LV7.1 upgrade: bad CDs?
I was getting ready to upgrade to LV7.1 from 7.0 but have gotten information from the Info LabVIEW Mailing List that some folks are having problems with the install. One person reported receiving a second LV7.1 package with a letter stating to destroy the first kit and to reinstall if I was already using the update. Can NI comment on this and how do we know whether to proceed with install and / or wait for second shipment? Sincerely, Don
Re: 2d cross-correlation (for image correlation): some questions
Hi Michael: Thanks for looking at this for me. The other issue is that when I use the IMAQ VISION cross-correlation fx (which allows me to do direct image correlations without having to do the fft steps), I get different answers than what I get with my LabVIEW routines. I believe that most of this just has to do with scaling but because I cannot see the 'c' code of any of the routines, I am not sure. I tend now to trust the IMAQ VISION routine more because when i correlate two identical U8-format images, I get a cross-correlation maximum of 256 (which I expect to be the maximum possible value for a U8 type image). Then when I correlate two non-identical images, or use subset images, I always get less than this for the maximum. My goal was to implement this procedure without IMAQ Vision since that is the only place I would need Vision for this code. I would appreciate it if you might be able to have one of your math gurus right at NI take a look at this. Any chance of this? thanks, Don
Re: Save front panel to bmp - not working anymore in LV7
I found two issues with my VI. I don't know why it ended up working for you as is, but I got it to work after the following mods. I placed a new invoke node (for 'Get Image') onto my diagram. It now seems to work. The old invoke node when I upgraded from 6.1 to 7 had a title of something like 'Old Get Image'. Originally, instead of replacing the invoke node, I just changed the method of the old invoke node to 'Get Image' while keeping the same invoke node (and also adjusting the code appropriately for the new graphic/picture fxs). Now, I deleted the old invoke node and replaced it with a new invoke node. I am thinking there was an issue because of this. Also, even though i was sure that I watched the code with execution hiliting on so as to make sure the dataflow was going into the 'write bmp (or png, jpg, etc) function,' I now see that it is not. The reason is is because I did not choose my cases to have 'case insensitive match.' If you look at my file choice handler, the file type is coming out as lower case while the cases are labeled in upper case strings. By choosing 'case insensitive match,' the dataflow is correct and now the VI works.
Re: i am gettign objheap.cpp error
I am also getting this identical objheap.cpp error at the same line number 592. I was editing my VI yesterday on a computer using winXP operating system. Today, I am trying to bring it up on win2K OS and it will not even open due to this error!! I would like to send the code to NI but it has a lot of subVIs and since I cannot open it, I cannot get the heirarachy. I suppose I could send the directory(s) to them. Any advice is appreciated. Sincerely, Don
Re: Using Numeric Integration.vi: Is this correct?
Hello Franz: I have contacted and left messages with the authors of the article that I saw the formula in but your argument makes sense. I am familiar with the FFT and correlation process and in fact we use the hanning window to reduce the artifacts of the discrete fourier transform just as you say. Thanks a lot for your help. I will post the final answer when they get back to me. I am glad I had someone else take a look at this. Now the next step i have to figure out is how to do this in 2d, that is in the spacial image domain. I want to work and calculate the formulation of the nonsymmetry coefficient in the 2d domain. I am going to start with the FFT of the image and the complex conjugate of the FFT of the image to get corrrelation function. At this point, I am a little confused on how to use numeric integration in labview in the 2d domain so need to study that some more. Sincerely, Don
Re: Using Numeric Integration.vi: Is this correct?
Per one of the authors: As for the nonsymmetry coefficient, this integral is just a measure of the mirror symmetry of fcc around taumax. It would be zero if perfectly symmetric. The integration should really be from 0 to +infinity, but as before, outside of some range of tau, both fcc(taumax-tau) and fcc(taumax+tau) (these are functional evaluations, and not multiplications) will both go to zero. So the integral may be appropriately truncated. So you were correct and I thank you for pointing this out. As explained, this makes perfect sense. Thanks again, Don
Re: Using Numeric Integration.vi: Is this correct?
