Image Rotation, Line Symmetry

Here is another approach using a background to prevent cropping of the rotated image when its aspect ratio is far from 1:

im = Import["http://i.stack.imgur.com/pyNu2.png"]

img

im2 = SetAlphaChannel[im, ColorNegate[im]];
bg = ImageCompose[
   Rasterize[
    Graphics[{Lighter[Orange], Rectangle[{0, 0}, {1, 1}]}, 
     PlotRange -> {{0, 1}, {0, 1}}], "Image", ImageSize -> 600], im2];

Manipulate[
 Show[ImageCompose[bg, ImageRotate[im2, angle, {600, 600}]]], {angle, 
  0, 2 Pi}]

manipulate

Edit

If you want smooth blending instead of a sharp alpha channel as I did in the first approach, you could do this:

crop = Rasterize[
   Graphics[{White, Disk[]}, PlotRange -> {{-1, 1}, {-1, 1}}], 
   "Image", ImageSize -> 600, Background -> Black];

Manipulate[
 SetAlphaChannel[
  ImageCompose[bg, {ImageRotate[bg, angle, {600, 600}], .5}], 
  crop], {angle, 0, 2 Pi}]

man2

Here, I added another cropping mask in the form of a disk to prevent the partially uncovered corners from showing.


Something like this maybe:

image = ImageResize[ExampleData[{"TestImage", "Lena"}], 200];

Manipulate[ImageCompose[image, {ImageRotate[image, a], 0.5}], {a, 0, 2 Pi}]

enter image description here

Tags:

Graphics

Import

Image Processing

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