IMAQ Zoom to fit option changes the image details

[SweathaK]

Hi,

We see that using the zoom to fit option in LabVIEW IMAQ Display adds some stripes to the image which we do not see in the actual image.

I need to know why this behavior is seen and how to avoid this.

Thanks,

Sweatha

[altenbach]

What you see are Moiré patterns due to a non-integer relationship between image pixels and monitor pixels.

[SweathaK]

We have 2 systems - one runs LV 8.2 on windows XP and other runs LV 2020 on windows 10.

In LV 8.2 there is no issues seen and zoom in/out is done by factor of 2X (1X,2X,4X,8X,..). In all the zoom levels, the pattern is looking the same

But in LV2020, it scales in 1+ (1X,2X,3X,4X,..). This pattern issue is seen at certain zoom levels like 0.17X and Zoom-to-fit.

Is there a way to change the zoom factor in LV2020 to zoom the same levels as old LV?

[Quiztus2]

I dont know 8.1 but I would check if your imaq displays are the same size in both versions. Maybe one is one pixel wider.

[RamonG · Accepted solution]

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@SweathaK wrote:

But in LV2020, it scales in 1+ (1X,2X,3X,4X,..). This pattern issue is seen at certain zoom levels like 0.17X and Zoom-to-fit.

Is there a way to change the zoom factor in LV2020 to zoom the same levels as old LV?

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It doesn't look like you can. You could add a Mouse Up/Down event case in your event structure, read out the ZoomInteger property and adjust it accordingly but it will be quite convoluted.

I would add a few buttons and use the event structure to set the zoom to 1x, 1/2x, 1/4x etc.

As for the zoom to fit function; you could change the Image Area Size property to be 1/4 of the original image size so that zoom to fit will be the same as 1/4 zoom.

In this case: