align

Align 3 images to create RGB image.

Compiling

• make - you need to have go installed.

Installing

• go install github.com/lukaszgryglicki/align/cmd/align (for anybody, no need to have aything more than just go installed).
• make install (requires make tool).

Results

You can create example aligned image via: ./align R.JPG G.JPG B.JPG Aligned.JPG.

You can do the same using ImageMagick's convert: convert R.JPG G.JPG B.JPG -combine Unaligned.JPG.

But convert will not try to aliggn images together, it will only combine channels.

See:

• Aligned:

• Unaligned:

Some details

Supported image types are: PNG, JPG, GIF, TIF, BMP.

Other example: N=16 FROM_X=3000 FROM_Y=2000 RANGE_X=20 RANGE_y=20 SIZE_X=80 SIZE_Y=80 ./align R.JPG G.JPG B.JPG X.bmp.

Defaults: it starts from smalles image center (they're supposed to be the same size) and checks squares 200 pixels size from center (so single check is 200+200+1 = 401x401 = 160801 pixels).

Then it performs movements 64 pixels in all directions (this gives 64+64+1 = 129x129 = 16641/16.6K checks each checking 161K pixels).

To figure out which movement is best it calculates different for two iamges at each pixel (absolute value of their difference. it assumes images are monochrome and just takes a green pixel of image if it isn't monochrome) and then calculates sum of those absolute pixel differences.

Then it chooses minimum from all possible movements range (by default moving 401x401 square from image center in all directions covering 129x129 checks).

You can also override number of (v)CPUs autodetection and specify for example N=8.

You can change those details via environmental variables.

Environment variables:

• N - how many (v)CPUs use, defaults to autodetect.
• BITS8 - save 8bit image instead of 16bit (default).
• FROM_X - where is the x value for image circle to start aligning from (middle of the first image if not specified).
• FROM_Y - where is the y value for image circle to start aligning from (middle of the first image if not specified).
• RANGE_X - how many x pixels check around start x (defaults to 64, which gives 64+64+1 = 129 checks, 129x129 = 16641 checks for X & Y - if set the same).
• RANGE_Y - how many y pixels check around start y (defaults to 64, which gives 64+64+1 = 129 checks, 129x129 = 16641 checks for X & Y - if set the same).
• SIZE_X - how many x pixels check in single pass (defaults to 200, which gives 200+200+1 = 401x401 = 160801 pixels - if x & y pixels set the same).
• SIZE_Y - how many y pixels check in single pass (defaults to 200, which gives 200+200+1 = 401x401 = 160801 pixels - if x & y pixels set the same).
• PXV_SHIFT - shift pixel values in output image (like you have 16bit values but want to shift them to 8, then specify PXV_SHIFT=8).
• Q - jpeg quality 1-100, will use library default if not specified.
• PQ - png quality 0-3 (0 is default): 0=DefaultCompression, 1=NoCompression, 2=BestSpeed, 3=BestCompression.