I am using html5 file api to preview a image in browser and then saving it to database as base64 string using ajax.
I need to reduce the quality in order to resize the image.
<?php
$img = $_POST['img'];
$i = explode(",",$img);
$img = $i[1];
$img = imagecreatefromstring[$img];
$rimg = imagejpeg($img,XXXXXXX, 60);
?>
xxx=> how could I turned it back to base64?
thanks in advance.
From http://php.net/manual/en/function.imagejpeg.php
/*
* imageXXX() only has two options, save as a file, or send to the browser.
* It does not provide you the oppurtunity to manipulate the final GIF/JPG/PNG file stream
* So I start the output buffering, use imageXXX() to output the data stream to the browser,
* get the contents of the stream, and use clean to silently discard the buffered contents.
*/
ob_start();
switch ($image_type)
{
case 1: imagegif($tmp); break;
case 2: imagejpeg($tmp, NULL, 100); break; // best quality
case 3: imagepng($tmp, NULL, 0); break; // no compression
default: echo ''; break;
}
$final_image = ob_get_contents();
ob_end_clean();
return $final_image;
or save to the file, then load the file as binary stream, base 64 the binary and delete the file
Related
Following code:
class FilesController extends Controller {
public function icon($fileId) {
$this->uses("FileAttachment");
$FA = new FileAttachment($fileId);
$fnth = $FA->path . 'th___' . $FA->filename;
$this->View->render = false;
if (file_exists($fnth)) {
$imageinfo = getimagesize($fnth);
switch ($imageinfo[2]) {
case IMAGETYPE_JPEG:
$image = imagecreatefromjpeg($fnth);
Header("Content-type: image/jpg");
imagejpeg($image);
break;
case IMAGETYPE_GIF:
$image = imagecreatefromgif($fnth);
Header("Content-type: image/gif");
imagegif($image);
break;
case IMAGETYPE_PNG:
$image = imagecreatefrompng($fnth);
//Header("Content-type: image/png");
imagepng($image);
break;
case IMAGETYPE_BMP:
$image = imagecreatefromwbmp($fnth);
Header("Content-type: image/bmp");
imagewbmp($image);
break;
}
}
imagedestroy($image);
}
}
produces broken images. The image is shown in a browser just as a broken one. The file exists, otherwise there would come nothing. My Windows shows the pictures correctly. What can be the cause?
PS. If I remove Header, the browser displays the image's binary content, so it actually looks OK...
Your code is rather pointless - you're forcing PHP (and gd) to do a bunch of useless work to load up the file, decompress it into memory, and then recompress it for output.
Why not simply have:
$info = getimagesize($path_to_file);
header('Content-type: ' . $info['mime']);
readfile($path_to_file);
?
As for your code, check the entire output of the function. If there's ANY php warnings/errors being produced, they'd get embedded in the output and general cause "corrupt" images.
imagecreatefromgif(); //returns an image resource
Have you tried to add at the bottom ?
readfile($image); //reads a file and writes it to the output buffer.
Is it possible to transform a .jpg, .jpeg or .gif image to .png in php without saving the image in your computer?
Something like:
function read_image($filename, $extension) {
switch($extension) {
case '.png':
$image = imagecreatefrompng($filename);
break;
case '.jpg': case '.jpeg':
$unTransformed = imagecreatefromjpeg($filename);
$image = transform($unTransformed);
break;
case '.gif':
$unTransformed = imagecreatefromgif($filename);
$image = transform($unTransformed);
break;
return $image;
}
}
function transform($unTransformed) {
// Some magic here without actually saving the image to your machine when transforming
return $transformed;
}
I honestly couldn't find an answer for this. Also note that GD is mandatory.
Using output buffering and capturing the output of imagepng should work, like this:
function transform($unTransformed) {
ob_start();
imagepng($unTransformed);
$transformed = ob_get_clean();
return $transformed;
}
Of course, this is assuming you actually want a variable containing a png bytestream of your image file. If the only purpose is to output it anyways, don't bother and do as Marty McVry suggests.
Directly from the PHP manual: (imagepng()-function, which outputs a PNG image to either the browser or a file)
header('Content-Type: image/png');
$transformed = imagepng($untransformed);
You might encounter a problem sending the headers along, so it's possibly necessary to output the headers somewhere else or transform the stream created by imagepng to a base64-string and display the image like that, depending on the rest of your code.
