Accessing to variable from memory - php

I created an image class, it loads and resizes image, then crops and lastly watermarks it.
For last step, I would like to add IPTC data to the this image. For what I know there is only iptcembed function to accomplish this. The problem is iptcembed needs the path of image as parameter. I'm keeping image as object before using it to render views.
$content = iptcembed($data, "./image.jpg");
I do not want to save image to storage just to create a path for iptcembed but I couldn't find another way to add IPTC data to the image.
Is there any way (or function) to access to this object from memory instead of saving and loading from storage?

You could use php://memory to have a file handle that reference in-memory data instead of data written to a file.
Credit goes to this original answer

I use CFX_OpenImage to read and write IPTC_ data in .jpg files using ColdFusion Language versions 8 thru 11. I also use CFX_OpenImage for image resize and rotation.
For more CFX_OPENIMAGE INFO go to http://www.kolumbus.fi/jukka.manner/cfx_openimage/
The software download includes a good manual of at least 65 pages.

Related

Proper way to store temporary image files for PHP

I have an image resource that is manipulated with imagecopyresampled. I need to pass that image to a set of methods that expect a string input, not a resource. But I don't need to store the file locally.
Is this the proper way:
Store the image with imagepng and imagejpeg
Pass string (filename) to the methods
Destroy the stored file with #unlink
Is that right? Seems sloppy.
Note: the image is not coming from a file upload and hence can't be accessed with $_FILES["Filedata"]["tmp_name"]
I took a look at the Amazon S3 PHP API:
http://docs.amazonwebservices.com/AWSSDKforPHP/latest/index.html#m=AmazonS3/upload_part
I assume you are using something like the upload_part method that takes a string filename. In that case, unless you plan to modify their library, you will need to store the file to disk and pass them the filename so they can read the file and perform the upload.
Besides the steps mentioned in your question you can take a look at imagedestroy to make sure you are freeing up the memory for your image resource after it is written to disk with imagepng. And then, as you stated, you can delete your temp file with unlink after your upload is complete.
I agree, it does seem a bit wasteful, but in this case necessary since the API doesn't seem to provide an alternative.

Is there a way with PHP to access a file on a server and save only the first half of the file?

I want to give users a preview of certain files on my site and will be using scribd API. Does anyone know how I can access the full file from my server and save the file under a different name , which I will then show to users..Can't think of a way to do this with PHP for .docx and image files...Help is much appreciated.
For "splitting" images, use an image processing library like gd to crop the image (lots of examples to be found on how to do that all over the place). For Word documents, use a library like PHPWord (or one of the other myriad such libraries) to open the document, remove/extract as much text as you need, then save that into a new Word file.
For other file types, find the appropriate method that allows you to manipulate that format, then do whatever you need to do with it.

PHP image thumbnail performance?

I've recently started trying to increase my sites performance. One of the biggest obstacles I have are the number of thumbnails being displayed.
I currently use the full size image and scale it down by defining a height/width value in the img tag. This doesn't seem very efficient so my question is whats the recommended way to display thumbnails? Should I maintain a second table in the DB for thumbnails or is there a better solution?
Processing images takes its (cpu) toll, you should better avoid it where possible.
My advice:
Create the thumbnails while uploading the images into separate image files, this way you can determine when to create/resize them - and not during runtime.
If you want the links to the thumbnails in a separate database field or derive it from the original name, is entirely up to you - both ways work.
This makes additional performance boosters easier to implement too (p.e. caching).
I've implemented a similar process in a php based project, its a good way to scale out. In my case, I am creating the thumbnails nightly via cron, because system load is very low in that time.
If using an uploader to get the images on your website, have PHP resize the original image and upload both the original and a smaller thumb with some kind of prefix in the name.
This way you can easily get the images from your database and just use "filename.jpg" for your normal images and "thumb_filename.jpg" for your thumb.
Same can be done without an uploader of course but you'd have to manually create/upload the thumbnails.
For example create seperate folder in images call it thumnails (images/thumbnails) add there put files prefixed with file size for ex: "original_file_name_200X200.jpg", store on database "original_file_name" and extension "jpg" to seperate fields (name, ext) then when you need to display it select name add size prefix and add extension you get /images/thumbnails/file_200X200.jpg this way you can add later more sizes leaving original untouched.
You are looking for something like what can be found here: http://dtbaker.com.au/random-bits/php-simple-image-resize-thumbnail-generator.html (this turns all images into jpegs)
Like #martincarlin87 stated - Just need to add a check to see if it exists in the thumbnail directory and either send the information or create and send it through. This can be turned into a function as well.
I use phpTumb to create thumbnails on the fly.
You could also use it while uploading a picture to change its dimesions.
It has many other features. Check it out.
you could use a program like imagemagick to make proper thumbnails.
If its your personal site you could batch resize (theres a powertool for xp that does this) and then upload to a 200 directory and change your code. Obviously this relies on you uploading the images.
imagemagick will need to be installed on the server but will resize and allow you to play with the size of the images

Resize image using PHP from an external image URL

I'm creating a web app that allows users to specify an image url to display an image along with their submission.
To avoid some potentially large images and odd sizes, i'd like to use PHP to limit/resize the image before it gets output to the browser (I know i could use max-width in CSS but this is unnecessary downloading)
Is this possible?
PHP has a library named GD. It's fairly easy to check the size of an image with the getimagesize() function.
You can find the complete code for it with 2 module/extensions: http://www.fliquidstudios.com/2009/05/07/resizing-images-in-php-with-gd-and-imagick/
a comparison of them can be found here: http://dreamfall.blogspot.com/2008/02/php-benchmarks-gd-vs-imagemagick.html which may be of use if you want optimize features.

How to resize linked images dynamically in PHP?

On my site I have given an option to user to choose thier profile image
Type link of an image
Image is a url link, and first I want it to resize to 400x300 (image's original size doesn't matter), and then display it on my web page.
Something like below:
<img src="http://mywebsite.com/resize.php?image=http://someotherurl.com/upload/image2.jpg&width=400&height=300" />
anyone knows this kind of script, please tell me how to solve this issue.
Thanks
A recent post:
https://stackoverflow.com/questions/1302464/php-image-resize-my-upload-script
has some code and comments that may give you some pointers. Otherwise may I suggest
http://www.white-hat-web-design.co.uk/articles/php-image-resizing.php.
Good luck!
If you have the GD extenstion, you can use imagecopyresampled (the documentation also features some examples). However, if the image to be resized is large and there is a low memory limit on your server, you may run out of memory.
I don't have ready to use source code, but it should look like:
Load image pointed by image parameter into object of ImageMagick (or other graphics library).
Resize it.
Send content to output stream.
Optionally you could:
Check if loaded file is image (plus other validation checks).
Save resized image on disk and serve it from disk next time (if you do it often).
Check docs of you favorite graphics library used in PHP for details.
Good luck!
Use the Class called - class.upload.php.
Find it at: PHP Classes
We use it at all times in many of our work.
The name is deceptive but actually it is an uploader as well as image processor. It has a very big list of functionality for resizing images, adding text to images, converting formats, etc. etc.
There is sample code which shows how to read an Image from server, modify it and finally send it directly to browser without having to create a temp file on server.
HTH

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