JPEG Images Turn all black when converting from a PNG with PHP - php

The problem: When converting any PNG image into a JPEG, the image turns all black.
To start off, I've searched the internet and stackoverflow to find out how to do this. I've tried every method I could find in the PHP Manual and on Stack Overflow. The problem still exists. I'm using GD (don't have ImageMagick installed).
My code is below. This is the call to the function:
$tempImage = $dirPath.$filename.$tempMini.".jpg";
createTempImage($sourcefile, $tempImage, $tempMini_width, $tempMini_height, 100);
I've commented out the different methods that I've tried.
function createTempImage($sourcefile, $setNewName, $maxwidth, $maxheight, $quality){
$fileInfoArray = getimagesize($sourcefile);
$imagetype = $fileInfoArray['mime'];
if($imagetype == 'image/jpeg'){
$img = imagecreatefromjpeg($sourcefile);
}elseif($imagetype == 'image/gif'){
$img = imagecreatefromgif($sourcefile);
}elseif(($imagetype == 'image/png')||($imagetype == 'image/x-png')){
$img = imagecreatefrompng($sourcefile);
}
$width = imagesx( $img );
$height = imagesy( $img );
if ($width > $maxwidth || $height > $maxheight){
$factor = min(($maxwidth/$width),($maxheight/$height));
$newwidth = round($width*$factor);
$newheight = round($height*$factor);
} else {
$newwidth = $width;
$newheight = $height;
}
$tmpimg = imagecreatetruecolor( $newwidth, $newheight );
imagecopyresampled($tmpimg, $img, 0, 0, 0, 0, $newwidth, $newheight, $width, $height );
imagejpeg($tmpimg, $setNewName, 100);
imagedestroy($tmpimg);
imagedestroy($img);
}
The following have also been attempted:
$white = imagecolorallocate($tmpimg, 255, 255, 255);
ImageFill($tmpimg, 0, 0, $white);
ImageSaveAlpha($tmpimg, false);
ImageAlphaBlending($tmpimg, false);
$white = imagecolorallocate($tmpimg, 255, 255, 255);
imagefilledrectangle($tmpimg, 0, 0, $newwidth, $newheight, $white);
Update: The top black box is the image result: http://twitpic.com/30ywf5

Just a couple of ideas:
$newHeight = $maxheight; seems to be a typo, "newheight" is spelled without the capital "H" throughout the code.
The code to determine the new size can be shortened sigificantly:
if ($width > $maxwidth || $height > $maxheight){
$factor = min(($maxwidth/$width),($maxheight/$height));
$newwidth = round($width*$factor);
$newheight = round($height*$factor);
}
You use imagecopyresampled to create the new image - this only works in specific GD-versions ("version 2"), try to use imagecopyresized otherwise.

I seemed to have fixed the problem by recreating the whole function from scratch. Thank you guys for your input.
The problem was that PNG's weren't being uploaded. When executing the script with already uploaded URLs, it worked fine.
Thanks again.

Related

PHP GD Lib PNG-24 to PNG-8 conversion: The bigger the resulting image the less colors remain

The following code works with intial 8bit-png's but when i use a 24 bit alpha transp png, it seems to work worse when the resulting image gets bigger. The bigger the resulting image the less colors remain. Both pictures where exported from PS via Web-Export.
How can I solve the problem? Is something wrong with the code or may it be a bug? (I am on Windows 10, PHP 5.6.6)
$imgPath = 'image-24bit-alpha-transp-from-ps-960x533.png';
$imgDirname = pathinfo($imgPath, PATHINFO_DIRNAME);
$imgFilename = pathinfo($imgPath, PATHINFO_FILENAME);
$imgExtension = pathinfo($imgPath, PATHINFO_EXTENSI
ON);
$newWidths = [80, 160, 320, 640, 960];
$img = imagecreatefrompng($imgPath);
list($width, $height) = getimagesize($imgPath);
if($width * $height > PHP_INT_MAX)
throw new Exception('The picture exceeds the maximum number of pixels ('.INT_MAX.').');
$ratio = $height / $width;
$alphaTransparency = imagecolortransparent($img) >=0 || (ord(file_get_contents($imgPath, false, null, 25, 1)) & 4);
$numberOfColors = imagecolorstotal($img);
$trueColorImage = $numberOfColors === 0;
foreach($newWidths as $newWidth)
{
$newImgPath = $imgDirname.DIRECTORY_SEPARATOR.$imgFilename.'_w'.$newWidth.'.'.$imgExtension;
$newHeight = ceil($newWidth * $ratio);
$newImg = $trueColorImage ? imagecreatetruecolor($newWidth, $newHeight) : imagecreate($newWidth, $newHeight);
imagealphablending($newImg, false);
imagesavealpha($newImg,true);
$color = imagecolorallocatealpha($newImg, 255, 255, 255, 127);
imagefill($newImg, 0, 0, $color);
imagetruecolortopalette($newImg, false, $trueColorImage ? 255 : $numberOfColors);
imagecopyresampled($newImg, $img, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
imagepng($newImg, $newImgPath, 6);
imagedestroy($newImg);
}
imagedestroy($img);

