I have inherited a site that creates a database of profiles. Part of this process is to upload an image, and re-size it to three different sizes.
Its worked fine for about 5 or 6 years when recently it suddenly started to produce 3 different sized black images.
I have tracked this down to a function, but I can't seem to find out what's wrong.
here are the errors that I have echoed out
Code:
$target_type=image/jpeg
imagecreatetruecolor was true
Warning: imagecopyresampled(): supplied argument is not a valid Image resource in /websites/LinuxPackage02/st/om/pm/..../public_html/admin/php/nslib_php/nslib_image.php on line 287
Warning: imagedestroy(): supplied argument is not a valid Image resource in /websites/LinuxPackage02/st/om/pm/.../public_html/admin/php/nslib_php/nslib_image.php on line 293
I'd really apprecaite any help anyone might be able to offer.
Here is the funtion - apologies for posting the whole thing - hope its not too long
Many thanks
Code:
function resize_image ($source_image, $target_image, $target_width, $target_height, $crop_position = false, $quality = 75) {
// set the memory limit higher and the execution time higher for the script as large
// attachments may be processed
ini_set('memory_limit', '32M');
ini_set('max_execution_time', '60');
$return_var = false; // initialise the return variable
// get the source file type
$source_type = get_mime_type($source_image);
// get the target file type
if (is_numeric(strpos(strtolower($target_image), 'jpg')) || is_numeric(strpos(strtolower($target_image), 'jpeg'))) {
// if the type is jpeg
$target_type = 'image/jpeg';
} elseif (is_numeric(strpos(strtolower($target_image), 'gif'))) {
// if the type id gif
$target_type = 'image/gif';
}
// get the dimensions of the source image and check whether the file is valid
if (list($source_width, $source_height) = getimagesize($source_image)) {
// calculate the dimensions of the new photo
// if there is no width set then calculate from the ratio of the source image and
// the height dimension
if (!$target_width) {
$target_width = ($source_width / $source_height ) * $target_height;
}
// if there is no height set then calculate from the ratio of the source image and
// the width dimension
if (!$target_height) {
$target_height = ($source_height / $source_width ) * $target_width;
}
// if the target filetype is a jpeg, create a truecolour image
if ($target_type == 'image/jpeg') {
//edward
echo '<h2>$target_type='.$target_type.'</h2>';
// create an empty image in memory with the target's dimensions
//$target_file = imagecreatetruecolor($target_width, $target_height);
if($target_file = imagecreatetruecolor($target_width, $target_height)){
echo '<h2>imagecreatetruecolor was true</h2>';
}else{
echo '<h2>imagecreatetruecolor was false</h2>';
};
} else {
// otherwise create a pallete based image
// create an empty image in memory with the target's dimensions
$target_file = imagecreate($target_width, $target_height);
}
//added this
//$target_image = imagecreatefromjpeg($target_file);
//$source_image = imagecreatefromjpeg($source_file);
//end of added this
// if the source image is a jpeg then load it
if ($source_type == 'image/jpeg') {
echo '<h2>source_type='.$source_type.'</h2>';
// load the source image as a jpeg from disk into memory
$source_file = imagecreatefromjpeg($source_image);
/* edward if($source_file = imagecreatefromjpeg($source_image)){
echo '<h2>imagecreatefromjpeg was true</h2>';
}else{
echo '<h2>imagecreatefromjpeg was false</h2>';
};*/
} elseif ($source_type == 'image/gif') {
// otherwise load the source image as a gif from disk into memory
$source_file = imagecreatefromgif($source_image);
}
// preset the source x and y positions of the output image
$source_x = 0;
$source_y = 0;
// copy the source width and height to some other variables used in calculation
$calc_width = $source_width;
$calc_height = $source_height;
// if it's specified that the image should be cropped
if ($crop_position) {
// calculate the source & target ratios
$source_ratio = $source_width / $source_height;
$target_ratio = $target_width / $target_height;
// calculate the other dimension
if ($source_ratio > $target_ratio) {
$source_width = ($target_width / $target_height ) * $calc_height;
} else {
$source_height = ($target_height / $target_width ) * $calc_width;
}
// depending on which crop position is selected, the calculations will be
// done to extract the required part
switch ($crop_position) {
case 'top':
$source_x = ($calc_width - $source_width) / 2;
$source_y = 0;
break;
case 'bottom':
$source_x = ($calc_width - $source_width) / 2;
$source_y = $calc_height - $source_height;
break;
case 'left':
$source_x = 0;
$source_y = ($calc_height - $source_height) / 2;
break;
case 'right':
$source_x = $calc_width - $source_width;
$source_y = ($calc_height - $source_height) / 2;
break;
default:
$source_x = ($calc_width - $source_width) / 2;
$source_y = ($calc_height - $source_height) / 2;
break;
}
}
// if a jpeg is to be created
if ($target_type == 'image/jpeg') {
// RESIZE the image with the parameters specified
imagecopyresampled($target_file, $source_file, 0, 0, $source_x, $source_y, $target_width, $target_height, $source_width, $source_height);
// remove the image of the source file from memory
imagedestroy($source_file);
// create a jpeg file on disk from the newly created image in memory and write to disk
$return_var = imagejpeg($target_file,$target_image, $quality);
// remove the image of the target file from memory
imagedestroy($target_file);
// if a gif file is to be created
} elseif ($target_type == 'image/gif') {
// RESAMPLE the image with the parameters specified
imagecopyresized($target_file, $source_file, 0, 0, $source_x, $source_y, $target_width, $target_height, $source_width, $source_height);
// remove the image of the source file from memory
imagedestroy($source_file);
// create a gif file on disk from the newly created image in memory and write to disk
$return_var = imagegif($target_file,$target_image);
// remove the image of the target file from memory
imagedestroy($target_file);
}
}
return $return_var; // return the status of the function
}
This may or may not be the case with your site. but its been my experience that due to software upgrades, code written years ago does not always work well or at all..
Black images eh? Before I look at the code, can you determine which file type(s) are doing that? PNG in particular seems to have an issue with this as it has an alpha channel that the JPEG doesn't have. Test it out with a JPG and a PNG file to see if both are black or if one is black.
Those the only two errors you're seeing from this output as well? I don't see an error on failing to create, so this leads me to believe (before I go through the code) that there is a branch that your not getting to that you expect to get to.
Just like any PHP error, you need to think logically and try to track the error. You can't assume things - bug fixing is a logical process.
Here you are getting error "imagecopyresampled(): supplied argument is not a valid Image resource" so obviously the error comes from the source file supplied, which possibly do not exist / was not created. Source is named $source_file , so you need to go to the place where that variable was created. I see it, for jpeg images:
$source_file = imagecreatefromjpeg($source_image);
Check and echo both $source_file and $source_image after this line and see if there is any error. Go backwards, if needed untill you find the source of the problem. Once the source is identified, check the PHP configurations via php_info(), check the manual and the comments on the http://php.net etc.
This is fairly a simple problem and only you can find the reason since you are the only one with access to the server. Don't panic, take it step by step going backwards.
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