PHP: Black strip on image while using GD library - php

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.

Related

resize bulk of images on 1280x 720 without cropping

I have 60 jpg images inside img folder
they are all of various dimensions
need all of them to be 1280 x 720
white background - if needed
using this code spinner on page works obut 10 seconds - meaning the code works something - but final result is - nothing
each image has the same dimension as before
pls help
function resize_no_crop($el, $w, $h) {
list($width, $height) = getimagesize($el);
$r = $width / $height;
if ($w/$h > $r) {
$newwidth = $h*$r;
$newheight = $h;
} else {
$newheight = $w/$r;
$newwidth = $w;
}
$src = imagecreatefromjpeg($el);
$dst = imagecreatetruecolor($newwidth, $newheight);
imagecopyresampled($dst, $src, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
return $dst;
}
$arr = glob('img/*');
foreach($arr as $el){resize_no_crop($el, 1280, 720);}
echo 'finito';
You aren't saving the images:
$quality = 95;
foreach($arr as $el){
// Destinazione
$dest = dirname($el).DIRECTORY_SEPARATOR.basename($el, '.jpg') . '.cropped.jpg';
$resized = resize_no_crop($el, 1280, 720);
imagejpeg($resized, $dest, $quality);
}
Or you cal use $dest = $el to overwrite the original images (I never recommend this).
Use Imagick resizeImage:
foreach($arr as $el) {
$im = new \Imagick();
$im->readImage($el);
$im->resizeImage(1280, 720, \Imagick::FILTER_BOX, 1);
$im->writeImage($el);
$im->destroy();
}
From documentation: https://www.php.net/manual/en/imagick.resizeimage.php

Image cropping with fixed aspect ratio

I'm trying to take in two sets of x-y co-ordinates from an image in a 7:9 aspect ratio and replace the original image with the cropped section in a 280x360 image, but it's not working. It's not throwing up any errors but the image replacement after cropping doesn't seem to work. Echoing data tells me it takes in everything up to the imagecopyresampled code.
$formDatax1=$_POST["x1"];
$formDatax2=$_POST["x2"];
$formDatay1=$_POST["y1"];
$formDatay2=$_POST["y2"];
$filename='http://pathtofiles/path/photo/'.$a_photo;
$image_info = getimagesize($filename);
switch(strtolower($image_info['mime'])){
case 'image/png' : $image = imagecreatefrompng($filename); $imgtype='png'; break;
case 'image/jpeg': $image = imagecreatefromjpeg($filename); $imgtype='jpg'; break;
case 'image/gif' : $image = imagecreatefromgif($filename); $imgtype='gif'; break;
default: die();
}
$resized_width = ((int)$formDatax2) - ((int)$formDatax1);
$resized_height = ((int)$formDatay2) - ((int)$formDatay1);
$resized_image = imagecreatetruecolor(280, 360);
imagecopyresampled($resized_image, $image, 0, 0, (int)$formDatax1, (int)$formDatay1, 280, 360, $resized_width, $resized_height);
if ($imgtype=='png') {
imagepng($resized_image, $filename);
}
if ($imgtype=='jpg') {
imagejpeg($resized_image, $filename);
}
if ($imgtype=='gif') {
imagejpeg($resized_image, $filename);
}
echo '<script type="text/javascript">alert("Image cropped!"); </script>';
exit();
You're not specifying a new value for $filename. The http[s] URL wrappers can retrieve a file, but not write. You'll need to specify a local filesystem location to save the image to.
This solution is from PHP cookbook 3rd edition
Use the ImageCopyResampled() function, scaling the image as needed.
To shrink proportionally:
$filename = __DIR__ . '/php.png';
$scale = 0.5; // Scale
// Images
$image = ImageCreateFromPNG($filename);
$thumbnail = ImageCreateTrueColor(
ImageSX($image) * $scale,
ImageSY($image) * $scale);
// Preserve Transparency
ImageColorTransparent($thumbnail,
ImageColorAllocateAlpha($thumbnail, 0, 0, 0, 127));
ImageAlphaBlending($thumbnail, false);
ImageSaveAlpha($thumbnail, true);
// Scale & Copy
ImageCopyResampled($thumbnail, $image, 0, 0, 0, 0,
ImageSX($thumbnail), ImageSY($thumbnail),
ImageSX($image), ImageSY($image));
// Send
header('Content-type: image/png');
ImagePNG($thumbnail);
ImageDestroy($image);
ImageDestroy($thumbnail);
To shrink to a fixed-size rectangle:
// Rectangle Version
$filename = __DIR__ . '/php.png';
// Thumbnail Dimentions
$w = 50; $h = 20;
// Images
$original = ImageCreateFromPNG($filename);
$thumbnail = ImageCreateTrueColor($w, $h);
// Preserve Transparency
ImageColorTransparent($thumbnail,
ImageColorAllocateAlpha($thumbnail, 0, 0, 0, 127));
ImageAlphaBlending($thumbnail, false);
ImageSaveAlpha($thumbnail, true);
// Scale & Copy
$x = ImageSX($original);
$y = ImageSY($original);
$scale = min($x / $w, $y / $h);
ImageCopyResampled($thumbnail, $original,
0, 0, ($x - ($w * $scale)) / 2, ($y - ($h * $scale)) / 2,
$w, $h, $w * $scale, $h * $scale);
// Send
header('Content-type: image/png');
ImagePNG($thumbnail);
ImageDestroy($original);
ImageDestroy($thumbnail);

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.

