Last updated: Mon, 26 Nov 2007

imagecopyresampled

(PHP 4 >= 4.0.6, PHP 5)

imagecopyresampled — 重采样拷贝部分图像并调整大小

说明

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() 将一幅图像中的一块正方形区域拷贝到另一个图像中，平滑地插入像素值，因此，尤其是，减小了图像的大小而仍然保持了极大的清晰度。如果成功则返回 TRUE，失败则返回 FALSE。

dst_image 和 src_image 分别是目标图像和源图像的标识符。如果源和目标的宽度和高度不同，则会进行相应的图像收缩和拉伸。坐标指的是左上角。本函数可用来在同一幅图内部拷贝（如果 dst_image 和 src_image 相同的话）区域，但如果区域交迭的话则结果不可预知。

Note: 因为调色板图像限制（255+1 种颜色）有个问题。重采样或过滤图像通常需要多于 255 种颜色，计算新的被重采样的像素及其颜色时采用了一种近似值。对调色板图像尝试分配一个新颜色时，如果失败我们选择了计算结果最接近（理论上）的颜色。这并不总是视觉上最接近的颜色。这可能会产生怪异的结果，例如空白（或者视觉上是空白）的图像。要跳过这个问题，请使用真彩色图像作为目标图像，例如用 imagecreatetruecolor() 创建的。

Note: 本函数需要 GD 2.0.1 或更高版本（推荐 2.0.28 及更高版本）。

范例

Example#1 简单例子

本例中将把一幅图像重采样为原始大小的一半。


<?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);
?>

Example#2 按比例重采样图像

本例将把一幅图像按最宽或最高 200 像素来显示。


<?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);

if ($width && ($width_orig < $height_orig)) {
    $width = ($height / $height_orig) * $width_orig;
} else {
    $height = ($width / $width_orig) * $height_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);
?>

参见

imagecopyresized()

imagecopyresized

imagecopymergegray

Last updated: Mon, 26 Nov 2007

add a note User Contributed Notes
imagecopyresampled

crash
12-Aug-2008 09:49


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 05:20


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
20-May-2008 01:53


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
19-Mar-2008 03:41


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
17-Mar-2008 02:58


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 06:45


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 11:51


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

wm at violet dot bg
21-Feb-2008 05:16


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
15-Jan-2008 02:09


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
20-Nov-2007 11:15


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 09:32


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
04-Oct-2007 11:57


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
26-Sep-2007 03:37


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, $src_w, $src_h)  {

    ImagePaletteCopy ($dst_img, $src_img);

    $rX = $src_w / $dst_w;

    $rY = $src_h / $dst_h;

    $w = 0;

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

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

        $t = 0;

        for ($x = $dst_x; $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)); 

        }

    }

}



function makeThumb($cale_in)  {

    global $thumbsize;

    $sursa = imagecreatefromjpeg($cale_in);

    $is_jpeg = getimagesize($cale_in);

    $ws = $is_jpeg[0];

    $hs = $is_jpeg[1];

    if($ws > $thumbsize[0] && $hs > $thumbsize[1])

    {

        $aspect = $ws/$hs;

        if($aspect <= 1.333333)  {

            $hd = $thumbsize[1];

            $wd = floor($hd*$aspect);

        }

        else  {

            $wd = $thumbsize[0];

            $hd = floor($wd/$aspect);

        } 

        $Z = ceil(log(($ws*$hs)/(4*$thumbsize[0]*$thumbsize[1])))+1;

        if(log(($ws*$hs)/(4*$thumbsize[0]*$thumbsize[1])) < 0) $Z=1;

        $dx = $dy = 0;

        if($Z > 1) {

            $dest = imagecreatetruecolor(round($ws/$Z), round($hs/$Z));

            for($i=0; $i < $hs; $i+=$Z) {

                for($j=0; $j < $ws; $j+=$Z) {

                    $rgb = imagecolorat($sursa, $j, $i);

                    $r = ($rgb >> 16) & 0xFF;

                    $g = ($rgb >> 8) & 0xFF;

                    $b = $rgb & 0xFF;

                    $pcol = imagecolorallocate($dest, $r, $g, $b);

                    imagesetpixel($dest, $dx, $dy, $pcol);

                    $dx++;

                }

                $dx=0;

                $dy++;

            }

        }

        else 

        {

            $dest = imagecreatetruecolor($ws, $hs);

            imagecopy($dest, $sursa, 0, 0, 0, 0, $ws, $hs );    

        }

        imagedestroy($sursa);

        $destrs = imagecreatetruecolor($wd, $hd);

        ImageCopyResampleBicubic($destrs,$dest,0,0,0,0,

$wd,$hd,round($ws/$Z),round($hs/$Z));

        ImageJpeg($destrs, $cale_out, 100);    

        echo "Z:$Z <b>|</b> ($ws x $hs) -> ($wd x $hd) @ ".$ws/$hs;

    }    

}



function mf() {

    list($usec, $sec) = explode(" ", microtime());

