PHP image resize function doesn't work properly - php

Question

I want to resize an image PNG with transparence plz help. Here is the code :
function createThumb($upfile, $dstfile, $max_width, $max_height){
$size = getimagesize($upfile);
$width = $size[0];
$height = $size[1];
$x_ratio = $max_width / $width;
$y_ratio = $max_height / $height;
if( ($width <= $max_width) && ($height <= $max_height)) {
$tn_width = $width;
$tn_height = $height;
} elseif (($x_ratio * $height) < $max_height) {
$tn_height = ceil($x_ratio * $height);
$tn_width = $max_width;
} else {
$tn_width = ceil($y_ratio * $width);
$tn_height = $max_height;
}
if($size['mime'] == "image/jpeg"){
$src = ImageCreateFromJpeg($upfile);
$dst = ImageCreateTrueColor($tn_width, $tn_height);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $tn_width, $tn_height,$width, $height);
imageinterlace( $dst, true);
ImageJpeg($dst, $dstfile, 100);
} else if ($size['mime'] == "image/png"){
$src = ImageCreateFrompng($upfile);
$dst = ImageCreateTrueColor($tn_width, $tn_height);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $tn_width, $tn_height,$width, $height);
// integer representation of the color black (rgb: 0,0,0)
$background = imagecolorallocate($dst, 255, 255, 0);
// removing the black from the placeholder
imagecolortransparent($dst, $background);
// turning off alpha blending (to ensure alpha channel information
// is preserved, rather than removed (blending with the rest of the
// image in the form of black))
imagealphablending($dst, false);
// turning on alpha channel information saving (to ensure the full range
// of transparency is preserved)
imagesavealpha($dst, true);
Imagepng($dst, $dstfile);
} else {
$src = ImageCreateFromGif($upfile);
$dst = ImageCreateTrueColor($tn_width, $tn_height);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $tn_width, $tn_height,$width, $height);
imagegif($dst, $dstfile);
}
}
The image source :
The current result (that I don't want) is :
How can I resize the image and maintain the transparency of the background color? Need help, please. Thanks.

Answer 1

imagecopyresampled is in the wrong place. This should be called after you have set the background colour:
$src = ImageCreateFrompng($upfile);
$dst = ImageCreateTrueColor($tn_width, $tn_height);
// use imagecolorallocatealpha to set BG as transparent:
$background = imagecolorallocatealpha($dst, 255, 255, 255, 127);
// turning off alpha blending as it's not needed
imagealphablending($dst, false);
// turning on alpha channel information saving (to ensure the full range
// of transparency is preserved)
imagesavealpha($dst, true);
// Do this here!
imagecopyresampled($dst, $src, 0, 0, 0, 0, $tn_width, $tn_height,$width, $height);
Imagepng($dst, $dstfile);

Answer 2

<?php
function createthumb($name, $newname, $new_w, $new_h, $border=false, $transparency=true, $base64=false) {
if(file_exists($newname))
#unlink($newname);
if(!file_exists($name))
return false;
$arr = split("\.",$name);
$ext = $arr[count($arr)-1];
if($ext=="jpeg" || $ext=="jpg"){
$img = #imagecreatefromjpeg($name);
} elseif($ext=="png"){
$img = #imagecreatefrompng($name);
} elseif($ext=="gif") {
$img = #imagecreatefromgif($name);
}
if(!$img)
return false;
$old_x = imageSX($img);
$old_y = imageSY($img);
if($old_x < $new_w && $old_y < $new_h) {
$thumb_w = $old_x;
$thumb_h = $old_y;
} elseif ($old_x > $old_y) {
$thumb_w = $new_w;
$thumb_h = floor(($old_y*($new_h/$old_x)));
} elseif ($old_x < $old_y) {
$thumb_w = floor($old_x*($new_w/$old_y));
$thumb_h = $new_h;
} elseif ($old_x == $old_y) {
$thumb_w = $new_w;
$thumb_h = $new_h;
}
$thumb_w = ($thumb_w<1) ? 1 : $thumb_w;
$thumb_h = ($thumb_h<1) ? 1 : $thumb_h;
$new_img = ImageCreateTrueColor($thumb_w, $thumb_h);
if($transparency) {
if($ext=="png") {
imagealphablending($new_img, false);
$colorTransparent = imagecolorallocatealpha($new_img, 0, 0, 0, 127);
imagefill($new_img, 0, 0, $colorTransparent);
imagesavealpha($new_img, true);
} elseif($ext=="gif") {
$trnprt_indx = imagecolortransparent($img);
if ($trnprt_indx >= 0) {
//its transparent
$trnprt_color = imagecolorsforindex($img, $trnprt_indx);
$trnprt_indx = imagecolorallocate($new_img, $trnprt_color['red'], $trnprt_color['green'], $trnprt_color['blue']);
imagefill($new_img, 0, 0, $trnprt_indx);
imagecolortransparent($new_img, $trnprt_indx);
}
}
} else {
Imagefill($new_img, 0, 0, imagecolorallocate($new_img, 255, 255, 255));
}
imagecopyresampled($new_img, $img, 0,0,0,0, $thumb_w, $thumb_h, $old_x, $old_y);
if($border) {
$black = imagecolorallocate($new_img, 0, 0, 0);
imagerectangle($new_img,0,0, $thumb_w, $thumb_h, $black);
}
if($base64) {
ob_start();
imagepng($new_img);
$img = ob_get_contents();
ob_end_clean();
$return = base64_encode($img);
} else {
if($ext=="jpeg" || $ext=="jpg"){
imagejpeg($new_img, $newname);
$return = true;
} elseif($ext=="png"){
imagepng($new_img, $newname);
$return = true;
} elseif($ext=="gif") {
imagegif($new_img, $newname);
$return = true;
}
}
imagedestroy($new_img);
imagedestroy($img);
return $return;
}
//example useage
createthumb("1.png", "2.png", 64,64,true, true, false);
?>
Hope this can help...
I dont deserve credit for this code... just found it op net... enjoy