Line ROI with Float Values

[saranmahadev]

I am generating line ROI with a distance dynamically and the Line ROIs should be integer but when dynamically building the ROIs the values are changing drastically and I need a way around where I need my line rois in such precision. What can I do?

[raphschru]

Hi,

IMAQ ROI type definitions all use integer coordinates, and IMAQ functions only take integer ROIs as input.

What does "the values are changing drastically" mean, and what does that have to do with precision ?

If you need precision when computing the line coordinates, you can temporarily work on a SGL line, then convert to a an I32 line to give it as input to IMAQ functions.

If you really need the IMAQ functions to work with precise ROIs, you will need to upscale your image using "IMAQ Extract Tetragon". You can give an interpolation type (e.g. bilinear) and specify a destination resolution bigger than the original tetragon, which will cause an upscaling of the image. If you upscale by e.g. a factor of 10, an integer value of 1 in your ROI will effectively represent a 10th of a pixel in the original image. Using this method, your are limited by how much memory the upscaled image takes. You may want to extract only a small portion of the original image in order to limit the size of the upscaled image.

Regards,

Raphaël.