digital zooming upto 4X in steps of 1X

[SriSwathi]

Hi all,

I am trying to implement digital zoom algorithm using any interpolation technique up to 4X in steps of 1X for an image size of 640X480 image. I need to zoom only specific region of interest of entire image. Kindly let me know how this can be acheived using NI vision development module.

With best regards,

Sri

[muks]

How do you select the roi? manually? or from some other processing like pattern matching? have you tried the property node zoom for the image?

[muks]

Please try this

[Klemen]

Hello,

how about something like this (please see the attachment, saved for LV2010).

Select the ROI (currently manual ROI selection) on the original image and "Zoom"  to extract the selected subimage and resample to original size. You can repeat the process, as the original image gets updated with the currently zoomed portion of the image.

The interpolation is Labview default (zero or bilinear).

Best regards,

K

[SriSwathi]

Hi,

There is change in my application.

I need to zoom up to 4X factor in steps of 1X  for the image from centre and not any roi (region of interest based). So please let me know how this can be done.

with regards,

sri

[muks]

If you dont select the ROI then i think it will default to your image centre

[Klemen]

---

@SriSwathi wrote:

Hi,

There is change in my application.

I need to zoom up to 4X factor in steps of 1X  for the image from centre and not any roi (region of interest based). So please let me know how this can be done.

with regards,

sri

---

I don't understand - was the attached application helpful or you wanted something else?

If it was, then just create a ROI based on the image center with the desired offset. Find the center of the image, and get the top-left coordinates by subtraction and bottom-right with addition with respect to the image center. Then create the ROI from the coordinates using rectangle to ROI. Interpolate with the created ROI, repeat...

Best regards,

K

[SriSwathi]

Hi,

I actually wanted an real time zoom in function, wherein i have to zoom from centre of the image/frame. I could not understand the how to zooming  in steps of 1X up to 4X. Please help me out i have tried Imaq resample etc.

with best regards,

sri

[muks]

Resample is not Zoom. Did you try the programs suggested above?

[Klemen]

Hello,

you cannot zoom from the center of the image as in camera, since the camera uses so-called optical zoom. Here, we are talking about digital zoom (the optical parameters don't change and the image quality is reduced by interpolation). In this case, you need to specify the portion of the image to enlarge and resample.

Have you seen the example in one of te previous posts? Just modify the ROI, so that its center coincides with the image center.

Best regards,

K