how to apply mask on image

I am making mask of one's and I want this mask to walk on the image to get the average of the Pixels under the mask.and complete to the full image size. mask size[3,3] image size [400,400]

Answer 1

[Andrei Bobrov]

try this function

or this

Answer 2

[Image Analyst]

Try convolution:

filteredImage = conv2(grayImage, ones(3)/9);

You can do the same thing with imfilter().

[Thulitha Theekshana]

Remember to convert the output of conv2 to uint range. ( maybe using a function such as mat2gray ) before imshow. Otherwise the image wouldn't be displayed.

[Image Analyst]

In my code, grayImage needs to be a single or double. If it's a uint8 you will need to cast to double or single before passing in to conv2():

filteredImage = conv2(double(grayImage), ones(3)/9);

Then filteredImage will be a single or double. To display it without casting back to uint8, you can use [] in imshow(), like this:

imshow(filteredImage, []); % Brackets needed if the floating point image is not in the range 0 to 1.

or you can just cast it back to uint8:

filteredImage = uint8(conv2(double(grayImage), ones(3)/9));
imshow(filteredImage); % Brackets not needed if it's uint8