4 Replies Latest reply on Jan 13, 2014 5:17 PM by Chris Cox

    Problems opening a TIF with 14.828x18.446px (26,9MB)

    Felix Fabian

      Hi there,

       

      I'm trying to open some TIF-files coming from a GIS.

      These files are 14.828x18.446 pixel size with only 26,9MB file size.

      The "out of RAM" message pops up.

       

      I'm running PS CS6ext. 64bit on a WIN7prof./64bit system.

      RAM-usage set to 80% (=5694MB), about 300GB scratch on disk available.

       

      It's possible to have a previev with windows-explorer.

       

      Any idea what to do to open the files in PS?

       

      Thanks and regards!

       

      Felix

        • 1. Re: Problems opening a TIF with 14.828x18.446px (26,9MB)
          Level 7

          Are you running Photoshop 32 bit (which might run out of memory on that image) or 64 bit (which should open it).

          • 2. Re: Problems opening a TIF with 14.828x18.446px (26,9MB)
            Felix Fabian Level 1

            It's the 64bit version (13.1.2 x64).

            • 3. Re: Problems opening a TIF with 14.828x18.446px (26,9MB)
              Level 7

              Alright, then it should be opening.

               

              If you can send the file to ccox at adobe dot com (email, dropbox, etc.), I'll take a look at it after the holidays.

              • 4. Re: Problems opening a TIF with 14.828x18.446px (26,9MB)
                Level 7

                There are 2 issues here that combine to cause them not to open: the way the files were written, and how much memory Photoshop will allocate for decompressing a single image tile.

                 

                Image Width: 14101 Image Length: 18206

                  Resolution: 400, 400

                  Bits/Sample: 8

                  Compression Scheme: PackBits encoding

                  Samples/Pixel: 3

                  Rows/Strip: 18206

                  Number of Strips: 1

                 

                The images are written as one huge image tile/strip that decompresses to something around a Gig per tile.

                Decompressing that quickly is going to require allocating a buffer over a Gigabyte to hold the data.  Photoshop sets some limits on how large a tile buffer it will allocate so that you don't wait hours for the OS and Photoshop to free up the required space. Yes, we really had user documents that were spinning for an hour or more trying to allocate the buffer space to decompress them, even on a 64 bit system with quite a bit of RAM - hence the limits.  Your documents, written as a single huge tile, exceed the limits that Photoshop will allocate for a single tile.

                 

                The TIFF spec recommends that documents be saved in smaller tiles (though one line per tile is excessive).  Even moving to a few hundred Meg per tile would allow Photoshop to decompress the image data successfully.  Either you should choose different TIFF output options when scanning, or communicate to the makers of the scanner that they should read the TIFF specification and talk to Adobe about improving their TIFF implementation (which would send them back to me).

                 

                Also, the images are also written using PackBits (a run length encoding scheme) that is not a great compressor.  Using LZW or Flate would have decreased the size of the files considerably (half the size, or better).

                 

                For the time being, you can use some of the libTiff command line tools to unpack and repack these files to work better with Photoshop and other applications.