    $x[0] = $sec;  $x[1] = $usec;

    return $x;

}



$timp1 = mf(); //starting to count

makeThumb($cale_in); //makes the actual thumb

$timp2 = mf(); //timer ends

$dsec = $timp2[0] - $timp1[0];

$dusec = $timp2[1] - $timp1[1];

echo "<b>|</b> Time : <b>".round($dusec+$dsec,6)."s</b> <b>|</b><br />";



?>

tim at leethost dot com
08-Sep-2007 12:25


Here's an improved and corrected version of my fastimagecopyresampled script.  Because I typically scale entire images it appears my previous code was not properly tested.  In any case, this new script has been thoroughly tested, cleaned up, and enhanced.  The code is a little tighter and quality values between 0 and 1 will yield a mosaic effect (basically lowering quality below the pervious lowest value of 1).  I would still suggest using a quality of 2 to 4 as that's the primary purpose of this script, which is high quality and fast results.  Don't be afraid of using a quality value of 1.5 for extreme cases where you have a bunch of very large images from digital cameras (like those 10M pixel cameras theses days) and creating thumbnails in batch mode.  Even a quality of 1.5 is a big improvement over imagecopyresized and is ultra-fast.



Anyway, enjoy and I hope this is the bug-free last version.



<?

function fastimagecopyresampled (&$dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h, $quality = 3) {

  // Plug-and-Play fastimagecopyresampled function replaces much slower imagecopyresampled.

  // Just include this function and change all "imagecopyresampled" references to "fastimagecopyresampled".

  // Typically from 30 to 60 times faster when reducing high resolution images down to thumbnail size using the default quality setting.

  // Author: Tim Eckel - Date: 09/07/07 - Version: 1.1 - Project: FreeRingers.net - Freely distributable - These comments must remain.

  //

  // Optional "quality" parameter (defaults is 3). Fractional values are allowed, for example 1.5. Must be greater than zero.

  // Between 0 and 1 = Fast, but mosaic results, closer to 0 increases the mosaic effect.

  // 1 = Up to 350 times faster. Poor results, looks very similar to imagecopyresized.

  // 2 = Up to 95 times faster.  Images appear a little sharp, some prefer this over a quality of 3.

  // 3 = Up to 60 times faster.  Will give high quality smooth results very close to imagecopyresampled, just faster.

  // 4 = Up to 25 times faster.  Almost identical to imagecopyresampled for most images.

  // 5 = No speedup. Just uses imagecopyresampled, no advantage over imagecopyresampled.



  if (empty($src_image) || empty($dst_image) || $quality <= 0) { return false; }

  if ($quality < 5 && (($dst_w * $quality) < $src_w || ($dst_h * $quality) < $src_h)) {

    $temp = imagecreatetruecolor ($dst_w * $quality + 1, $dst_h * $quality + 1);

    imagecopyresized ($temp, $src_image, 0, 0, $src_x, $src_y, $dst_w * $quality + 1, $dst_h * $quality + 1, $src_w, $src_h);

    imagecopyresampled ($dst_image, $temp, $dst_x, $dst_y, 0, 0, $dst_w, $dst_h, $dst_w * $quality, $dst_h * $quality);

    imagedestroy ($temp);

  } else imagecopyresampled ($dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h);

  return true;

}

?>

eblejr AT phrebh DOT com
06-Sep-2007 02:38


Tim's code is fast, but if you're trying to put resampled images anywhere but in the top-left corner, it doesn't work.

Blendermf
05-Jul-2007 11:48


tim, your resampling gives me better results than the gd function. It looks just as good as what my image resizing software does.

kristijan at leftor dot ba
05-Jun-2007 05:09


There is bug in POST from tim at leethost dot com

25-Jan-2007 02:00.



Function work correctly when you making thumb from 0,0 to width/height. But if you want copy resized picture to other coordinates then you must change code in this:



function fastimagecopyresampled (&$dst_image, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h, $quality = 3) {

 if (empty($src_image) || empty($dst_image)) { return false; }

 if ($quality <= 1)

 {

   $temp = imagecreatetruecolor ($dst_w + 1, $dst_h + 1);

   imagecopyresized ($temp, $src_image, $dst_x, $dst_y, $src_x, $src_y, $dst_w + 1, $dst_h + 1, $src_w, $src_h);

   imagecopyresized ($dst_image, $temp, 0, 0, 0, 0, $dst_w, $dst_h, $dst_w, $dst_h);

   imagedestroy ($temp);

 }

 elseif ($quality < 5 && (($dst_w * $quality) < $src_w || ($dst_h * $quality) < $src_h))

 {

   $tmp_w = $dst_w * $quality;

   $tmp_h = $dst_h * $quality;

   $temp = imagecreatetruecolor ($tmp_w + 1, $tmp_h + 1);

   imagecopyresized ($temp, $src_image, 0, 0, $src_x, $src_y, $tmp_w + 1, $tmp_h + 1, $src_w, $src_h);

   imagecopyresam