I'm working on an image resize script for php, and had a few questions..
Currently I'm pulling an external URL as the image, and don't really want to store the new image that is going to be re-sized on my server. Here is what I'm trying to do:
Have the script resize the image, than encode it the resized image in base64 on the fly. Now what I'm wondering is, would this be heavy on performance both doing the encode, and serving up the image with base64 rather than just the url? or would it be better to store the image rather than to store the base64 code for it?
Why are you encoding the resized image? Why not just output it directly. You don't need to save it to a file.
Some relevant lines from php function page:
// Content type
header('Content-type: image/jpeg');
// Resize
imagecopyresized($thumb, $source, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
// Output
imagejpeg($thumb);
To include it in the page you would do something like:
<img src="resizer.php?url=[encoded url here]" />
Related
I am trying to create an employee poster for a website that I develop. My goal is to take an image from a directory on the server of any file type (.png, .gif, .jpeg, etc.) and copy it onto another generate imaged that will then be outputted to the browser.
The problem is that I use:
$final_image = imagecreatefrompng("large_background.png");
for making the final image and for some reason if I add profile images with the type jpeg's, gif's, etc, (any type that isn't a jpeg) it doesn't work. The images never show up in the output. However, if I use png's it does work.
To solve this problem I tried converting the image to a png and then creating a png from it as shown in the code below. Unfortunately it doesn't work. Profile images still do not show up on the background.
// get image from database
$image_from_database = could be a .png, .jpeg, .gif, etc.
// get the image from the profile images directory
$path = "profile_images/".$image_from_database;
// create a png out of the image
$image = imagecreatefrompng(imagepng($path));
// add the $image to my larger $final_image (which is a png)
imagecopy($final_image, $image, $x, $y, 0,0, $height, $width);
imagepng($final_image, $ouput_url);
...
Can anybody tell me why this won't work? My profile images do not show up in the output of the final image.
My questions,
Is this line imagecreatefrompng(imagepng(...)); even possible? Essentially I want to convert an image of any type into a png and then create a png from it.
I'm just running a few local tests... The following works:
$src = imagecreatefromgif('test.gif');
$dest = imagecreatefrompng('test.png');
imagecopy($dest, $src, 0, 0, 0, 0, 100, 100);
header('Content-Type: image/png');
imagepng($dest);
imagedestroy($src);
imagedestroy($dest);
So does this:
$src = imagecreatefromstring(file_get_contents('test.gif'));
If you're still having trouble after trying the latter example, please update your question. The actual images you're using would be helpful, in addition to a functional code example.
After you read an image with a imagecreatefrom* function, it doesn't matter what format the original was.
imagecreatefrom* functions return an image resource. When the image is loaded you are using internal representation of the images and not PNG, JPEG or GIF images.
If the images are successfully loaded imagecopy should have no problems with them.
This code uses images in different formats and works without a problem:
$img = imagecreatefrompng('bg.png');
$png_img = imagecreatefrompng('img.png');
$jpeg_img = imagecreatefromjpeg('img.jpeg');
$gif_img = imagecreatefromgif('img.gif');
/* or use this, so you don't need to figure out which imagecreatefrom* function to use
$img = imagecreatefromstring(file_get_contents('bg.png'));
$png_img = imagecreatefromstring(file_get_contents('img.png'));
$jpeg_img = imagecreatefromstring(file_get_contents('img.jpeg'));
$gif_img = imagecreatefromstring(file_get_contents('img.gif'));
*/
imagecopyresampled($img, $png_img, 10, 10, 0,0, 100, 100, 200, 200);
imagecopyresampled($img, $jpeg_img, 120, 10, 0,0, 100, 100, 200, 200);
imagecopyresampled($img, $gif_img, 230, 10, 0,0, 100, 100, 200, 200);
header('Content-Type: image/png');
imagepng($img);
Your example
$image = imagecreatefrompng(imagepng($path));
is wrong.
imagepng is used to output an image resource as a PNG image. If you provide a path as a second argument a PNG image file is created, otherwise it's printed to the output like echo does.
What imagepng actually returns is a boolean, indicating, if the output was successful.
