This demonstration shows some common tricks in image comparison – difference view
People with MATLAB experiences would miss the function
imshowpair, but in JuliaImages it is not that indispensable.
using Images using TestImages img = float.(testimage("cameraman")) # rotate img by 4 degrees and keep axes unchanged img_r = imrotate(img, -pi/45, axes(img))
mosaicview is a convenience tool to show multiple images, especially useful when they have different sizes and colors.
mosaicview(img, img_r; nrow=1, npad=20, fillvalue=colorant"white")
In some cases, when the differences of two images are relative insignificant, a plain substraction can help amplify the difference.
plain_diffview = @. img - img_r
For gray images, a fancy trick is to fill each image into different RGB channels and make a RGB view
RGB_diffview = colorview(RGB, channelview(img), channelview(img_r), fill(0., size(img)))
or convert the RGB view back to Gray image after that
Gray_diffview = Gray.(RGB_diffview) mosaicview(plain_diffview, RGB_diffview, Gray_diffview; nrow=1, npad=20, fillvalue=colorant"white")