Our server is saving EXIF data to every file saved with imagejpeg(). As far as I know, this is not the default behavior (or even possible, from what I've read). But, it is occurring, and due to the FileDateTime information being included (and using the time of save), it is breaking functionality in our upload/approval system (md5_file() returns a different value for the exact same image due to FileDateTime always being different).
Is there a way to prevent imagejpeg() from saving EXIF data for images by default?
Server Information
CentOS 5
Parallels Plesk Panel 10.4.4
GD Version: bundled (2.0.34 compatible)
PHP 5.3
Code
<?php
public function upload_book_cover($book, $cover, $filename = NULL, $approved = NULL){
global $c_consummo, $user;
$approved = bool($approved, true, true);
if(filesize($cover)>5242880){
return false; // Too large;
}
$max_width = 450;
$cover_info = getimagesize($cover);
if(!$this->is_valid_book_cover_type($cover_info['mime'])){
return false; // Invalid image type
}
$width = $cover_info[0];
$height = $cover_info[1];
if($width<200){
return false; // Too small
} elseif($width>1500){
return false; // Too wide
}
$original_cover = false;
switch($cover_info[2]){
case IMAGETYPE_GIF:
$original_cover = imagecreatefromgif($cover);
break;
case IMAGETYPE_JPEG:
$original_cover = imagecreatefromjpeg($cover);
break;
case IMAGETYPE_PNG:
$original_cover = imagecreatefrompng($cover);
break;
case IMAGETYPE_BMP:
$original_cover = imagecreatefrombmp($cover);
break;
}
if(!$original_cover){
return false; // Unsupported type
}
if($width>$max_width){
$new_width = $max_width;
} else {
$new_width = $width;
}
$new_height = round($height*($new_width/$width));
$new_cover = imagecreatetruecolor($new_width, $new_height);
if(!$new_cover){
return false; // Could not create true color image
}
if(!imagecopyresampled($new_cover, $original_cover, 0, 0, 0, 0, $new_width, $new_height, $width, $height)){
return false; // Could not copy image
}
if(!imagejpeg($new_cover, $cover, 100)){
return false; // Image could not be saved to tmp file
// This is adding *new* EXIF data to images by itself
}
$file_hash = md5_file($cover);
$duplicate_book_cover = $this->find_duplicate_book_cover($book, $file_hash);
if($duplicate_book_cover){
return $duplicate_book_cover;
}
$file_id = $c_consummo->upload_file($cover, $filename);
...
}
It looks like you have tried several things here, but lets try one more.
Do you EVER need EXIF information in your application?
If not lets take out support for EXIF and see if that completely removes it.
If it does not remove it, then perhaps the functions are reading it from the existing photos and then just blindly including it in the file that is written.
You can know for sure by printing out the EXIF information at each step of process
No idea why EXIF data is being written - so the following may help you remove it.
One suggestion is to run something as a command on the server - it will need some installation: http://hacktux.com/read/remove/exif - then run throuhg EXEC from PHP.
There's also solution posted here that uses ImageMagick if you also have that installed (or cen get it installed: Remove EXIF data from JPG using PHP (but note warning about colour)
Otherwise, the other suggestion is as above, try turning off the EXIT extension.
Sorry if they don't help, but you did ask for any suggestions.
Apparently, GD doesn't like when the path to the input / output file is the same, but the credit isn't mine. To fix, use a new (tmp) file to save the newly created image to:
<?php
...
if(!imagecopyresampled($new_cover, $original_cover, 0, 0, 0, 0, $new_width, $new_height, $width, $height)){
return false; // Could not copy image
}
// Create a tmp file.
$cover_new = tempnam('/tmp', 'cover-');
// Use $cover_new instead of $cover
if(!imagejpeg($new_cover, $cover_new, 100)){
return false; // Image could not be saved to tmp file
}
// Use $cover_new instead of $cover
$file_hash = md5_file($cover_new);
$duplicate_book_cover = $this->find_duplicate_book_cover($book, $file_hash);
if($duplicate_book_cover){
return $duplicate_book_cover;
}
// Use $cover_new instead of $cover
$file_id = $c_consummo->upload_file($cover_new, $filename);
...
