Hi Markus,
Thanks for your reply and sorry for the long delay.
Hey, in your travels, have you seen any fixes to allow the TIFF module to
support writing with compression? It seems that the PIL always writes TIFF
files uncompressed and doesn't seem to support writing with compression. I
would love to find a fix for that, as well. Any help would be greatly
appreciated.
Thanks!
Gary
----- Original Message -----
From: Markus Kemmerling
To: Gary Bloom
Cc: Image-SIG@python.org ; [EMAIL PROTECTED]
Sent: Thursday, October 18, 2007 2:50 AM
Subject: Re: [Image-SIG] BUG: PIL DPI trouble - fix for TIFF files (PIL 1.1.6)
I would really like to see these fixes included in a next PIL release, if
there will be one. (I also would like to see an egg release, but that's a
different story.)
Note, that I posted a similar fix (combining Florian's and your's) to the
list a long time ago (july 2006). There is a small difference though, see below.
Maybe a test for these fixes should be added, but I can't see any TIFF image
tests at all in the PIL distribution.
Am 10.10.2007 um 16:18 schrieb Gary Bloom:
Here's a quick fix for the writing of the file, as well...
Before making the fix below, go to line 721 and change the '1' to a '2' !
721: ifd[RESOLUTION_UNIT] = 1
becomes
721: ifd[RESOLUTION_UNIT] = 2
Then make the changes listed below. This is consistent with those
changes. This is a quick and dirty fix that I have not tested extensively, but
it quickly allows me to read and write TIFF images with both the PIL and
Photoshop, and each can see the DPI as set by the other. It fixes the problem
I've had with PIL reading/writing TIFFs. Thanks, Florian!
Regards,
Gary Bloom
Sales Engineer
Sefas Innovation
www.sefas.com
============
[Image-SIG] BUG: PIL DPI trouble - fix for TIFF files (PIL 1.1.6)
Florian Höch lists+Image_SIG at hoech.org
Fri Oct 5 00:05:16 CEST 2007
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PIL only adds a dpi entry in the info dictionary if no resolution unit
is specified in the TIFF file. This seems to be because of a
misinterpretation of resolution unit values: they have a different
meaning than in a JPEG file. JPEG: 0 = None; 1 = inches; 2 = cm. TIFF: 1
= None; 2 = inches; 3 = cm (see
http://www.awaresystems.be/imaging/tiff/tifftags/resolutionunit.html and
http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/JPEG.html)
Here's a quick fix:
Open TiffImagePlugin.py and go to line 577. Change the code:
xres = getscalar(X_RESOLUTION, (1, 1))
yres = getscalar(Y_RESOLUTION, (1, 1))
if xres and yres:
xres = xres[0] / (xres[1] or 1)
yres = yres[0] / (yres[1] or 1)
resunit = getscalar(RESOLUTION_UNIT, 1)
if resunit == 2: # Inches
self.info["dpi"] = xres, yres
elif resunit == 3: # Centimeters
self.info["dpi"] = xres * 2.54, yres * 2.54When converting from inches
to centimeters, shouldn't you rather divide by 2.54 instead of multiplying?
else: # No absolute unit of measurement.
self.info["resolution"] = xres, yres
Regards,
Florian Hoech
_______________________________________________
Image-SIG maillist - Image-SIG@python.org
http://mail.python.org/mailman/listinfo/image-sig
Regards,
Markus Kemmerling
_______________________________________________
Image-SIG maillist - Image-SIG@python.org
http://mail.python.org/mailman/listinfo/image-sig