Upload, resize, and crop center of image with PHP

I'm wanting to create a very very basic upload, resize, and crop PHP script.
The functionality to this will be identical (last i checked anyway) to the method Twitter uses to upload avatar pictures.
I want the script to take any size image, resize the shortest side to 116px, then crop off the top and bottom (or left and right side if it's landscape) as to get a square 116px by 116px.
I don't want a bloated PHP script with client side resizing or anything, just a simple PHP resize and crop. How is this done?
The GD Library is a good place to start.
http://www.php.net/manual/en/book.image.php
There a simple to use, open source library called PHP Image Magician. It uses GD but simplifies it's usage to 3 lines.
Example of basis usage:
$magicianObj = new imageLib('racecar.jpg');
$magicianObj -> resizeImage(100, 200, 'crop');
$magicianObj -> saveImage('racecar_small.png');
If you want an example to work from my upload, resize and crop class does all of this plus some other cool stuff - you can use it all if needed or just take the bits out that you like:
http://www.mjdigital.co.uk/blog/php-upload-and-resize-image-class/
I don't think it is too bloated! - you can just do something this (not tested):
if((isset($_FILES['file']['error']))&&($_FILES['file']['error']==0)){ // if a file has been posted then upload it
include('INCLUDE_CLASS_FILE_HERE.php');
$myImage = new _image;
// upload image
$myImage->uploadTo = 'uploads/'; // SET UPLOAD FOLDER HERE
$myImage->returnType = 'array'; // RETURN ARRAY OF IMAGE DETAILS
$img = $myImage->upload($_FILES['file']);
if($img) {
$myImage->newWidth = 116;
$myImage->newHeight = 116;
$i = $myImage->resize(); // resizes to 116px keeping aspect ratio
// get new image height
$imgWidth = $i['width'];
// get new image width
$imgHeight = $i['height'];
if($i) {
// work out where to crop it
$cropX = ($imgWidth>116) ? (($imgWidth-116)/2) : 0;
$cropY = ($imgHeight>116) ? (($imgHeight-116)/2) : 0;
$cropped = $myImage->crop(116,116,$cropX,$cropY);
if($cropped) { echo 'It Worked (I think!)'; print_r($cropped);
} else { echo 'Crop failed'; }
} else { echo 'Resize failed'; }
} else { echo 'Upload failed'; }
I made this simple function which is very easy to use, it allows you to resize, crop and center an image to a specific width and height, it can suppert JPGs, PNGs and GIFs. Feel free to copy and paste it to your code:
function resize_imagejpg($file, $w, $h, $finaldst) {
list($width, $height) = getimagesize($file);
$src = imagecreatefromjpeg($file);
$ir = $width/$height;
$fir = $w/$h;
if($ir >= $fir){
$newheight = $h;
$newwidth = $w * ($width / $height);
}
else {
$newheight = $w / ($width/$height);
$newwidth = $w;
}
$xcor = 0 - ($newwidth - $w) / 2;
$ycor = 0 - ($newheight - $h) / 2;
$dst = imagecreatetruecolor($w, $h);
imagecopyresampled($dst, $src, $xcor, $ycor, 0, 0, $newwidth, $newheight,
$width, $height);
imagejpeg($dst, $finaldst);
imagedestroy($dst);
return $file;
}
function resize_imagegif($file, $w, $h, $finaldst) {
list($width, $height) = getimagesize($file);
$src = imagecreatefromgif($file);
$ir = $width/$height;
$fir = $w/$h;
if($ir >= $fir){
$newheight = $h;
$newwidth = $w * ($width / $height);
}
else {
$newheight = $w / ($width/$height);
$newwidth = $w;
}
$xcor = 0 - ($newwidth - $w) / 2;
$ycor = 0 - ($newheight - $h) / 2;
$dst = imagecreatetruecolor($w, $h);
$background = imagecolorallocatealpha($dst, 0, 0, 0, 127);
imagecolortransparent($dst, $background);
imagealphablending($dst, false);
imagesavealpha($dst, true);
imagecopyresampled($dst, $src, $xcor, $ycor, 0, 0, $newwidth, $newheight,
$width, $height);
imagegif($dst, $finaldst);
imagedestroy($dst);
return $file;
}
function resize_imagepng($file, $w, $h, $finaldst) {
list($width, $height) = getimagesize($file);
$src = imagecreatefrompng($file);
$ir = $width/$height;
$fir = $w/$h;
if($ir >= $fir){
$newheight = $h;
$newwidth = $w * ($width / $height);
}
else {
$newheight = $w / ($width/$height);
$newwidth = $w;
}
$xcor = 0 - ($newwidth - $w) / 2;
$ycor = 0 - ($newheight - $h) / 2;
$dst = imagecreatetruecolor($w, $h);
$background = imagecolorallocate($dst, 0, 0, 0);
imagecolortransparent($dst, $background);
imagealphablending($dst, false);
imagesavealpha($dst, true);
imagecopyresampled($dst, $src, $xcor, $ycor, 0, 0, $newwidth,
$newheight,$width, $height);
imagepng($dst, $finaldst);
imagedestroy($dst);
return $file;
}
function ImageResize($file, $w, $h, $finaldst) {
$getsize = getimagesize($file);
$image_type = $getsize[2];
if( $image_type == IMAGETYPE_JPEG) {
resize_imagejpg($file, $w, $h, $finaldst);
} elseif( $image_type == IMAGETYPE_GIF ) {
resize_imagegif($file, $w, $h, $finaldst);
} elseif( $image_type == IMAGETYPE_PNG ) {
resize_imagepng($file, $w, $h, $finaldst);
}
}
All you have to do to use it is call it like so:
ImageResize(image, width, height, destination);
E.g.
ImageResize("uploads/face.png", 100, 150, "images/user332profilepic.png");

JPEG Images Turn all black when converting from a PNG with 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.

Categories