how to segment the gray scale image from background

[Matt J]

It's a very nice picture, but what is your question? And what grayscale image are you refering to? The image you have posted is RGB.

[nadine ahmad]

@Matt J first i want to convert the RGB image to gray scale image then segment the gray scale image by region based or boundary based methods to isoleate the hourses from background (I want hourses be white and the background be black)...can you help me with coding?

Answer 1

[Matt J]

If you're trying to develop a binary map of the horses, I was able to do so decently using the Image Segmenter app:

https://www.mathworks.com/help/images/ref/imagesegmenter-app.html

load horses
imshow(BW)

[nadine ahmad]

@Matt J sir can you write in details what did you do

[nadine ahmad]

@Matt J sir can you write the procces how did you do that.. i want to do the steps in my project

[nadine ahmad]

@Matt J sir are you here?

[Matt J]

I used the image Segmenter app to do the segmentation interactively.

[nadine ahmad]

@Matt J yes sir .. but i want to know the details becaues(hourse.mat) dose not work.. i want to creat a segmenter with the same details you used to give me the same resulte you get..

[nadine ahmad]

@Matt J what did you used Threshold,Graph Cut,Auto Cluster,Find Circles,Local Graph Cut (grabcut),Flood Fill,Draw ROI? what is the method you used ?

[Matt J]

I used combinations of Graph Cut, Flood Fill, and Draw ROI to gradually build up the map. I used them many times in no particular order or pattern that should matter to you, assuming you are segmenting interactively. I'm afraid that none of these tools used by itself will segment the horses in a single stroke, if that's what you were hoping.

[nadine ahmad]

@Matt J sir can you give me your personal email?

[Image Analyst]

Matt: If you click the Export code, won't it export code using all the operations you did? I think it would, though it will probably use the coordinates you clicked on, which may not be in the horse or background for a different image where the horse(s) are in different locations. So it might be able to reproduce this segmentation but might not work for segmenting other images properly.

[Matt J]

Right. Also, since I closed out of the app hours ago, I've no way of Exporting at this point...

Answer 2

[Matt J]

If the purpose here is to do automatic semantic segmentation of many horse images, you will probably need to train a convolutional neural network to do it. For animal recognition, DeepLab-v3+ seems to have good track record, judging by,

https://ai.googleblog.com/2018/03/semantic-image-segmentation-with.html

Matlab does have tools for building and training DeepLab-v3+. This might be a good place to start reading,

https://www.mathworks.com/help/vision/ref/deeplabv3pluslayers.html

Obviously, though, the pre-trained version of the network may not work straight out of the box on your specific image database, so you will probably need to retrain it (or use transfer learning) using many manually segmented images. Therefore, it is well worth getting familiar with the Image Segmenter app, even if it doesn't serve your immediate aims.