MATLAB: Image Processing

image processing

I would greatly appreciate help with coding the following image processing steps in matlab: – loading in an analyze image (type:hdr/img) and binarize it (BW image and the ROI are the white areas) – For each "white area" (defined either by a 1 or 0), create its own separate mask

I am having trouble flowing each step into the other and figuring it out. I have some experience with MATLAB but I am really having trouble with this combination. I would greatly appreciate anyone's help!

Thank you in advance!

Best Answer

Look at my BlobsDemo - it does all that. Well, different image format (not hdr/img - whatever that is) but basically it finds and measures objects.

http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862

You should get the Image Processing Toolbox. It will be hard to do much image processing without it unless you love to spend lots of time reinventing wheels and things.

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MATLAB: Sizing of Poly Objects in an Image

Try

taking the red channel.
threshold to get all the blue jewels
take the convex hull with bwconvhull so that you have only one blob.
erode with imerode until you've gone enough to get inside the outer ring.
Use those two binary images to get a mask of just the outer ring. Use xor().
Use the ring mask to mask the red image.
Use regionprops() to get the center of the convex hull mask.
Use improfile and bwboundaries to get the mean gray level of the ring for every angle around the ring.
Examine the mean gray level as a function of angle to find the dividing lines between blob on the ring.

MATLAB: Help understanding the imbothat function.

edit imbothat

will show you that your above imsubtract(imclose)) suspicision is indeed correct. As for understanding it, let's take Brett's blog post from a little time ago:

http://blogs.mathworks.com/pick/2012/04/27/calculating-arclengths-made-easy/

And let's say that hypothetically we were not able to segment the whole eye, and that the blood vessels appeared as part of the background in a binary image. Granted this would be very easy for this image, but just as a concept, if there wasn't the contrast and some internal features were showing up as not part of the object. So how do we find those blood vessels? Well we could do a bottom hat filtering which would morphologically close the image (dilate then erode (fill the blood vessels but not unfill them!)) and then subtract this from the original image.

hth

Best Answer

Related Solutions

MATLAB: Sizing of Poly Objects in an Image

MATLAB: Help understanding the imbothat function.

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