Upload image without losing quality - php

I use this class to upload and resize images. The problem is that images have bad quality! I need to upload images without losing quality at all!
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
Can anyone please help?

one thing you can do is when you call to function save,
change quality parameter from 75 to 100 , when you call imagejpeg
quality is optional, and ranges from 0 (worst quality, smaller file) to 100 (best quality, biggest file). The default is the default IJG quality value (about 75).

I see a 75 as a default for the $compression parameter. You pass that as the quality parameter for imagejpeg. This is what probably generates the quality loss.

You save function defaults the quality value to 75. So either change it when you call it to 100 or change the default to 100. 100 is the best quality.

Related

image resizing png adding black colour in background

I am resizing images using the code below, but their is problem with resizing png images with transparent background that it fills the background with black color.
Below is the full code of image resizing:
function store_uploaded_image($html_element_name, $new_img_width, $new_img_height ,$size ,$target_dir) {
$target_file = $target_dir .'image-'.$size.'.png';
$image = new SimpleImage();
$image->load($_FILES[$html_element_name]['tmp_name']);
$image->resize($new_img_width, $new_img_height);
$image->save($target_file);
return $target_file; //return name of saved file in case you want to store it in you database or show confirmation message to user
}
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_PNG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
EDIT:
as #Marc B suggested, using imagealphablending and imagesavealpha before imagecopyresampled made it to work.
imagealphablending( $targetImage, false );
imagesavealpha( $targetImage, true );

Function to resize jpg file compresses it too

I have a script which resizes images on server side before loading it to the client side.
Issue with this script is it compresses the file too, and that ends up in bad quality images.
Have a look at the script:
Image_Resize.php
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=0, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,100);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
if ($this->image_type == IMAGETYPE_PNG){
imagealphablending($new_image, false);
imagesavealpha($new_image, true);
$transparent = imagecolorallocatealpha($new_image, 255, 255, 255, 127);
imagefilledrectangle($new_image, 0, 0, $width, $height, $transparent);
}
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
?>
Photo.php
<?php
require 'Image_Resize.php';
header('Content-Type: image/jpeg');
$imagenew=$_GET['id'];
$name=substr($imagenew,1);
if(file_exists($name)){
$image = new ResizeImage();
$image->load($imagenew);
$image->resize($_GET['width'], $_GET['height']); //25-width, 30-height
$image->output();
}
?>
I tried passing quality parameter to function imagejpeg in output function in Image_resize.php file. It's like this: imagejpeg($this->image,$filename,100);
But it's not working either(still outputs poor result than the original image). Anybody help?

Dynamically resample hotlinked images using php

I have an images directory, some with massive resolutions, so I'd like to serve a much lower resolution version if they get hotlinked and I'm also overlaying a repeating image (like a watermark) informing the viewer that the image is stolen and where they can find the genuine original.
I've got the resampling working fine but when I add the function for the no hotlink image overlay, it doesn't work. The thing is, I know the watermarking script works too, on it's own, because I've used it elsewhere in another file on the site. Unfortunately I can't tell what the error is as the hotlink test sites don't output errors, they just show an empty image placeholder, and my host's log files are all like greek to me.
This is the script I have at the moment:
<?php
ini_set('memory_limit','250M');
$path = $_SERVER['DOCUMENT_ROOT'].$_SERVER['REQUEST_URI'];
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=60, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
imagedestroy($image);
exit();
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
function nothot() {
$hotlink = imagecreatefrompng('hotlink.png');
$hw = imagesx($hotlink);
$hh = imagesy($hotlink);
$img_paste_x = 0;
$img_paste_x = 0;
while($img_paste_x < $this->getWidth()){
$img_paste_y = 0;
while($img_paste_y < $this->getHeight()){
imagecopy($image, $hotlink, $img_paste_x, $img_paste_y, 0, 0, $hw, $hh);
$img_paste_y += $hh;
}
$img_paste_x += $hw;
}
imagedestroy($hotlink);
}
}
header('Content-Type: image/jpeg');
$image = new SimpleImage();
$image->load($path);
$image->resizeToWidth(600);
$image->nothot();
$image->output();
?>
Thanks for your help.
Change:
imagecopy($image, $hotlink, $img_paste_x, $img_paste_y, 0, 0, $hw, $hh);
to:
imagecopy($this->image, $hotlink, $img_paste_x, $img_paste_y, 0, 0, $hw, $hh);
Also not sure about the way you get the $path, some checks on whether the image exists wouldn't go a miss.

How to change the name of file by which it is stored

I am using image upload and resize script from someones blog. It stores the name of file as resize.jpg .however i want to give unique names to them as data will go in database...I am very bad in using functions so please guide me.
<?php
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
?>
<?php
if( isset($_POST['submit']) ) {
include('SimpleImage.php');
$image = new SimpleImage();
$image->load($_FILES['uploaded_image']['tmp_name']);
$image->resizeToWidth(300);
$image->resizeToHeight(200);
$image->save('images/resize.jpg');
//$image->output();
} else {
?> <form action="" method="post" enctype="multipart/form-data">
<input type="file" name="uploaded_image" />
<input type="submit" name="submit" value="Upload" />
</form><?php
}
?>
Inside this block, you are saving every one as resize.jpg
$image->resizeToWidth(300);
$image->resizeToHeight(200);
$image->save('images/resize.jpg');
You can generate a unique name with uniqid() and optionally add a prefix onto it like img_. Your filenames will then look like:
'img_4e297753130db.jpg'
Start by generating a filename, saved in a variable.
$prefix = "img_"
$new_filename = uniqid($prefix) . ".jpg";
// Do your other processing
// ...
$image->resizeToWidth(300);
$image->resizeToHeight(200);
// Save with the new filename
// Note change to double quotes from single...
$image->save("images/$new_filename");
Later, when you're ready to store the filename in the database, it's still available in $new_filename
The image name is set in this line:
$image->save('images/resize.jpg');
You will need to determine how you want to name the output files, and modify that line to produce the desired output.
If you can provide more specific detail regarding your statement "i want to give unique names," please update your question.

Fix png transparency problem

I use this class to upload images on my server. The problem is that when I upload transparent png images, the transparent parts get black. Is there a way to keep transparency in png images?
class SimpleImage {
var $image;
var $image_type;
function load($filename) {
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=100, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
I don't beleive that this class can handle transparent PNGs. The PHP documentation on imagecopyresampled explains this.
You'll probably need to extend the class to use imagecolorallocatealpha.
Read for reference: http://php.net/manual/en/function.imagecreatetruecolor.php
I used this one to ramain the transparency of a png or gif images.
imagecolortransparent($this->imageResized, imagecolorallocatealpha($this->imageResized, 0, 0, 0, 127));
imagealphablending($this->imageResized, false);
imagesavealpha($this->imageResized, true);
You may need to use
imagealphablending($this->image, false);
imagesavealpha($this->image, true);
before imagepng
Solution can be found here:
PNG Transparency Resize with SimpleImage.php Class
it modifies a bit the class in order to allow transparencies in case of PNG and GIF images.

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