Re: Cannot Load Pixel Information From PNG Image
Karol Krizka <[email protected]>
| Newsgroups | gmane.comp.python.image |
|---|---|
| Message-ID | <[email protected]> |
On Wed, Jan 5, 2011 at 11:23 PM, Joao S. O. Bueno <[email protected]> wrote: > On Thu, Jan 6, 2011 at 3:06 AM, Karol Krizka <[email protected]> wrote: >> Hi there, >> >> I have a PNG file for which PIL 1.1.7 cannot seem to load the pixel >> values. It returns an integer for all of them instead of a touple. The >> script that I use to test this is very simple: >> >> import Image >> im=Image.open('house.png') >> print im >> data=im.load() >> print data >> print data[149,136] >> > > It just lookslike you have an indexed image, instead of an RGB one - > Just print out your > "im.mode" to get shure - > print im.mode 'L' Hmm, that seemed to have been the problem... I guess because this image only had greyish values (all RGB components were equal), ImageMagick decided that it would be best to create an grayscale PNG. Thank you for your help! > Proper parameter passing to imagemagick can convert it to a proper RGB > .png file. > For those interested, I now managed to create an RGB image using the following command: convert house.ppm png24:house.png > js > -><- >> The output of it is: >> <PngImagePlugin.PngImageFile image mode=L size=300x200 at 0x800DD0> >> <PixelAccess object at 0x641150> >> 97 >> >> I should note that the point (149,136) contains a pixel of colour >> (97,97,97). However when I change the colour at that point to >> (128,0,1), I get a value of 160. >> >> The PNG image was created by converting a PPM file (which PIL has no >> trouble reading) using ImageMagick's convert utility. PIL has no >> trouble reading other images created using the same method. My image >> viewing programs (xv, gwenview) have no trouble opening this >> problematic PNG file. I've attached the image to this email. >> >> The PIL version that I used is 1.1.7. It is the one in Gentoo Linux >> repositories. I also tried it with PIL that comes with Ubuntu Maverick >> 10.10 with the same results. >> >> >> -- >> Cheers, >> Karol Krizka >> http://www.krizka.net >> >> _______________________________________________ >> Image-SIG maillist - [email protected] >> http://mail.python.org/mailman/listinfo/image-sig >> >> > -- Cheers, Karol Krizka _______________________________________________ Image-SIG maillist - [email protected] http://mail.python.org/mailman/listinfo/image-sig