how to detect the region of scales
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I am detecting the position of a needle and scale markers in an analog gauge like the below. First, I transformed the gauge image into the rectangular image by polar coordinates. In the rectangular image, how can I detect the scale region marked by yellow color? Thank you.
(Analog gauge)
(Rectangular image)
(Target image)
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Image Analyst
2016-6-26
编辑:Image Analyst
2016-6-26
I don't see how you got the middle image. Somehow you transformed a circular hygrometer gauge with a scale of 0-100 into a rectangular thermometer gauge with range -30 to +50. I don't know how to do that. But anyway, once you've done that, you can just get the tick marks by looking at the scale, which should be in a fixed location. So
scaleImage = rectangleImage(row1:row2, col1:col2);
Once you've done one transform, you'll know what row1, row2, col1, and col2 are, of course.
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Image Analyst
2016-6-27
Then just find the center of the gauge and crop the image. Then scale it to a known size, like 1024x1024. Then do the spatial transform and the scale will be in the same place, guaranteed.
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