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### Shape detection and Image Processing

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```Hi all,

I am looking to create an image by randomly generating a number of X and Y co-ordinates and then randomly joining a selection of these points with lines to create an abstract image. The arrangement of these lines will produce a variety of different closed shapes inside the image. I then need to be able to analyses these fundamental closed shapes (as well as the combinations of neighbouring shapes).

I am competent in matlab but new to image processing techniques and am looking for a way to identify these closed shapes so that I can calculate their internal angles, side length and area.

Essentially I want to randomly create abstract images which contain a number of triangles defined by both fundamental closed shapes as well as combinations of neighbouring shapes. There are constraints on the type of triangles appropriate (minimum angle, minimum side length and minimum area) so I need a technique to eliminate those displays which fail to meet these criteria.

Any direction or suggestions would be much appreciated!

David
```
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```David:
You can use imline to make the lines (given the endpoints).  Then you
can use the .createMask method of the returned object to "burn it into
an image."  (Search this newsgroup for createMask)  Then you'll have
an image with a bunch of lines written into the pixels.  Then you can
binarize the image and label it with bwconncomp() and measure the
objects with regionprops() to determine a bunch of different things
about the objects, such as area, centroid, etc.  You might also use
bwboundaries() in case you need to scan the boundaries of the object
to determine if the object has 3 sides, or 4 or 5 or 6 etc.
Regards,
ImageAnalyst
```
 0

```Hi,
I want to learn the area of each cell separately on the binary image (not the total):
http://imageshack.us/photo/my-images/62/newarea.png/

Second question is that is there anyway to number the cells on the image according to their sizes?
Do you have any suggestion?
Thanks,
Lauren
```
 0

```Lauren:
See by BlobsDemo:
http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

you just need to sort the allAreas array and the index array in the
same way.

```
 0
Reply imageanalyst (7622) 6/7/2011 11:30:24 AM

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