This is an extremely good point and I need to contact the authors of this article who first used the Nonsymmetry coefficient and determine the correct usage. I guess the reason I assumed multiplication is because the value of fcc at (tau_max - tau) over the period of the integration can result in a lot of values that cannot be evaluated because tau_max - tau will be negative (egs. fcc(-10 usec)) and the correlation fx produced I believe starts at time = 0 and proceeds positively). What do you think? But I will contact them. Sincerely, Don
Re: source code for 2d cross-correlation fx?
thanks, i will take a look...The correlation fx uses the FFT so I suppose if starting from scratch with the FFT and knowing the algorithm for correlation, I can make the modifications as needed. Cross-correlation involves multiplying the FFT of one fx by the complex conjugate of the FFT of the second fx (I believe). Since LabVIEW and IMAQ have all these operations, I should be able to work with this. Sincerely, Don
Re: Windows Management behavior in LV7: Win2K vs. WinXP
I tried that workaround and it did not work unless I made the main panel a floating window rather than having default window behavior. But I think we are thinking in the same direction.
Windows Management behavior in LV7: Win2K vs. WinXP
I have noticed some strange behavior regarding windows management in LV7 in winXP that did not occur in win2K (identical code). My main front panel has 'default' windows behavior. I have a pop-up subVI with 'modal' windows behavior so that it will be on top when called. In win2K, works fine. In winXP, modal subVI shows up behind main front panel. When I change the behavior to 'floating' from 'default' for the main front panel, things work as they should in winXP. But I do not see why I had to change to 'floating' behavior for the main front panel. Any ideas here? FYI, I extensively used the winutils.llb labview windows management toolkit when developing the application (in LV6.1 days) to control windows ontopness and floating behavior for VI server-called VIs, but it does not play a role in this particular problem (I do not call any of the VIs from this toolkit until later in the application). Thanks, Don
File Permission Error (8) when trying to delete file
I am trying to programmatically delete (using the delete fx) a config(.ini) file that was originally created using the Open/Create/Replace fx. The file directory path is correct and the file is closed prior to the delete operation. I get a file permission error (8) when attempting the delete operation. I even tried adjusting the file access rights for full to see if that would make a difference but it did not. I am at this point not able to identify why I am getting this error, but I suspect it is something obvious. Your thoughts are appreciated. Thanks, Don
Re: File Permission Error (8) when trying to delete file
The code is a subsection to source code of over 100 mb llb for our ultrasonic scanner. I am trying to figure out a creative way to form a simple version of the problem but whenever I craft a basic VI utilizing the delete fx, the delete operation works just fine So as of yet I am not able to reproduce the problem in a simple VI. That is why I thought some folks could shed light or suggest some things to look for. As I indicated in the initial post, I thought the origin of the problem could only be three possibilities: 1) the file is of the wrong name and therefore not found (although would probably get file not found error) but in fact it is the correct file and path, 2) the file is still open (it is not, I close it right before the delete fx), or 3)somehow some permissions have been set that do not allow a delete operation.
Open/Create/Replace fx question
Is there any way (certain syntax needed) to get all files of specified types to display in files portion of dialog when specifying multiple file types (egs. *.png,*.bmp,*.jpg) for the pattern input in Open/Create/Replace fx? When one specifies just one type (eg. *.png) in the pattern input, all files of that type display in the files section of the dialog as expected.
Re: Displaying files of custom pattern types specifying multiple types
Yes, thanks this works and I should have read the help for the function more carefully.
Re: Open/Create/Replace fx question
I am answering my own question which is clearly addresed in the help for the Open/Create/Replace fx. The items must be separated by semicolons (not commas as I was doing).
Vision Builder 7.0(IMAQ) : Using fxs in subVIs with references to image control
When using IMAQ fxs (such as 'Write File') in subVIs, if one wanted to use references to an image control, what property or method would be used to feed into the image terminal in the imaq fx on the subVI? Is this possible? What did work: I was able to directly use the image control on the main feeding an image control on the subvi panel (which is then fed directly to imaq fx) What did not work: From a refnum control for the image on the main, I used (within the subVI) the value property fed to a 'Variant to Data' with type as image control, then feeding the output of this into imaq fx.
Displaying files of custom pattern types specifying multiple types
Using Open/Create/Replace file fx, one can specify custom patterns using the custom pattern input, and if only one type is specified, all files of that type that exist in that directory path show in the file section of the dialog. For example, if I use *.bmp as the custom pattern, all files of .bmp type display in the file section of the dialog that exist in the directory. However, if I specify multiple types for custom pattern, files of those types specified in the custom pattern do not show in the files section of the dialog. For example, if I specify *.bmp, *.jpg, *.png as the custom pattern, no files of these types display in the file section of the dialog. Why is this, and is there a workaround?
