[TYPO3-english] PDF Thumbnail Generation Problem

[Michael Brice]

INTRODUCTION:
Hello - I am new to TYPO3 and very excited about its feature rich capabilities. . .

I would like to share a recent discovery regarding resolution of a "PDF Thumbnail Generation Problem" in a shared hosting environment when using the TYPO3 file upload feature.

PROBLEM:
When PDF files are uploaded using the TYPO3 file upload feature, default duplicate error thumbnails were created with the "Thumbnail Not Generated!" error.

IMPACT:
The "PDF Thumbnail Generation Problem" may impact users where "All" PDF files are affected or where only "some" PDF files are affected.

SOLUTION: 
The solution is to determine the root cause and implementation of the following:

1) Run PHP test script to determine the hosting environment and configuration related to the image processing applications that perform thumbnail conversion.

2) Run PHP test script to test the PDF thumbnail "convert" function separate from the TYPO3 system using a standards compliant PDF test file with instructions.

3) Make required changes and re-test the TYPO file upload feature

DETAILS:
Any of the following issues could be the potential cause of the problem:

- Improper server installation or versions of ImageMagick and GhostScript (IM-GS)
- Older versions of ImageMagick and GhostScript (IM-GS) on the server
- Incorrect ImageMagick path configuration setting in TYPO3
- Incorrect or unknown hosting account absolute path in program coding 
- Corrupted, encrypted, or compressed PDF files.
- Compatibility of GhostScript with recent versions of PDF files

To help isolate the "PDF Thumbnail Generation Problem", Smargasy, Inc. >smargasy.com/<, a TYPO3 Certified Integrator, helped provide some coding to run PHP test scripts. The PHP test scripts were created to determine the hosting environment configuration and then that information was used for creating a test script to directly run the server image processing software (ImageMagick and GhostScript) without using TYPO3. A very important "standards compliant" PDF test file was created as the source file for conversion testing using the created conversion scripts. The standards compliant PDF test file (Smargasy_PDF-Thumbnail-Compatibility-Test-File.pdf" is also the detailed instructions for performing the testing. The test file and instructions are free for distribution and the direct download link (Hosted by Smargasy, Inc.) is:

>smargasy.com/fileadmin/media_data/community/Smargasy_PDF-Thumbnail-Compatibility-Test-File.pdf<

Although others may have thumbnail generation problems that are slightly different, the PDF test file is a great starting point and would have saved me many hours of troubleshooting.

Best Regards,
Mike Brice