Indexhibit
Index + Exhibit

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Created by
Daniel Eatock
Jeffery Vaska
And You

Indexhibit was updated to version 2.1.4 on April 10, 2017.

How to create image upload hooks that generate thumbnails where ICC color profiles embedded?

 

Indexhibit version: Legacy
Thread is not resolved.

maxm
GERMANY
2 year(s) ago
Permalink Post

As PHP GD library doesn't copy the ICC color profiles, I do wish to insert a function after thumbnail files are generated to post-process them and copy the ICC profile from the source image.

  1. I think that inserting the thumbnail post-process hooks needs to be done in /lib/media.php, once for sys- files and once for th- files. That is function sys_thumb() and function upload_image().
  1. The idea is to insert this post-processing after line:
  2. $this->do_output($output_image, $this->image);
  3. and before line:
  4. imagedestroy($output_image);.
  1. I do need the <strong>source image location</strong>, that is path and filename. My idea is to use $this->input_image for that. And I need the generated <strong>resized thumbnail location</strong>, for which I use $this->image.

After making these changes, image uploading fails silently.

  1. Questions:
  2. 1. How to detect jpeg images? if ($this->filemime == 'jpg')?
  3. 2. Are the suggested hook insertion locations ok?
  4. 3. Are the suggested source and destination file locations ok?
  5. 4. How to turn on debugging output (all error messages)?

maxm
GERMANY
2 year(s) ago
Permalink Post

The image ICC manipulation library had some "throw new Exception" statements. After changing these to "echo" debugging became a lot easier. And right now the ICC color profiles remain embedded in the resized images and thumbnails.

maxm
GERMANY
2 year(s) ago
Permalink Post

Sharing with the community, what have I changed in legacy version of indexhibit (0.73) to keep the ICC profiles embedded in the thumbnails and resized images?

  1. 1. I downloaded an image ICC manipulation library from sourceforge.net/projects/jpeg-icc/
  2. 2. I extracted the zip file and copied file class.jpeg_icc.php to /ndxz-studio/lib/
  3. 3. I modified file /ndxz-studio/lib/media.php
  1. I modified class.jpeg_icc.php by searching for every throw new Exception statement and replaced it with an echo. That will save you time to figure out in case anything is wrong.
  1. The /ndxz-studio/lib/media.php modifications are:
  2. 4. insert require_once('class.jpeg_icc.php'); before class Media.
  3. 5. in function function upload_image( just before imagedestroy($output_image); are inserted these lines:
  4.             // copy ICC profile
  5.             if (($this->filemime == 'jpg') || ($this->filemime == 'jpeg'))
  6.             {
  7.                 $icc = new JPEG_ICC();
  8.                 $icc->LoadFromJPEG($this->path . $this->filename);
  9.                 $icc->SaveToJPEG($this->image);
  10.             }
  11. 6. in function function sys_thumb( just before imagedestroy($output_image); are inserted these lines:
  12.         // copy ICC profile
  13.         if (($this->filemime == 'jpg') || ($this->filemime == 'jpeg'))
  14.         {
  15.             $icc = new JPEG_ICC();
  16.             $icc->LoadFromJPEG($this->path . $this->filename);
  17.             $icc->SaveToJPEG($image);
  18.         }
 

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