Thanks a lot Larry. That indeed does help! You see,
I have a strange type of requirement wherein I have to
generate image files of a particular resolution having
as large a file size as possible.
 Initially I was trying this by getting a high quality 
jpeg or bmp file, and converting this *without* any
options to PIL's Image.save. I was only partly successful.
For instance, I need a 352x288 jpeg of 300-350 KB size,
but I am about 200 KB short. Then I tried a different
approach - creating an image in PIL from scratch and
using ImageDraw's methods to go on adding lines, points 
etc until the filesize came close to what I wanted. But 
I found the size saturating at a point (far less than
the filesize I wanted though).
 Is there a better way of doing what I want ?

Thanks for the help mate!
Rajorshi


On Wed, 21 Jul 2004 13:57:13 -0500
"Larry Bates" <lbates@[...].com>  wrote:

>  Since PIL cannot (at the current time) support compressed
>  TIFF images, you cannot reduce their size by any options
>  from within PIL.  When I need to produce compressed TIFF
>  images, I use external program like tiffcp to handle the
>  compression (of course I do it by calling it from within
>  my Python program via os.system() call).
>  
>  I normally look into the source code for each different 
>  PIL plug-in to see what options are available.  The files
>  will be in the format ???ImagePlugin.py and are normally
>  located in /lib/site-packages/PIL subdirectory.
>  
>  Below is a snippet of code that shows the keywords for
>  JPEG plug-in:
>  
>      # get keyword arguments
>      im.encoderconfig = (
>          im.encoderinfo.get("quality", 0),
>          im.encoderinfo.has_key("progressive"),
>          im.encoderinfo.get("smooth", 0),
>          im.encoderinfo.has_key("optimize"),
>          im.encoderinfo.get("streamtype", 0),
>          dpi[0], dpi[1]
>          )
>  
>  This means he understands quality, progessive, smooth,
>  optimize, and streamtype keywords.  The only one I've
>  ever actually used it quality.
>  
>  HTH, Larry Bates
>  
>  
>  -----Original Message-----
>  From: Rajorshi Biswas [mailto:rajorshi@[...].com]
>  Sent: Tuesday, July 20, 2004 6:19 AM
>  To: image-sig@[...].org
>  Subject: [Image-SIG] generating images of different sizes
>  
>  
>  Hi,
>   This is my first post to the image-sig mailing list, so
>  hello to you all.
>   My knowledge of different file formats is somewhat limited.
>  What I have to do is essentially this : Given a resolution
>  (such as 352x288) and a file-size (such as 300KB), I have
>  to generate images using PIL of the following formats:
>  [ jpeg, gif, wbmp, bmp, png, tiff ]. 
>   I have achieved the first part, that is I can, starting
>  from a jpg image, generate all the other types with any
>  resolution (by resizing and using PIL's Image.save). But
>  I have no control over file size.
>   To do that I found that there's a variant of the Image.save
>  method that takes in a third parameter:
>  Image.save( filename, format, options ).
>   The PIL manual says that 
>  "Keyword options can be used to provide additional 
>  instructions to the writer. If a writer doesn't recognise 
>  an option, it is silently ignored. The available options 
>  are described later in this handbook."
>   Could someone please tell me what these options are ?
>  I seem to be unable to find the 'options' in the manual.
>  If it is not there, could someone tell me,
>  
>  1] What i need to do to reduce the size of the tiff files
>  I generate, what options I need to add to the call
>  Image.save('a.tiff') .
>  
>  2] Same for bmp files.
>   
>   That's a lot of queries for the first post! Please help!
>  
>  Thanks.
>  Rajorshi
>  
>  
>  
>  
>  
>  


-- 
-----------------------------------

Rajorshi Biswas

Trainee, Alumnus Software Ltd.
INFINITY, Tower II, 2nd Floor.
Plot - A3, Block - GP, Sector V
Salt Lake City, Kolkata 700 091
West Bengal, India

Phone     : +91 33 2357 5626/27/28 
Extension : 357/355
Alternate : rajorshi@[...].fm
Website   : http://www.rajorshi.tk

-----------------------------------


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