpeg($dst_img, $dst); 

            imagedestroy($dst_img);

        }

        imagedestroy($src_img);

        return file_exists($dst);

    }

    return false;

}

RandomFeatureRequest
02-Mar-2008 07:51


If anyone felt like implementing Bicubic Sharper and/or Bicubic Smoother, that would seriously rock.

wm at violet dot bg
20-Feb-2008 01:16


This is a fixed version of ImageCopyResampledBicubic posted by liviu.malaescu

The original version wasn't respecting src_x & src_y args



<?php

    function ImageCopyResampledBicubic(&$dst_image, &$src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h)  {

        // we should first cut the piece we are interested in from the source

        $src_img = ImageCreateTrueColor($src_w, $src_h);

        imagecopy($src_img, $src_image, 0, 0, $src_x, $src_y, $src_w, $src_h);



        // this one is used as temporary image

        $dst_img = ImageCreateTrueColor($dst_w, $dst_h);



        ImagePaletteCopy($dst_img, $src_img);

        $rX = $src_w / $dst_w;

        $rY = $src_h / $dst_h;

        $w = 0;

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

            $ow = $w; $w = round(($y + 1) * $rY);

            $t = 0;

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

                $r = $g = $b = 0; $a = 0;

                $ot = $t; $t = round(($x + 1) * $rX);

                for ($u = 0; $u < ($w - $ow); $u++)  {

                    for ($p = 0; $p < ($t - $ot); $p++)  {

                        $c = ImageColorsForIndex($src_img, ImageColorAt($src_img, $ot + $p, $ow + $u));

                        $r += $c['red'];

                        $g += $c['green'];

                        $b += $c['blue'];

                        $a++;

                    }

                }

                ImageSetPixel($dst_img, $x, $y, ImageColorClosest($dst_img, $r / $a, $g / $a, $b / $a));

            }

        }



        // apply the temp image over the returned image and use the destination x,y coordinates

        imagecopy($dst_image, $dst_img, $dst_x, $dst_y, 0, 0, $dst_w, $dst_h);



        // we should return true since ImageCopyResampled/ImageCopyResized do it

        return true;

    }

?>

Michael Shepanski
14-Jan-2008 10:09


Here is a function I thought I would share that will resample and copy an image with rounded corners.



<?php

/** ------------------------------------------------------------

 * Copy and resample an image with rounded corners.

 * ----------------------------------------------------------- */

function imageRoundedCopyResampled(&$dstimg, &$srcimg, $dstx, $dsty, $srcx,

                                   $srcy, $dstw, $dsth, $srcw, $srch, $radius) {

    # Resize the Source Image

    $srcResized = imagecreatetruecolor($dstw, $dsth);

    imagecopyresampled($srcResized, $srcimg, 0, 0, $srcx, $srcy,

                       $dstw, $dsth, $srcw, $srch);

    # Copy the Body without corners

    imagecopy($dstimg, $srcResized, $dstx+$radius, $dsty,

              $radius, 0, $dstw-($radius*2), $dsth);

    imagecopy($dstimg, $srcResized, $dstx, $dsty+$radius,

              0, $radius, $dstw, $dsth-($radius*2));

    # Create a list of iterations; array(array(X1, X2, CenterX, CenterY), ...)

    # Iterations in order are: Top-Left, Top-Right, Bottom-Left, Bottom-Right

    $iterations = array(

        array(0, 0, $radius, $radius),

        array($dstw-$radius, 0, $dstw-$radius, $radius),

        array(0, $dsth-$radius, $radius, $dsth-$radius),

        array($dstw-$radius, $dsth-$radius, $dstw-$radius, $dsth-$radius)

    );

    # Loop through each corner 'iteration'

    foreach($iterations as $iteration) {

        list($x1,$y1,$cx,$cy) = $iteration;

        for ($y=$y1; $y<=$y1+$radius; $y++) {

            for ($x=$x1; $x<=$x1+$radius; $x++) {

                # If length (X,Y)->(CX,CY) is less then radius draw the point

                $length = sqrt(pow(($cx - $x), 2) + pow(($cy - $y), 2));

                if ($length < $radius) {

                    imagecopy($dstimg, $srcResized, $x+$dstx, $y+$dsty,

                              $x, $y, 1, 1);

                }

            }

        }

    }

}

?>

matt1walsh DESPAMMER gmail dot com
19-Nov-2007 07:15


None of the stuff I've seen for resizing transparent GIFs works consistently and yields a good image. The hack I thought of is silly, but it works okay -- convert GIF to PNG. This worked for me.



$g_iw is new image width

$g_ih is new image height



$img_src=imagecreatefromgif($g_srcfile);

$img_dst=imagecreatetruecolor($g_iw,$g_ih);



//preserve alpha

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

imagealphablending($img_dst, false);

imagesavealpha($img_dst, true);

imagecopyresampled($img_dst, $img_src, 0, 0, 0, 0, $g_iw, $g_ih, $g_is[0], $g_is[1]);



imagepng($img_dst, $g_dstfile); 

imagedestroy($img_dst);

Dave McCourt
12-Nov-2007 05:32


This function is taken from lots of web sources so thanks to all for posting. It creates square or landscape thumbnails from .jpgs  from either portait or landscape original images. I decide in advance which way I want the thumbs to display for consistency. I usually sharpen the images as well post-upload, to save on server resources. I can post this code if anyone wants it. I hope this helps someone...



