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GregE
April 12, 2015, 05:29:26
My application runs the grabber live at a low resolution and then switches to to maximum resolution when the user requests a still image. The user can define an ROI by drawing a rectangle on the live low resolution image. When a still image is requested, I calculate the high resolution ROI based upon the low resolution ROI.

But I found that the left positioning of the still image was not correct, that is, the high res still image did not match the low res image with ROI applied.

I discovered that the issue was that below a certain resolution, the image isn't scaled, it's cutoff. It has 9 video formats. The top 3 show one area, the bottom 6 are cutoff (and scaled). You can see this running the DemoApp and looking at the left edge of the image under different video formats.

Is this correct operation? If it is, are there specs on what the scaling actually is between the different video formats so I can include the offset differential between my live view and snapped still image resolutions in my ROI calculations?

Stefan Geissler
April 14, 2015, 10:38:07
Hello

The ROI done in IC Capture by drawing the rectangle will be lost, as soon as you change the video format, that is resolution.

Stefan Geissler
April 14, 2015, 10:38:07
Hello

The ROI done in IC Capture by drawing the rectangle will be lost, as soon as you change the video format, that is resolution.

GregE
April 14, 2015, 20:25:38
Sorry, Stefan, I didn't detail that when I switch to the higher resolution, I set the ROI for the higher resolution as well. For example, if the X coordinate when running in 1600 width resolution is 100, I calculate the X coordinate when running in 4128 resolution as 258, since the ratio is 2:58:1 (4128 / 1600) between the 4128 and 1600 resolution.

The liveview does gives me a sub-segment of the image but since the higher resolution has a wider field of view then the lower, the calculated X a large number of pixels to the left of the intended area.

Like I mentioned before, you can see the difference in the DemoApp without any ROI. Run it at 1600 x 1200 resolution and note what you see along the left edge of the image, then run it at 4128 x 3096 and you'll see that it goes further out. I would expect the view field to be the same among all the formats only scaled down.

Stefan Geissler
April 16, 2015, 17:26:24
Hello Greg

I would have expected the same as you, but it seems the sensor manufacturer has a different opinion about this. Therefore, I am helpless here.

Stefan Geissler
April 16, 2015, 17:26:25
Hello Greg

I would have expected the same as you, but it seems the sensor manufacturer has a different opinion about this. Therefore, I am helpless here.