PHP: Black strip on image while using GD library

I have a little problem with GD library in PHP - I resize image and then I want crop it to 320px (width) / 240px (height). Let me say that resized image is 320px/300px. When I crop it, a 1-px black strip appears on the bottom of the image - I don't know why.
I'm using imagecrop, imagecreatefromjpeg and imagecopyresampled
Here's the example:
Thanks for your time.
The code
$filename = '../store/projects/project-123.jpg';
$mime = mime_content_type($filename);
list($w, $h) = getimagesize($filename);
$prop = $w / $h;
$new_w = 0;
$new_h = 0;
if ($prop <= 4/3) {
$new_w = 320;
$new_h = (int)floor($h*($new_w/$w));
} else {
$new_h = 240;
$new_w = (int)floor($w*($new_h/$h));
}
$thumb = imagecreatetruecolor($new_w, $new_h);
if (strcmp($mime,'image/png') == 0) {
header('Content-Type: image/png');
$source = imagecreatefrompng($filename);
} else {
header('Content-Type: image/jpeg');
$source = imagecreatefromjpeg($filename);
}
imagecopyresampled($thumb, $source, 0, 0, 0, 0, $new_w, $new_h, $w, $h);
$filename = '../store/projects-thumbs/project-123.jpg';
$crop_data = array('x' => 0 , 'y' => 0, 'width' => 320, 'height'=> 240);
$thumb = imagecrop($thumb, $crop_data);
imagejpeg($thumb, $filename, 100);
imagedestroy($thumb);
imagedestroy($source);
imagecrop() has a known bug that causes the black bottom border to be added.
You can work around the problem using imagecopyresized(). See my answer to another SO question asking for an imagecrop() alternative.

Data Loss in JPEG/PNG resizing

I've adapted this code that I found. It resizes .jpg and .png images, and maintains alpha layers.
When I resize an image, however, the reduction in file size is far more than I had anticipated. This isn't a problem for me, as I cannot see with my eyes any degradation or data loss.
What is causing the huge compression of the file, and if I ever needed to, how can I avoid it?
function thumbnail($image, $width, $height, $target) {
if($image[0] != "/") { // Decide where to look for the image if a full path is not given
if(!isset($_SERVER["HTTP_REFERER"])) { // Try to find image if accessed directly from this script in a browser
$image = $_SERVER["DOCUMENT_ROOT"].implode("/", (explode('/', $_SERVER["PHP_SELF"], -1)))."/".$image;
} else {
$image = implode("/", (explode('/', $_SERVER["HTTP_REFERER"], -1)))."/".$image;
}
} else {
$image = $_SERVER["DOCUMENT_ROOT"].$image;
}
$image_properties = getimagesize($image);
$image_width = $image_properties[0];
$image_height = $image_properties[1];
$image_ratio = $image_width / $image_height;
$type = $image_properties["mime"];
if(!$width && !$height) {
$width = $image_width;
$height = $image_height;
}
if(!$width) {
$width = round($height * $image_ratio);
}
if(!$height) {
$height = round($width / $image_ratio);
}
if($type == "image/jpeg") {
header('Content-type: image/jpeg');
$thumb = imagecreatefromjpeg($image);
} elseif($type == "image/png") {
header('Content-type: image/png');
$thumb = imagecreatefrompng($image);
} else {
return false;
}
$temp_image = imagecreatetruecolor($width, $height);
imagealphablending($temp_image, false);
imagesavealpha($temp_image,true);
$transparent = imagecolorallocatealpha($temp_image, 255, 255, 255, 127);
imagefilledrectangle($temp_image, 0, 0, $nWidth, $nHeight, $transparent);
imagecopyresampled($temp_image, $thumb, 0, 0, 0, 0, $width, $height, $image_width, $image_height);
//$thumbnail = imagecreatetruecolor($width, $height);
//imagecopyresampled($thumbnail, $temp_image, 0, 0, 0, 0, $width, $height, $width, $height);
if($type == "image/jpeg") {
imagejpeg($temp_image, 'img/'.$target.'.jpg');
} else {
imagepng($temp_image,'img/'.$target.'.png');
}
imagedestroy($temp_image);
//imagedestroy($thumbnail);
}
As showdev commented, both imagejpeg() and imagepng() accept a third optional parameter for the image quality. For imagejpeg() it runs from 0 to 100 and defaults to 75), for imagepng() it is from 0 to 9 and defaults to 6.
Also, 4.4Mb is a really big size for a ~2.4Mpx image. It problably contains a lot of metadata and most of it -like Photoshop thumbsnails- is not preserved when you do an imagecopyresampled() with PHP's GD library.
You should also run one of your test images through a lossless compression program like JStrip (http://davidcrowell.com/jstrip/), to check how much it weights without the bloat.

