

Geometric Statistics Problem ray from Singapore [5 posts] 
8 years

Hi Steven and Prof Mason,
Thanks for ur help in my last post about marker perimeter.
I have problem with geometric statistics in analysis module. May i know wut's the difference between top_left_X and left_top_X point? Sometimes both point give same value and sometimes they are not. It seems like there are 16 points for an image. When i point my mouse arrow to the point to verify the point location, the geometric statistics module could not give me the same value as the mouse pointer especially when image is distorted. I wonder why.
Actually i need those data for my analysis in my image processing project. Here i enclose my image and roborealms execution. I have problem in right top and bottom points where geometric statistics could not give me the same value when i verify it.
Is there other way to get the image points data? Pls advice. Thanks in advance.
From,
ray
program.robo



Anonymous 
8 years

Ray,
The difference between the top_left_x and the left_top_x is the bias of the point. For example, if you have a straight vertical line on the left which point is the left most? Probably all are but we then use left_top and left_bottom to indicate the leftmost lowest and leftmost highest points that would define that vertical line. Same with top (think of a horizontal line).
I assume you are trying to identify the square and get the coordinates of the square? If so you might try using the 4 Northwest, northeast, southwest and southeast points which should give you the four corners of the square. OR you can try the Replace_Blob module and select the MER or MEP to get the resulting variable array MER_COORINATES or MEP_COORINATES which will also have those corner points.
If not what are the desired points?
Thanks for the image!
Hope this helps,
STeven.



ray from Singapore [5 posts] 
8 years

Thanks for ur clarification about the point in geometric statistic.
The method u mention, it is really works and tat's the result i want. Thanks a lot!
U are the man!
Ray.