    # create thumbnails from jpgs

    # usage:

    # create_jpgthumb(uploaded file, final file (with path), thumb height, thumb width, jpg quality, scale thumb (true) or fixed size (false); 

    function create_jpgthumb($original, $thumbnail, $max_width, $max_height, $quality, $scale = true) {

        

        list ($src_width, $src_height, $type, $w) = getimagesize($original);

        

        if (!$srcImage = @imagecreatefromjpeg($original)) {

            return false;

        }



        # image resizes to natural height and width

        if ($scale == true) {

                        

            if ($src_width > $src_height ) {

                $thumb_width = $max_width;

                $thumb_height = floor($src_height * ($max_width / $src_width));

            } else if ($src_width < $src_height ) {

                $thumb_height = $max_height;

                $thumb_width = floor($src_width * ($max_height / $src_height));

            } else {

                $thumb_width = $max_height;

                $thumb_height = $max_height;

            }



            if (!@$destImage = imagecreatetruecolor($thumb_width, $thumb_height)) {

                return false;

            }

            

            if (!@imagecopyresampled($destImage, $srcImage, 0, 0, 0, 0, $thumb_width, $thumb_height, $src_width, $src_height)) {

                return false;

            }

                        

        # image is fixed to supplied width and height and cropped

        } else if ($scale == false) {

        

            $ratio = $max_width / $max_height;

                

            # thumbnail is landscape

             if ($ratio > 1) {

             

                # uploaded pic is landscape

                if ($src_width > $src_height) {



                    $thumb_width = $max_width;

                    $thumb_height = ceil($max_width * ($src_height / $src_width));

                    

                    if ($thumb_height > $max_width) {

                        $thumb_height = $max_width;

                        $thumb_width = ceil($max_width * ($src_width / $src_height));

                    }



                # uploaded pic is portrait

                } else {

                

                    $thumb_height = $max_width;

                    $thumb_width = ceil($max_width * ($src_height / $src_width));

                    

                    if ($thumb_width > $max_width) {

                        $thumb_width = $max_width;

                        $thumb_height = ceil($max_width * ($src_height / $src_width));

                    }

                    

                    $off_h = ($src_height - $src_width) / 2;

            

                }

    

                if (!@$destImage = imagecreatetruecolor($max_width, $max_height)) {

                    return false;

                }

        

                if (!@imagecopyresampled($destImage, $srcImage, 0, 0, 0, $off_h, $thumb_width, $thumb_height, $src_width, $src_height)) {

                    return false;

                }



            # thumbnail is square

             } else {

             

                if ($src_width > $src_height) {

                    $off_w = ($src_width - $src_height) / 2;

                    $off_h = 0;

                    $src_width = $src_height;

                } else if ($src_height > $src_width) {

                    $off_w = 0;

                    $off_h = ($src_height - $src_width) / 2;

                    $src_height = $src_width;

                } else {

                    $off_w = 0;

                    $off_h = 0;

                }



                if (!@$destImage = imagecreatetruecolor($max_width, $max_height)) {

                    return false;

                }

        

                if (!@imagecopyresampled($destImage, $srcImage, 0, 0, $off_w, $off_h, $max_width, $max_height, $src_width, $src_height)) {

                    return false;

                }



             }

         

                            

        }

        

        @imagedestroy($srcImage);



        if (!@imageantialias($destImage, true)) {

            return false;

        }

        

        if (!@imagejpeg($destImage, $thumbnail, $quality)) {

            return false;

        }

                        

        @imagedestroy($destImage);

        

        return true;

    }

tim dot daldini at gmail dot be
03-Oct-2007 08:57


Tim's function is a whole lot faster, however, the quality setting doesnt seem right since resizing very big images doesnt affect quality of the resulting thumbnails that much on quality 1 for example.



Anyone has figured out how to use a more correct quality setting by comparing image surfaces (for example) basing on Tim's function?



images with a total of 10Megapixels that contain 5Megapixels when resized should use the same quality setting like images that contain 1Megapixels but only 0.5 when resized.



Not hard to understand, but the memoryload would be a lot lower if the function could decide to use a setting of quality 1 automatically when resizing big images to small thumbnails. This would be handy especially when using the function for images of various sizes in the same application.

liviu dot malaescu at gmail dot com
25-Sep-2007 12:37


3800x2500px - 2s

3807x6768 - 4.7s 

Tested on a core2duo e4300/1gb ram - only one core used.

It reduces first with nearest-neighbour and then with bicubic on the smaller image. 

Thumb quality is fine :)



<?php

$cale_in = "test.jpg"; //input-file

$cale_out = "test_thumb.jpg"; //output-file

$make_thumbs = "YES";

$thumbsize[0] = 100;

$thumbsize[1] = 75;

ini_set("memory_limit", "134217728"); // needed for huge pictures



// Bicubic resampling, not written by me

function ImageCopyResampleBicubic 

(&$dst_img, &$src_img, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h