Zoom factor property in picture indicators

[AkkiTriple5]

Hi everyone,

Does increasing image size (in pixels) using the zoom factor property note affect the clarity of the image. I was just yesterday acquainted with Raster and Vector Graphic Images and effect of image scaling on them.

I need to rescale images in my application without affecting clarity, and also being reasonably fast (image size 2592 * 1944 pixels (2 MB approx.)) like 3-4 seconds maximum. Is it possible to do that in labview. I am currently displaying images using simple picture indicators.

Is it worth giving a try? Any suggestions would be helpful. I am currently using labview 8.5 evaluation without any image processing toolbox.

[GerdW]

Hi Akki,

Is it worth giving a try? Any suggestions would be helpful.

Well, instead of creating a new thread, writing your text and waiting for an answer you could have easily wired up this property node you are talking about and test its behaviour. Did you?

The scaling algorithm used in the picture indicator is rather simple. And maybe it would also help when you define your expected "clarity of the image"… 😄

[AkkiTriple5]

Hi GerdW,

Actually I am on a strict deadline for an application, and resizing the images to container size for less scrolling was just an optional feature. Hence, I was looking for some quick information.

I had tried zoom factor property, and it did blur the image. However, at that point I was confused with Lossless compression and blurring. I have been asked by my mentor to only consider lossless compression while resizing. That, however requires some more looking around. If I get time to add this feature, one possible way would be to make a sub-VI (Converting jpg to png and resizing), since most of my source images would be in JPG format.

I do agree that I didn't follow the methodology for learning labview in the long run. Kindly do keep answering my posts. There are a lot to come once debugging begins!!

Regards

Akash Kumar Nigam

[GerdW]

Hi Akki,

I don't understand that relation between (non-)compressing file formats and resizing images for display in an indicator. Do you understand this?

(Converting JPG to PNG before resizing doesn't change anything: the image data for the resizing step will be exactly the same!)

[AkkiTriple5]

Yes, after some time I was also thinking the same.

Would ask my mentor and inform you if anything comes up.

[AkkiTriple5]

Hi,

I talked to my mentor regarding this. He showed me the earlier version of the application I am building (which was build by someone else on Labview, I cannot post it here). During resizing the larger images in that application to fit indicator size, there was some horrible mixing of colors, (there was purple and red tinges in some areas, which are not there in any image). My mentor said this was lossy compression.

I have not observed such effects in zoom factor property, however since I do not know the algorithm I am not that sure. I can use scilab resize function in labview if so required, it has also shown satisfactory performance.

Kindly suggest what could be the reason of the color mixing (I don't even have the source code), and can zoom property node create any such problems??

[GerdW]

Hi Akki,

what could be the reason of the color mixing

I guess it's the algorithm used in this old program. YOu need to examine that algorithm…

(I don't even have the source code),

Ask your mentor for it. If this tool was developed inhouse you should be able to get the code…

can zoom property node create any such problems??

Don't know. Maybe it also depends on your image data?

You neither show any example data nor do you show current and expected results…