Read this, maybe it will help:
http://www.php.net/manual/en/function.imagecreatefromjpeg.php#65656
and this:
http://www.sentex.net/~mwandel/jhead/usage.html
You could possibly convert the jpeg to a gif first, then convert the gif back to a jpeg. In doing so, my understanding is that you would destroy the EXIF data. It's a hack, but it should work.
The only thing that spring to mind is, that you could ignore the EXIF data and just make your hash from something else? My suggestion would be to try either hashing the raw output without saving to a file (here outputting in gif format -which makes a smaller, 8-bit image for performance- to an output buffer and hashing the buffer content)
if(!imagecopyresampled(...)) {...}
ob_start();
imagegif($new_cover);
$file_hash = md5(ob_get_contents());
ob_end_clean();
if(!imagejpeg($new_cover, $cover, 100)) {...}
Or you could build a string containing only the pixel information and hash that (here done by accessing each pixel and appending its value to a string, in reverse for performance)
$pixels = '';
for($x=$new_width-1; $x>=0; $x--) {
for($y=$new_height-1; $y>=0; $y--) {
$pixels .= imagecolorat($new_cover, $x, $y);
}
}
$file_hash = md5($pixels);
For performance, you could also choose only to take samples from the image, as this should work just as well or maybe even better (here sampling every 5th pixel of every 5th row)
$pixels = '';
for($x=$new_width-1; $x>=0; $x-=5) {
for($y=$new_height-1; $y>=0; $y-=5) {
$pixels .= imagecolorat($new_cover, $x, $y);
}
}
$file_hash = md5($pixels);
I hope some of this will work (as I can't test it right now) or at least will help you find the way that works for you :)
This is a bit of a hack, but it will work, just do this after your switch() statement:
$original_cover = imagerotate($original_cover,360,0);
GD will strip any EXIF data out, as it doesn't support it.
You could try using imagecreatefromjpeg on the image created with imagejpeg and replacing with the newly created one.
$res = imagecreatefromjpeg($filename) to load the image, then imagejpeg($res, $filename, QUALITY)to rerender it.
You can use imagemagick too:
$img = new Imagick($image);
$img->stripImage();
$img->writeImage($image);
$img->clear();
$img->destroy();
Your PHP must be compiled in with --enable-exif.
Try to disable globally EXIF functionality by recompiling PHP without this option.
I have a question about the images displaying using a function getImage_w($image,$dst_w), which takes the image URL ($image) and the destination width for this image ($size). Then it re-draws the image changing its height according to the destination width.
That's the function (in libs/image.php file):
function getImage_w($image,$w){
/*** get The extension of the image****/
$ext= strrchr($image, ".");
/***check if the extesion is a jpeg***/
if (strtolower($ext)=='.jpg' || strtolower($ext)=='.jpeg'){
/***send the headers****/
header('Content-type: image/jpeg');
/**get the source image***/
$src_im_jpg=imagecreatefromjpeg($image);
/****get the source image size***/
$size=getimagesize($image);
$src_w=$size[0];
$src_h=$size[1];
/****calculate the distination height based on the destination width****/
$dst_w=$w;
$dst_h=round(($dst_w/$src_w)*$src_h);
$dst_im=imagecreatetruecolor($dst_w,$dst_h);
/**** create a jpeg image with the new dimensions***/
imagecopyresampled($dst_im,$src_im_jpg,0,0,0,0,$dst_w,$dst_h,$src_w,$src_h);
imagejpeg($dst_im);
}
In a file imagetest.php I have this code portion:
<?php
require 'libs/image.php';
echo '<h1>HELLO WORLD : some html</h1>
<img src="'.displayImg_w('http://www.sanctius.net/wp-content/uploads/2010/05/Avatar-20.jpg',200).'">
';
In the past, I used to write the URL with $_GET paramers defining the image. But now , I want to use the function directly in my code.
