MATLAB: Removing area

arearegion

I have a code like this.

CC = bwconncomp(I2);

STATS = regionprops(CC,'Area');

idx = find([STATS.Area] <100);

I2(idx)=0;

figure,imshow(I2)

the objective of this code is to set zero value to those pixel whose area is less than 100.

I am not sure whether it is working properly. But perhaps Its not the correct way to achieve may objective.

can any one help how to do that? Thanks

Best Answer

STATS = regionprops(CC,'PixelIdxList','Area');
I2(cell2mat(cellfun(@(x)x',{STATS([STATS.Area]<100).PixelIdxList},'un',0)))=0;

Related Solutions

MATLAB: Applying Regionprops to Only the Region of Interest

Since it looks like you want even partial circles and the only criteria is that the circle centers lie within the polygon the user drew, I'd use inpolygon() to determine which measurements are inside. So if you have xCenters and yCenters arrays, and arrays of vertices, xv and yv, i'd do this

keeperIndexes = false(1, length(xCenters));
for k = 1 : length(xCenters)
    if inpolygon(xCenters(k), yCenters(k), xv(k), yv(k))
        keeperIndexes(k) = true;
    end
end
% Now extract only those that are inside the polygon
roix = xCenters(keeperIndexes);
roiy = yCenters(keeperIndexes);
roiRadii = radii(keeperIndexes);

MATLAB: How to calculate the area of different labels and remove the labels with smaller area?

CC is a struct including the field PixelIdxList. If you define the area as number of pixels, you just need the number of elements of each cell:

 elemsize=cellfun(@numel,CC.PixelIdxList);

To remove the small ones (I define "small" as "less than 100 pixels"):

 BW2=BW;
 BW2(vertcat((CC.PixelIdxList{cellfun(@numel,CC.PixelIdxList)<100})))=0;

You can of course do this without copying BW (just ignore the first line and use BW instead of BW2 in the second line).

Edit: If you also want to remove these from CC:

 CC.PixelIdxList(cellfun(@numel,CC.PixelIdxList)<100)=[];
 CC.NumObjects=numel(CC.PixelIdxList);

Best Answer

Related Solutions

MATLAB: Applying Regionprops to Only the Region of Interest

MATLAB: How to calculate the area of different labels and remove the labels with smaller area?

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