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In my application I have black/white schematics with a title block in the lower right corner. The title block has several boxes (rectangles) and I need to find the coordinates of the corners of each rectangle. Note that in my application NO noise is present, and all edges are perfectly straight (0 and 90 degrees). What technique should I use to find the pixel locations of each box corner? Because of the simplicity of these images, I was hoping to avoid transformations like Hough

Here's a sample:

sample

Roger Rowland
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user3008597
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  • You can use the line segment detector to detect the lines and then check where they intersect: http://demo.ipol.im/demo/gjmr_line_segment_detector/ – GilLevi Nov 19 '13 at 12:47
  • Maybe a [corner detection](http://en.wikipedia.org/wiki/Corner_detection) like Harris, would be a good choice? – Roger Rowland Nov 19 '13 at 15:13
  • How about simple template matching with a 'cross'? – Mathai Nov 19 '13 at 17:09

1 Answers1

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IF the initial picture is clear and has clear edges and the lines have with 1px I'd use a 3x3 filter

|0 1 0|
|1 1 1|
|0 1 0|

Every 5 in the filtered picture is an intersection. Every 2 is an inner edge point inside the black

Marcel Blanck
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