3.07 Open file anomalies

[serbach]

Dear Group,

I've written about this issue before (October). I've just recently gotten interested again in using paint.net, so I downloaded the latest version to give it a try. Here's the situation:

1) My system is an Intel Core Duo E6600 with 4 GB of RAM running Windows XP x64 Professional Service Pack 2.

2) The image I wanted to load is a 13 KB Windows bitmap, 66 x 66 pixels.

3) The folder in which the file is located contains quite a number of other graphics: 294 JPEGs, GIFs, TIFFs, BMPs, ICOs, and PNGs. The smallest is a 1 KB GIF, the largest is a 600+ MB TIFF.

4) I ran SysInternals Process Monitor to watch what Paint.net does. As soon as the File | Open dialog box appears, Paint.net begins performing thousands of ReadFile operations on a large TIFF (289 MB) in that folder. I click on the file I want to open while all of these ReadFile operations are being performed, and Paint.net "freezes" until that big file has been read as far as Paint.net wants to take it. In Process Monitor I see that the file finally has a CloseFile operation performed on it after the entire file has been read...then the little bitmap I want opens and I can edit it.

5) That large TIFF is LZW compressed. Its size in RAM is in the neighborhood of 7 GB. In Windows Task Manager, I can see that over 3 GB have been read (in the I/O Read Bytes column) while I've waited for my 13 KB bitmap to open.

6) While I was composing this message I did a File | Open again in Paint.net. I didn't select a file I just let the Open dialog box sit there. Process Monitor showed that that same TIFF file was being read. Task Manager's I/O Read Bytes began to shoot through the stratosphere again.

7) Since I continued to type this message I let the File | Open dialog sit there. Process Monitor showed that once Paint.net had finished with the first large TIFF, it started on another, then another... 993,428 MB of files in total before I finally opened another small graphic. Windows Task Manager now shows me that Paint.net has read 7.6 GB from disk. While all that disk activity is taking place, Task Manager also shows me that Paint.net is consuming between 35% and 50% of my dual core CPU.

So what's going on here? Why all the reading of large TIFF files (they're all TIFFs) while I'm deciding which file to open and work on? Why, when I do chose a file, does Paint.net continue to read the large TIFF it's munching away at...and only then opening the file I want?

Regards,

Steve Erbach

Neenah, WI

http://TheTownCrank.blogspot.com

[/i]

[Rick Brewster]

What you're describing is simply the behavior of the common "Open" dialog that Windows provides when it is set to the Thumbnail view. Try this in any other application and you will see the exact same behavior.

[serbach]

Rick,

Just as you say, when I switch my Windows Explorer view of that graphic-heavy folder to thumbnails, Explorer takes 50% of my CPU and reads gigabytes of data.

It appears that the default view of any folder I go to in the File | Open dialog box in Paint.net is thumbnails. I don't suppose there's a way to change that, is there?

Thank you for the quick response!

Regards,

Steve Erbach

Neenah, WI

http://TheTownCrank.blogspot.com

[jal]

It appears that the default view of any folder I go to in the File | Open dialog box in Paint.net is thumbnails. I don't suppose there's a way to change that, is there?

Like Rick said, it's the standard Windows open dialog. That means that you can select the view, by pressing the 'view' button above the file area. Choose e.g. 'Details', and every folder you browse has details instead of thumbnail view.

JAL

[serbach]

Like Rick said, it's the standard Windows open dialog. That means that you can select the view, by pressing the 'view' button above the file area. Choose e.g. 'Details', and every folder you browse has details instead of thumbnail view.

Yes, I understand that. I was asking how to change the DEFAULT file view in Paint.net. I can change the default in Windows Explorer or, say, Microsoft Access. In Windows Explorer the Details view doesn't cause the entire folder's contents to be read. Can I do that in Paint.net? Every time I open an image in the folder in question, 2.5 GB of I/O is read, 50% of the CPU cycles are eaten up, Paint.net "freezes", it shows up as "Not responding" in the Windows Task Manager, and, finally, after 35 seconds, my image opens and I have full control again.

I can still use Paint.net under these circumstances but I will be careful only to open files in folders that have very few images so that the Thumbnail view will not cause Paint.net to freeze for very long. It would just be nice if I could set the Open dialog box to default to Details view to avoid all the file and CPU activity.

Sincerely,

Steve Erbach

Neenah, WI

http://TheTownCrank.blogspot.com

[jal]

Yes, I understand that. I was asking how to change the DEFAULT file view in Paint.net. I can change the default in Windows Explorer or, say, Microsoft Access.

Well, various programs (even MS ones) act differently, so I guess in theory it may be possible for paint.net to remember the default (I'm no .NET programmer though, so I'm not entirely sure).

In Windows Explorer the Details view doesn't cause the entire folder's contents to be read.

The Details view never does, only the thumbnail view does. But even then, once Windows has processed such a directory, it doesn't proces the files again, unless they have been changed, or the thumbs.db file is removed.

Can I do that in Paint.net? Every time I open an image in the folder in question, 2.5 GB of I/O is read, 50% of the CPU cycles are eaten up, Paint.net "freezes", it shows up as "Not responding" in the Windows Task Manager, and, finally, after 35 seconds, my image opens and I have full control again.

That is extremely weird. As I said, it should happen only once. What happens if you navigate to that directory with the Explorer in thumbnail view?

I can still use Paint.net under these circumstances but I will be careful only to open files in folders that have very few images so that the Thumbnail view will not cause Paint.net to freeze for very long.

You can navigate using another view (e.g. Detail or List), this should not cause the behaviour you described.

It would just be nice if I could set the Open dialog box to default to Details view to avoid all the file and CPU activity.

I agree, it would be a nice feature if PDN remembered both the directory and the view mode it was left in, and/or had a setting to specify it.

JAL

[Rick Brewster]

This has been covered many times before but I'll summarize here as well.

In Windows XP, we do not have an official way to set and then remember the view type that is used. We do have an unofficial way -- a hack, really -- to set the view type used (but not to retrieve it afterwards). We found that most people, including myself, wanted to use the thumbnail view from Paint.NET, but that Windows was always defaulting to something like Details view. So, we force the dialog to use Thumbnail view. This works great for most (in fact, almost all) situations, but like you've detailed there are a few cases where this does not work satisfactorally.

In Windows Vista, we use the new programming API's for the open/save dialogs. These do remember the view types used and are smarter about applying the thumbnail view when navigating to a folder with images. The performance is also much better, as the thumbnail work is done either in background threads or out-of-process.

[serbach]

This has been covered many times before but I'll summarize here as well.

Rick, I apologize for bringing it up again. Didn't quite know what to search for in the archives. In my job I work with enormous graphics in .NET. I never use thumbnail view or "preview" for anything.

In Windows Vista, we use the new programming API's for the open/save dialogs. These do remember the view types used and are smarter about applying the thumbnail view when navigating to a folder with images. The performance is also much better, as the thumbnail work is done either in background threads or out-of-process.

Thank you for the detailed explanation. I will adapt my use of Paint.net to avoid the delays in opening files. In this case I don't need to see all of those other (huge) files. I can, with a bit more thought, set up subdirectories with fewer graphics in them and simply realize that I need to wait a bit if I venture into any folder with loads of large images.

Sincerely,

Steve Erbach

Neenah, WI