IMAQ ImageBorderOperation does not work

[rozo]

Hi everyone!

I have the following problem:
I obtained strange results in pixels close to the border after processing an image with IMAQ Convolute, then I added IMAQ ImageBorderOperation to have control on the border, but it did not change anything - all functions (Copy, Mirror, Clear) gives the same result!
Can someone tell me what is going on and how to solve it?
The Vi that I used to test the border is in the attachment.

Marcin

[mfitzsimons]

I tried everything and it doesn't seem to work.  I made some changes including adding set boarder size but made no difference

Matt

[mfitzsimons]

Here is a way to add a border.

Matt

[Andrey_Dmitriev]

Hi, rozo,

Hmm... IMAQ ImageBorderOperation seems to be OK. At least for 8 bit images.
I wrote small utility which able to visualize border and copy it to "normal" image (by access directly to the pixels),
and all looks very good.



But whats wrong with IMAQ Convolute? I has checked, and it works too. IMAQ ImageBorderOperation makes no sense for IMAQ Convolution, because IMAQ convolution perform mirroring of Border internally. (You can inspect source image after convolution - you will see, that border mirrored automatically). This is a reason why you cannot see any changes - if you will clear border before Convolute, then it will be added automatically inside of this function.

Can you attach screenshot - what's wrong with you "strange results"?

Andrey.

PS
Complete source in attachment. Code is "quick and dirty", its just for test, so may crashed in some cases...

[rozo]

Thanks for help!
Now I understand how it works.
It's just very annoying that the fact, that Convolute always mirrors image regardless of what kind of border operation one makes before, is not written in IMAQ help!

Marcin

[heywanna09]

Hi!

Is there any way to operate border copy in 16bit image? This method only works for U8 bit

Thanks in advance

[Andrey_Dmitriev]

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@heywanna09 wrote:

Is there any way to operate border copy in 16bit image? This method only works for U8 bit

---

In the given C code you should change type of the image from 1 byte unsigned char to 2 byte short (unsigned or signed - doesn't matter) - then it should work for 16 bit images as well.

[usrfrnly]

so... sorry but it has been like 15 years since this discussion began and they still haven't updated the IMAQ Convolute documentation to reflect the intrinsic border operation. I have no idea how else to bring attention to that other than this ridiculous reply. 

Bad NI!