MATLAB: How can you increase the angular resolution of pixels in a 2 D image fourier transform

2d fourier transform angular resolution pixel resolution image processing

Hi,

i have been doing 2D Fourier transforms on tilted fringe images and I want to know how to increase the angular resolution of the fringes so that I can obtain the fringe angle from the 2D fourier transform. I have tried using interpolation methods like (imresize, interp2) but that didn't get me to the resolution that I needed. I have also tried using resample to increase the sampling rate but that didn't give the result I wanted. Do you know of any ideas that I can use to increase the angular resolution?

An example of an image of the tilted fringe is attached. Thanks!

Best Answer

The pixel resolution is determined and fixed by the size of the image matrix. If you increase the image size using imresize() it will give you more pixels but don't be deceived that this gives you more resolution physically in the real world. You can increase the number of pixels all you want and it won't give you more real resolution. In other words, if an image is blurry, scaling up the number of pixels by a thousand in each dimension will not now suddenly let you resolve points a thousand times closer together. It will still be a blurry image, just bigger.

Related Solutions

MATLAB: How to use imcrop() on an image without losing resolution

The spatial resolution will be the same, in terms of the details you can resolve in the image. The image matrix will be smaller (fewer pixels) of course.

Axes controls will auto-size, to some extent, when you call imshow(). You can change the 'InitialMagnification' parameter if you want to magnify the image upon display but leave the cropped image intact (the same size).

imshow(croppedImage, 'InitialMagnification', 1600);

You can call imresize() if you want to change the number of rows and columns in the cropped image to be something else.

bigImage = imresize(croppedImage, [3000, 4000]);
imshow(bigImage, []);

Be aware though that it may shrink it down to fit into axes that you have on the screen.

MATLAB: How to save a image file to a higher resolution that it actually is

You can use imresize() to increase the pixel count before you write it out. Note that this does not increase the optical resolution - it will look just as blurry, just bigger.

bigMatrix = imresize(originalMatrix, 4); % Blow up by a factor of 4
imwrite(bigMatrix, filename);

You can also blow up images just on display by using the 'InitialMagnification' input parameter to the imshow() function:

imshow(originalMatrix, 'InitialMagnification', 800);

Best Answer

Related Solutions

MATLAB: How to use imcrop() on an image without losing resolution

MATLAB: How to save a image file to a higher resolution that it actually is

Related Question