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slow image loading

rtalianortaliano
in Image-Pro General Discussions
I am experiencing very slow image loading times for image pro premier.  The computer is a 4-c hyperthreaded xenon,  32 GB RAM with SSD drive on which program resides. Image files are on internal PCE standard drive. It takes minutes to open a 1 GB image.  I am thinking I have something configured wrong?  Any thoughts on settings that should be checked/changed?

Best Answer

  • CraigWCraigW
    Answer ✓
    I've tested the two image files you sent, and here is what is going on:

    One of the files, "Malaria MEOH fixed_Crop_median5x5x2.tif" is a 268MB uncompressed TIFF format image which opens and is displayed quickly.  I expect that you also see this behavior.

    The other file, "Malaria fixed crop scan.svs", is an Aperio SVS format 24-bit RGB image of 142,385 by 39,533 pixels which occupies 937MB on disk, but takes up 15.727GB when uncompressed.  Under the hood, this image file is a BigTIFF format (64-bit offsets) multi-resolution image.  Sub-sampled resolutions are available at powers of two from 1/2 to 1/1024.  The compression used is JPG2000.

    Your basic problem here is that you have a lot of physical memory, which Premier 9.1.4 inadvisably decides is enough to open the entire 15.7GB frame all at once as an ordinary image.  This would take a while for 15GB in any case, but the problem is made much worse by the JPG2000 compression, which is very slow to decompress.

    Under the soon to be available Premier 9.2, all multi-resolution SVS images will open into a Large-Image workspace which does not attempt to load the entire image all at once and takes advantage of the sub-sampled resolutions available in the file.  You can make this happen in Premier 9.1.4 by decreasing the Managed Memory Limit, so that the "Total managed memory" is less than 125% of the decompressed frame size.  For this image, a Managed Memory Limit of 60% should result in the example SVS image opening into a Large Image workspace.

    If you decrease your Managed Memory Limit to 50%, then SVS images with uncompressed frames of about 11GB or more will open in a Large Image workspace. With JPG2000 compression, these images smaller than this limit will still be slow to open but the wait should be tolerable.

    Under the coming Premier 9.2, all multi-resolution SVS images, even small ones, will open in a Large Image workspace.  A 9.2.1 patch will follow shortly the release of 9.2, and after patching to 9.2.1, with Managed Memory Limit set to the default of 60%, your SVS images that are smaller than about 6GB uncompressed will open as normal images.  Display will be faster compared to 9.1.4 for these relatively smaller images, however, because in 9.2.1 normal image display takes advantage of available sub-resolutions.  Naturally, if you try to do some operation on the image that requires every pixel to be visited, the entire frame will need to be uncompressed and this will sill be slow for these multi-GB JPG2000 compressed frames.



Answers

  • CraigWCraigW
    Is your 1GB image a single frame or many smaller frames?  What is the image format (e.g. TIFF, JPG, etc.). During the open, do you see a progress bar on the status line?  If so, what does it say is the operation being performed?  Are you showing a histogram of the image?

    Open the Resource Monitor Panel (the little multi-colored button in the group at the right end of the status line).  In the "Resource Details" section, what do you see for the "Total Managed Memory"?  After the image is fully opened, what do you see for the "Committed Memory" and "Potential Memory" values?

    If you copy your image file to your SSD drive, and then open it from there, does it open much faster?
  • rtalianortaliano
    Craig,  the image type does not seem to matter. I am using .svs and TIFF's and both are effected. When the image is opening the only thing I see is the spinning icon and  "Not Responding" at the top. It will stay that way until the image finally pops open. Total managed memory is 21.625 GB (I bumped the managed memory limit up to 76% but to no avail). Same thing happens when file is opened from the SSD and time to open seems to be about the same as well. Managed memory usage goes to 73% when image is open...obviously much larger than the size of the file as listed in file folder. Potential memory when image is open is 15.728 GB.
  • rtalianortaliano
    Thanks Craig. At first seems counterintuitive but when explained makes perfect sense.
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