BUG: Background Image

[Wiebe@CARYA]

Hi,


Here's a annoying bug. I finally found a way to reproduce it, I hope it's reproducible on other pc's. If anybody has a solution (besides not changing the background), I'd very much like to here it.



In LabVIEW 8.2:


Create a new VI, with a property node, and link it to the pane (Link To>Pane).
Select "Background Image".
From "Graphics & Sound>Picture Functions", select "Draw Flattened Pixmap"
Create a Picture control indicator.
Right Click the scroll bar, and select Properties.
Select the "Clouds" background.
Save Close and reopen the vi.
Run the vi. A nice picture of the background appears.
Change the background to "Wood - Oak".
Run the vi. Now the colors are inverted, like a color negative!
Change back to "Clouds", the colors are still inverted!


For some reason, I created an even worse situation, but I don't know how. When I start a vi, I get an inverted background image at first run, without changing my background! I Need this background to draw a semi transparent png file manually (with alpha blending), so this bug is a real show stopper. Copying the code to a new vi results in the same problem...


Regards,


Wiebe.

[Wiebe@CARYA]

"Wiebe@CARYA" <wiNOebe.walsSPtra@carAMya.nl> wrote in message news:461637ad$1@PYROS.natinst.com...
Hi,


Here's a annoying bug. I finally found a way to reproduce it, I hope it's reproducible on other pc's. If anybody has a solution (besides not changing the background), I'd very much like to here it.



In LabVIEW 8.2:


Create a new VI, with a property node, and link it to the pane (Link To>Pane).
Select "Background Image".
From "Graphics & Sound>Picture Functions", select "Draw Flattened Pixmap"
Create a Picture control indicator.
Right Click the scroll bar, and select Properties.
Select the "Clouds" background.
Save Close and reopen the vi.
Run the vi. A nice picture of the background appears.
Change the background to "Wood - Oak".
Run the vi. Now the colors are inverted, like a color negative!
Change back to "Clouds", the colors are still inverted!


For some reason, I created an even worse situation, but I don't know how. When I start a vi, I get an inverted background image at first run, without changing my background! I Need this background to draw a semi transparent png file manually (with alpha blending), so this bug is a real show stopper. Copying the code to a new vi results in the same problem...



Well, at least I found a way to "fix" the last problem. I changed 1 pixel in the right bottom of the bmp, saved it, change the background to it, closed the vi, and then the problem didn't occure... Changing back to the old picture did cause the problem again.


Regards,


Wiebe.


Regards,


Wiebe.

[smercurio_fc]

Wiebe, I'm sorry to nitpick, and perhaps it's just me. If that's the case I apologize for my annoyance. However, could you turn off the "copy original message before my response" option? This thread is a perfect example where it makes it really difficult to read the messages. In your response to yourself, you have to go back to the original message to find out where it ends so we can find out where your response begins. The original messages are there for everyone to see. There's no need to replicate them in a response.

[Wiebe@CARYA]

Normally it's considered good practice to keep the original message, so you can tell what part of the message someone is responding to. You mean to tell it's not, or just no to do it when answering myself?


I'm reading this forum in Outlook Express, and it's perfectly clear. I do have some problems, some posts turn up in html-ish form, with all the enters replaced by &nabs;


Regards,


Wiebe.

[smercurio_fc]

Ah, you're using Outlook Express. That explains it. If you use the web interface by going to http://forums.ni.com/ni/board/message?board.id=170&message.id=240199 you'll see what I mean.

You're perfectly free to do what you want - I can certainly live with it. However, as you can see from the posts on this forum, the general trend here is to not include the original message. Don't know if that violates some unwritten convention or not, or whether the convention you mention is a carry-over from the old USENET days, but there you have it. It is certainly not my intention to create a big stink over this, and I'm not ordering you to do it my way. Please do what you see as best for your application.

As an aside, I've never seen the behavior you mentioned with Outlook Express with the Enters being replaced. But then, the Outlook Express hasn't really been updated in a while. Maybe you'll have better luck with an alternate newsreader? I've used xnews. It has a clumsy interface, and looks UNIX-ish, but may be worth a shot for you. I've heard good things about Forte's Agent as well.

[zou]

Does this bug happen when you programmatically change the background?

George Zou

http://gtoolbox.yeah.net

[NIJanell]

Hello Wiebe,

I am able to reproduce this issue - to a point.  If I follow your directions and change the background and then run the VI, I do get the color negative in my picture indicator.  However, if I choose not to save the changes, reopen the original VI and never change the background, the color negative never appears.  Is this the same behavior you are seeing?

Thanks,

Janell R | applications engineer

[Wiebe@CARYA]

From what I can tell, the bug happens when the background is changed by the user, in a saved VI only.


When I programmatically change the background, sometimes the problem resolves, until you save the VI, reopen it, and change the background again...


I did a lot of testing, trying to find a way to get the image after a change of background. Finally, I noticed that when I changed one pixel in my png, it didn't happen (I could at least change the background once).


I also noticed that the background pixmap I'm getting, has one color filled with a value. The picture is 24 or 32 bits, so it shouldn't have a color table! In the correct pixmap, when I delete this color, I get the same abnomally (although I get different colors, sometimes the sky gets purple or green).


When I finally fiddled around so I got a good background, I noticed a black dot in the top left corner. Strangelly, when I get a subimage from the pixmap (e.g. 40,40,100,100), there is still a black dot in the top left corner!


I got my workaround. I load the picture from file, and use that (I use the resulting pixmap as a constant) instead of the background.


Regards,


Wiebe.