[Image-SIG] Re: help wanted: new TiffImagePlugin needs testing

Roger Burnham rburnham@cri-inc.com
Tue, 15 Jun 1999 06:40:23 -800

On 13 Jun 99, at 21:46, Fredrik Lundh mused: 

> An almost entirely rewritten TiffImagePlugin.py can be 
> found at: 
>     http://www.pythonware.com/madscientist/tiff-990613.zip 
> this version can read and write all standard PIL modes 
> (including F and I), and seems to work just fine with all 
> other apps I've gotten around to test it with. 
> if you can, why not take it on a test drive, and report 
> your findings back to this list.  I'll check back on Wed- 
> nesday. 

Thanks Fredrik,  nice work! 

I tested this only on 16-bit grayscale images, using my modified _imaging.dll. 

To the OPEN_INFO, I added: 

    (1, 1, (16,), ()): ("W", "L;16B"), 

and to SAVE_INFO, I added: 

    "W": ("W", 1, 1, (16,), None), 

and then tested 5 images, written by a variety of other tiff writers (PhotoShop  
4, ImagePro 4, another CRI C++ app, MetaMorph, and the previous version of  

The test was to read the image, write it out, read that image back in, and then  
test that all the pixel values (original vs written/read) were the same...all  

The only thing I see missing is that many of the original tags are not written  
out in the saved tif: 

tag: ImageDescription (270)  
tag: Software (305)  
tag: DateTime (306)  
tag: unknown (33628)  

Fredrik, have you had a chance to look at the 16bit mods I sent you?  I  
understand you probably do not have time to fold this into 1.0 final, so, if you  
could comment on what I did send you, I'll fold it back into 1.0 final with your  
suggested changes.  In particular, I know I need some guidance on implementing  
the packers/unpackers:  What I did was somewhat blind copying/modifying of  
existing ones, not entirely sure I know what I'm doing and will be happy to  
change it to your satisfaction!  I'd also volunteer to add the tag save  


Roger Burnham   
Cambridge Research & Instrumentation   
PGP Key: http://www.nai.com/default_pgp.asp   
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