# Corners of an image

**URL:** <https://discourse.julialang.org/t/corners-of-an-image/13465>\
**Category:** General Usage\
**Created:** [August 14, 2018, 9:06pm UTC](https://discourse.julialang.org/t/corners-of-an-image/13465 "2018-08-14T21:06:17Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![microlifecc](https://avatars.discourse-cdn.com/v4/letter/m/ed655f/32.png) [@microlifecc](https://discourse.julialang.org/u/microlifecc)\
**Post date:** [August 14, 2018, 9:06pm UTC](https://discourse.julialang.org/t/corners-of-an-image/13465/1 "2018-08-14T21:06:17Z")

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Hi Guys! I am writing some code for feature detection.

I was wondering if there is a way to find the corners of an image, for instance the actual image provided to us is not necessarily a rectangle(maybe a parallelogram or some random shapes with corners and edges).

Thanks!

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**Author:** ![yakir12](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/yakir12/32/297_2.png) [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Post date:** [August 14, 2018, 9:09pm UTC](https://discourse.julialang.org/t/corners-of-an-image/13465/2 "2018-08-14T21:09:08Z")

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I’m not sure I understand, the image is not in a rectangle matrix of pixels? Or are there pixels you consider not part of the image?

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**Author:** ![microlifecc](https://avatars.discourse-cdn.com/v4/letter/m/ed655f/32.png) [@microlifecc](https://discourse.julialang.org/u/microlifecc)\
**Post date:** [August 14, 2018, 9:10pm UTC](https://discourse.julialang.org/t/corners-of-an-image/13465/3 "2018-08-14T21:10:59Z")

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@yakir12 Thanks for the response!  
I mean the pixels are not arranged as a rectangle. Maybe arranged as a parallelogram. Thus still having 4 corners.

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**Author:** ![tomaklutfu](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tomaklutfu/32/2411_2.png) [@tomaklutfu](https://discourse.julialang.org/u/tomaklutfu)\
**Post date:** [August 15, 2018, 8:26am UTC](https://discourse.julialang.org/t/corners-of-an-image/13465/4 "2018-08-15T08:26:05Z")

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It would be useful if there is a reference/specification or standard of such images or layout of memory structure. For example, rectangle images can just be matrices, then how would one define a parallelogram as data structure?