When dealing with real data, Fourier Transform produces symmetric results and FFT algorithms discards half of it. An input with 1024 points will yield only 513 points in the output.
However, in image processing, when Fourier Transform is calculated, the size of the output image is same as that of the input image. Assume that the images are 2D. The (pixel) value of image function
f(x, y) is still real. So, why do we still have an output image size same as input?