The problem is that the image is displaying correctly, but the Hello World HTML code is not translated by the browser (I know that the header are already sent by the first code) But I want to know how to display the image correctly without affecting the html code. and also without using get parameters that change the URL of the image to this undesired form :
libs/image.php?image=http://www.example.com/image&width=200
After my earlier, totally wrong answer, I hope to make up for it with this. Try this code:
<?php
function getImage_w($image,$w){
// Get the extension of the file
$file = explode('.',basename($image));
$ext = array_pop($file);
// These operations are the same regardless of file-type
$size = getimagesize($image);
$src_w = $size[0];
$src_h = $size[1];
$dst_w = $w;
$dst_h = round(($dst_w/$src_w)*$src_h);
$dst_im = imagecreatetruecolor($dst_w,$dst_h);
// These operations are file-type specific
switch (strtolower($ext)) {
case 'jpg': case 'jpeg':
$ctype = 'image/jpeg';;
$src_im = imagecreatefromjpeg($image);
$outfunc = 'imagejpeg';
break;
case 'png':
$ctype = 'image/png';;
$src_im = imagecreatefrompng($image);
$outfunc = 'imagepng';
break;
case 'gif':
$ctype = 'image/gif';;
$src_im = imagecreatefromgif($image);
$outfunc = 'imagegif';
break;
}
// Do the resample
imagecopyresampled($dst_im,$src_im,0,0,0,0,$dst_w,$dst_h,$src_w,$src_h);
// Get the image data into a base64_encoded string
ob_start();
$outfunc($dst_im);
$imgdata = base64_encode(ob_get_contents()); // Don't use ob_get_clean() in case we're ever running on some ancient PHP build
ob_end_clean();
// Return the data so it can be used inline in HTML
return "data:$ctype;base64,$imgdata";
}
echo '<h1>HELLO WORLD : some html</h1>
<img src="'.getImage_w('http://www.sanctius.net/wp-content/uploads/2010/05/Avatar-20.jpg',200).'" />
';
?>
This basically is not possible. The webbrowser requests the HTML page and expects HTML. Or it requests an image and expects an image. You cannot mix both in one request, just because only one Content-Type can be valid.
However, you can embed the image in HTML using data URI:
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4/8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==" alt="Red dot">
Be aware that the base64 encoding is quite ineffective, so make sure you definitly compress your output, if the browser supports it, using for example gzip.
So for you it likely looks like the following:
echo '<img src="data:image/jpeg;base64,' . base64_encode(displayImg_w('http://www.sanctius.net/wp-content/uploads/2010/05/Avatar-20.jpg',200)) . '">';
And make sure displayimg_w() does not output a header anymore.
Furthermore, displayimg_w() needs to be adjusted at the end to return the image data as string rather than direct output:
ob_start();
imagejpeg($dst_im);
return ob_get_flush();
I have a iPhone app that uploads pictures to my server. One major issue I am having is a rotating one.
For some reason if I upload a picture from my iPhone, some pictures will automatically rotate. The one's that do get rotated are the ones in portrait mode. I have no code in my script that rotates the images.
How does a server exactly process tall images? Should I modify my php file to check to rotate it ahead after it automatically rotates? Should I code something in my iPhone app that will check this?
Any help is appreciated!
PS: If you need code, feel free to ask!
Some pictures(jpg) have exif data that tells the position the camera was when the picture was shot.
Take a look at http://www.php.net/manual/en/function.exif-read-data.php#76964
You may rotate the pictures server-side like this
Or a better way is to use this library
https://github.com/Intervention/image
And simply use like this-
$img = Image::make('foo.jpg')->orientate();
More can be found here.
When you take a picture your phone saves any rotation metadata in EXIF headers. When you upload the image to your server, that metadata is still sitting there but it's your job to apply it to the image to rotate it (if you want). In PHP you can use a function called exif_read_data:
function correctImageOrientation($filename)
{
$exif = exif_read_data($filename);
if ($exif && isset($exif['Orientation'])) {
$orientation = $exif['Orientation'];
if ($orientation != 1) {
$img = imagecreatefromjpeg($filename);
$deg = 0;
switch ($orientation) {
case 3:
$deg = 180;
break;
case 6:
$deg = 270;
break;
case 8:
$deg = 90;
break;
}
if ($deg) {
$img = imagerotate($img, $deg, 0);
}
imagejpeg($img, $filename, 95);
}
}
}
To use it simply call the function after you save the file. For more info and an additional PHP solution see the original source.