download image from remote source and resize then save

Do any of you know of a good php class I can use to download an image from a remote source, re-size it to 120x120 and save it with a file name of my choosing?
So basically I would have an image at "http://www.site.com/image.jpg" save to my web server "/images/myChosenName.jpg" as a 120x120 pixels.
Thanks
You can try this:
<?php
$img = file_get_contents('http://www.site.com/image.jpg');
$im = imagecreatefromstring($img);
$width = imagesx($im);
$height = imagesy($im);
$newwidth = '120';
$newheight = '120';
$thumb = imagecreatetruecolor($newwidth, $newheight);
imagecopyresized($thumb, $im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
imagejpeg($thumb,'/images/myChosenName.jpg'); //save image as jpg
imagedestroy($thumb);
imagedestroy($im);
?>
More information about PHP image function : http://www.php.net/manual/en/ref.image.php
You can resize keeping the ratio of image
$im = imagecreatefromstring($img);
$width_orig = imagesx($im);
$height_orig = imagesy($im);
$width = '800';
$height = '800';
$ratio_orig = $width_orig/$height_orig;
if ($width/$height > $ratio_orig) {
$width = $height*$ratio_orig;
} else {
$height = $width/$ratio_orig;
}
If you're looking to have the ability to do this for both jpg and png file formats, here's what helped me:
$imgUrl = 'http://www.example.com/image.jpg';
// or $imgUrl = 'http://www.example.com/image.png';
$fileInfo = pathinfo($imgUrl);
$img = file_get_contents($imgUrl);
$im = imagecreatefromstring($img);
$originalWidth = imagesx($im);
$originalHeight = imagesy($im);
$resizePercentage = 0.5;
$newWidth = $originalWidth * $resizePercentage;
$newHeight = $originalHeight * $resizePercentage;
$tmp = imagecreatetruecolor($newWidth, $newHeight);
if ($fileInfo['extension'] == 'jpg') {
imagecopyresized($tmp, $im, 0, 0, 0, 0, $newWidth, $newHeight, $originalWidth, $originalHeight);
imagejpeg($tmp, '/img/myChosenName.jpg', -1);
}
else if ($fileInfo['extension'] == 'png') {
$background = imagecolorallocate($tmp , 0, 0, 0);
imagecolortransparent($tmp, $background);
imagealphablending($tmp, false);
imagesavealpha($tmp, true);
imagecopyresized($tmp, $im, 0, 0, 0, 0, $newWidth, $newHeight, $originalWidth, $originalHeight);
imagepng($tmp, '/img/myChosenName.png');
}
else {
// This image is neither a jpg or png
}
imagedestroy($tmp);
imagedestroy($im);
The extra code on the png side of things ensures that the saved image contains any and all transparent sections.

Remove the image resize ratio in OpenCart

I've look everywhere on how I could remove the image resizing in OpenCart but haven't find nothing about that.
I need that it resize but don't keep the ratio. I want the image to be just like I set it.
Here's the resize code in the system/library/image.php
public function resize($width = 0, $height = 0) {
if (!$this->info['width'] || !$this->info['height']) {
return;
}
$xpos = 0;
$ypos = 0;
$scale = min($width / $this->info['width'], $height / $this->info['height']);
if ($scale == 1) {
return;
}
$new_width = (int)($this->info['width'] * $scale);
$new_height = (int)($this->info['height'] * $scale);
$xpos = (int)(($width - $new_width) / 2);
$ypos = (int)(($height - $new_height) / 2);
$image_old = $this->image;
$this->image = imagecreatetruecolor($width, $height);
if (isset($this->info['mime']) && $this->info['mime'] == 'image/png') {
imagealphablending($this->image, false);
imagesavealpha($this->image, true);
$background = imagecolorallocatealpha($this->image, 255, 255, 255, 127);
imagecolortransparent($this->image, $background);
} else {
$background = imagecolorallocate($this->image, 255, 255, 255);
}
imagefilledrectangle($this->image, 0, 0, $width, $height, $background);
imagecopyresampled($this->image, $image_old, $xpos, $ypos, 0, 0, $new_width, $new_height, $this->info['width'], $this->info['height']);
imagedestroy($image_old);
$this->info['width'] = $width;
$this->info['height'] = $height;
}
What in that code could I remove so the image don't keep it's ratio on resize ?
First of all I would leave the default resizing tool as in some circumstances it might come in handy. What I did was add two more functions to resize images.
One function that crops an image so it fits the size set in the admin. Now empty white areas are added. This one is great for product lists. The second I added is a function that resizes an image so the biggest dimension will be set to the max size set in the admin. It will be scaled proportionally.
The new files are posted in an OpenCart forum thread.
I named the two extra functions cropsize and onesize. All you have to do is find the used resize functions in the controller and adjust this:
'thumb' => $this->model_tool_image
->resize($image,
$this->config->get('config_image_category_width'),
$this->config->get('config_image_category_height')));
to:
'thumb' => $this->model_tool_image
->cropsize($image,
$this->config->get('config_image_category_width'),
$this->config->get('config_image_category_height')));
The onesize function only needs one parameter so it's up to you but you could use something like this:
'popup' => $this->model_tool_image
->onesize($result['image'],
$this->config->get('config_image_popup_width'))
I hope this will help you getting better images.

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