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refuses to open large PNGs

Posted: Mon Jan 22, 2007 3:16 pm
by JohnFredC
This is a preliminary report because I cannot find a clear pattern that repeats.

Frequently XnView refuses to open large PNGs.

Behavior is:
  • - Open Browser
    - Show Preview-Preview
    - Navigate to folder containing a "new" large PNG
    - Wait for XnView to build the thumbnail
    - Navigate (in the file list) to the thumbnail
    - XnView blinks, preview does not display
    - Attempt to open or full screen the PNG
    - XnView blinks and does not open or view the PNG
Sometimes, after encountering the above behavior...
  • - Close XnView
    - Reopen XnView
    - Repeat above steps
    - PNG previews and opens normally

At first I thought the bug was related to PNG file size and had (by trial and error) narrowed the problem down to PNGS > 107Mb. However, today XnView refused (at first) to open a 26Mb PNG that is 15k x 5k, so perhaps it has to do with the PNGs' dimensions, instead.

My system: XP Pro, 1 Gb RAM, 3 Gb swap

I understand it may be a memory request/managment issue, but XnView should at least tell me why it refuses to open a file. Something like: "Unable to open file. Memory needed ??Mb, available ??Mb."

Just an aside: Picasa has no problem opening the problematic images.

V 1.90 RC2

Re: RC2 (and prior?) refuses to open large PNGs

Posted: Mon Jan 22, 2007 4:40 pm
by xnview
JohnFredC wrote: I understand it may be a memory request/managment issue, but XnView should at least tell me why it refuses to open a file. Something like: "Unable to open file. Memory needed ??Mb, available ??Mb."

Just an aside: Picasa has no problem opening the problematic images.
Yes, with the preview i don't show error message, it's normal.
But it's strange that you can't open it. Even by opening xnview, close the browser, and open the png in view mode?

Re: RC2 (and prior?) refuses to open large PNGs

Posted: Mon Jan 22, 2007 6:28 pm
by JohnFredC
xnview wrote:Even by opening xnview, close the browser, and open the png in view mode?
Just now the problem has occurred.

- Opened XnView
- Displayed the browser
- In the browser, selected the thumb for a 178Mb png.
- The preview appeared properly!
- Selected the "open" button on the toolbar
- XnView blinked but nothing else.

- With the browser still open...
- Selected File->Open, navigated to the same file and attempted to open it.
- Eventually XnView displayed an "Out of Memory" alert. (Ahhh!)

- Closed the browser
- Selected File->Open, navigated to the same file and attempted to open it.
- It opened!!! (another Ahhh!!!)

This behavior is repeatable!

(I never use XnView without the browser, so hadn't thought about this work-around. Silly me!)

Re: RC2 (and prior?) refuses to open large PNGs

Posted: Mon Jan 22, 2007 7:40 pm
by xnview
JohnFredC wrote:
xnview wrote:Even by opening xnview, close the browser, and open the png in view mode?
Just now the problem has occurred.
Do you reproduce it with 1.82.4, prior is perhaps for that :-)?

Posted: Mon Jan 22, 2007 9:37 pm
by JohnFredC
I was unable to test 1.82.4, but do have a copy of 1.82.2 on my old laptop.

The 1.82.2 environment is 384Mb RAM. The 1.82.2 browser will preview the PNG I am testing with (179Mb), but won't open it.

After closing the 1.82.2 browser, File->Open displays the PNG. (I think that is amazing, considering the memory constraints. Took about 30 minutes to open, though.)

To conclude: I can confirm exactly the same behavior with the very same file in version 1.82.2.

Another point: using RC2 on the 1 Gb machine, the Compare function works correctly from the browser on 2(!) 179Mb files, even when the browser itself refuses to "open" either one of them.

Hope this helps.