You are then passing that boolean to imagecreatefrompng which expects a filepath. This is obviously wrong.
I suspect you have a problem with loading images.
imagecreatefrom* functions return FALSE on failure and you should check, if you have any problems with that.
Maybe your image paths are relative to doc root and your working directory is different.
Or you have permission problem.
Or your images are just missing.
It's impossible to tell from your question.
UPDATE:
now I learned more I looked alot and modified I got this:
function show_image($image, $new_width, $new_height) {
//$this->helper('file'); why need this?
//$image_content = read_file($image); We does not want to use this as output.
list($old_width,$old_height) = getimagesize("$image");
//resize image
$image = imagecreatefromjpeg($image);
$thumbImage = imagecreatetruecolor($new_width, $new_height);
imagecopyresized($thumbImage, $image, 0, 0, 0, 0, $new_width, $new_height, $old_width, $old_height);
imagedestroy($image);
//imagedestroy($thumbImage); do not destroy before display :)
ob_end_clean(); // clean the output buffer ... if turned on.
header('Content-Type: image/jpeg');
imagejpeg($thumbImage); //you does not want to save.. just display
imagedestroy($thumbImage); //but not needed, cause the script exit in next line and free the used memory
exit;
}
when using this function I get a file, but I need to get a URL
I wanna be able to use:
<img src=" ... ">
Since you can't use GD on the server, a good option might be to handle it on the client side.
One idea that comes to mind is loading the image into an html5 canvas, and using that to manipulate the image characteristics before uploading it to the server.
This post talks about how you'd go about uploading image data straight from a canvas and saving it as an image on your server.
How to save a HTML5 Canvas as an image on a server
You also will likely need to take a look at the JavaScript File API to load the image into the canvas on the client side.
It's not necessarily an easy solution, but it might be your best shot without access to GD and stuff.
I've been trying to get transparency to work with my application (which dynamically resizes images before storing them) and I think I've finally narrowed down the problem after much misdirection about imagealphablending and imagesavealpha. The source image is never loaded with proper transparency!
// With this line, the output image has no transparency (where it should be
// transparent, colors bleed out randomly or it's completely black, depending
// on the image)
$img = imagecreatefromstring($fileData);
// With this line, it works as expected.
$img = imagecreatefrompng($fileName);
// Blah blah blah, lots of image resize code into $img2 goes here; I finally
// tried just outputting $img instead.
header('Content-Type: image/png');
imagealphablending($img, FALSE);
imagesavealpha($img, TRUE);
imagepng($img);
imagedestroy($img);
It would be some serious architectural difficulty to load the image from a file; this code is being used with a JSON API that gets queried from an iPhone app, and it's easier in this case (and more consistent) to upload images as base64-encoded strings in the POST data. Do I absolutely need to somehow store the image as a file (just so that PHP can load it into memory again)? Is there maybe a way to create a Stream from $fileData that can be passed to imagecreatefrompng?
you can use this code :
$new = imagecreatetruecolor($width, $height);
// preserve transparency
imagecolortransparent($new, imagecolorallocatealpha($new, 0, 0, 0, 127));
imagealphablending($new, false);
imagesavealpha($new, true);
imagecopyresampled($new, $img, 0, 0, $x, 0, $width, $height, $w, $h);
imagepng($new);
imagedestroy($new);
It will make a transparent image for you. Good Luck !
Blech, this turned out to ultimately be due to a totally separate GD call which was validating the image uploads. I forgot to add imagealphablending and imagesavealpha to THAT code, and it was creating a new image that then got passed to the resizing code. Which should probably be changed anyway. Thanks very much to goldenparrot for the excellent method of converting a string into a filename.
Do I absolutely need to somehow store the image as a file (just so that PHP can load it into memory again)?
No.
Documentation says:
You can use data:// protocol from php v5.2.0
Example:
// prints "I love PHP"
echo file_get_contents('data://text/plain;base64,SSBsb3ZlIFBIUAo=');
I have lots of jpeg images that are oversized (height, width), all with different sizes and different aspect ratios.
