code ideas in matlab for agricultural land detection

i am on a project in matlab where my code has to decide whether a image of land is agricultural. image should be a top satellite view of the land. combining functionality of land and matlab workspace i found only one relation that is of color of land in image. how to proceed with the project.

Answer 1

[Image Analyst]

You need to do some more research first into multispectral remote sensing algorithm. For that, go here: http://iris.usc.edu/Vision-Notes/bibliography/contentscartog.html#Cartography,%20Aerial%20Images,%20Remote%20Sensing,%20Buildings,%20Roads,%20Terrain,%20ATR. Once you pick an algorithm and code it up, we can help you with the MATLAB code. We don't do complicated algorithm development here.

[nida]

your hue detection demo was very helpful but how would you decide thresholds for detecting different color s in an image like providing threshold for shades of yellow,shades of red,green in a code irrespective of image knowledge. like a application where input image is unknown but you are prepared with multiple thresholds.

[Image Analyst]

Well that's where the art of image processing comes in: developing algorithms. If you think you can get it done by simple thresholding, like with the interactive thresholding app in my File Exchange http://www.mathworks.com/matlabcentral/fileexchange/?term=authorid%3A31862 then you have to come up with some sort of algorithm to deliver that threshold for a variety of images with a variety of histograms. I don't know what that algorithm might be for your images (even if you post them). You have to figure it out.

[nida]

i created a simple gui for matlab files the three red,yellow,green buttons execute different m files with different images of their own i would like to provide single image through link option and want all three buttons to execute that image only need your help on this

[Image Analyst]

Get the url from the edit field in each button. So each button has this

theURLFilename = get(handles.editLink, 'String');
theImage = imread(theURLFilename);

[nida]

does it need a call in mfiles under that buttons too

[Image Analyst]

I don't know what the means. Please answer these questions:

1. What exactly is "it"?
2. What is mfiles? A variable, like a cell array or something?
3. And when you say "that buttons" - which button or buttons are you talking about?

[nida]

it is the command that you specified for my gui. the buttons red,yellow,green have .m files under them so when they are pressed .m files under them executes.

my question was how can i run those .m files under red,green,yellow buttons for images i choose in browse button.

[Image Analyst]

If those buttons don't do anything other than to call another function in a different m-file, then you just call that other m-file by name passing any arguments and receiving in any return arguments:

[out1, out2] = other_m_file(in1, in2, in3); % or whatever...

[nida]

what about images in browse button that i choose and need to be executed by .m files under red,green,yellow buttons. how i do that.

[Image Analyst]

What about them? You get the name from the edit field and pass it to your m-file like I already showed you.

theURLFilename = get(handles.editLink, 'String');
theImage = imread(theURLFilename);
[out1, out2] = other_m_file(theImage , in2, in3); % or whatever...

Or you can pass just the filename string into your m-file instead of the image array after it's been read in:

theURLFilename = get(handles.editLink, 'String');
[out1, out2] = other_m_file(theURLFilename , in2, in3); % or whatever...

It's really however you want to do it.

[nida]

is there a way to 3d plot a 2d image like from this </matlabcentral/answers/uploaded_files/6759/7.jpg>

to this

</matlabcentral/answers/uploaded_files/6760/2.jpg> and ploting should rely on image data. thanks

Answer 2

[Ryan Johnson]

May or may not be useful for you, but the latest issue of the IEEE Signal Processing Magazine is entirely dedicated to hyperspectral remote sensing and classification.