I'm showing them from a database like this:
<img src="<?php echo $img1; ?>" width="300" height="400">
What I'd like to have is some kind of php function to display a cropped version of the image like this:
cropjpeg('$img1');
For example, if the image is 600 W, 700 H, have php or GD show a cropped version around 300 W, 400 H starting from the top left hand of the image.
Some caveats:
I can't use CSS to do faux cropping. If you download this cropped image, it needs to be just that, the smaller cropped version.
I don't really want to create and save a new image, so I guess I need this to work "on the fly"
I tried imagecreatefromjpeg and imagejpeg, but it seems as though header('Content-Type: image/jpeg'); is not the right answer since there is more on the html page than just this 1 image
There is a lot of traffic on the site, so it has to tread lightly
Here's the best I found so far, but it uses the header('Content-Type: image/jpeg');
<?php
function cropjpeg($img, $x, $y, $width, $height,$grade=5)
{
// Create image instances
$src = imagecreatefromjpeg($img);
$dest = imagecreatetruecolor(400, 300);
// Copy
imagecopy($dest, $src, 0, 0, 20, 13, 400, 300);
// Output and free from memory
header('Content-Type: image/jpeg');
imagejpeg($dest);
imagedestroy($dest);
imagedestroy($src);
}
cropjpeg('images/bikini.jpg');
?>
Any ideas?
You cannot crop an image in the actual html page as it needs to be processed, that's if you don't want to save it on disk.
You can dump the crop script in a single PHP file with headers and call from HTML the script with path eg:
<img src="http://www.example.org/crop.php?i=bikini.jpg&x=13&y=20&w=400&h=300" alt="" />
and in script you can use
<?php
header('Content-Type: image/jpeg');
function cropjpeg($img, $x, $y, $width, $height,$grade=5) {
//......................
imagecopy($dest, $src, 0, 0, $x, $y, $width, $height);
//......................
}
cropjpeg('images/'.$_GET['i'], (int)$_GET['x'], (int)$_GET['y'], (int)$_GET['w'], (int)$_GET['h']);
?>
You should consider the aspect ratio, and search for a better crop script, you don't have to reinvent the wheel.
Use mod_rewrite to send requests for the relevant image file paths to a PHP script, which does the cropping and sends the image data back in response. It looks like a normal image tag on the page, but the images are really being served by your separate script.
The only issue is that you simultaneously don't want to save the cropped files, but have a lot of traffic so want to "tread lightly". You can't have both ways. If you don't want to re-crop the images on every request, you'll need to save the cropped versions so you can re-serve them on future requests.
Here is a page with a very complete tutorial with everything you need to do this using ajax included
crop with jquery and php
[http://www.skillcorp.com.ve][2]
[2]: http://www.skillcorp.com.ve here also more info relational
I have an image which i am going to be using as a background image and will be pulling some other images from the database that i want to show within this image. So if i am pulling only 1 image, i want the bottom part of the background image to close after the first image, if there are multiple images then i want it close after those images are shown. The problem with not using separate images is that the borders of the images have a design format and i cannot show them separately.
Take a look at this image . The design format of the right and left borders are more complicated than that to just crop them and use them. Any suggestions if there is any dynamic image resizing thing?
Yes there is. Look at the imageXXXX functions; the ones you are particularly interested in are imagecreate, imagecreatetruecolor, imagecreatefrompng, imagecopyresampled, imagecopyresized, and imagepng (assuming you're dealing with PNG images - there's similar load / save functions for jpeg, gif, and a few other formats).
You should try using the GD extension for PHP, especially have a look at imagecopyresized(). This allows you to do some basic image conversion and manipulation very easily.
A basic example that takes two GET parameters, resizes our myImage.jpg image and outputs it as a PNG image:
<?php
// width and height
$w = $_GET['w'];
$h = $_GET['h'];
// load image
$image = imagecreatefromjpeg('myImage.jpg');
// create a new image resource for storing the resized image
$resized = imagecreatetruecolor($w, $h);
// copy the image
imagecopyresized($resized, $image, 0, 0, 0, 0, $w, $h, imagesx($image), imagesy($image));
// output the image as PNG
header('Content-type: image/png');
imagepng($resized);
Have you tried PHPThumb? I used this class often and its pretty clean and lightweight. I used it here.