focus-stack

Focus Stack

This program generates focus stacked images and depth maps given a set of images taken at different focal depths. Additionally, it creates a depth map that can be used to turn the image 3D.

This is commonly done in microscopy to generate images of a full specimen.

Example, top row is the input and the bottom is the stacked iamge and depth.

Stacked together using Depthy it looks like this:

https://github.com/josephlewis42/focus-stack/assets/696193/fdf8a2f9-e797-4d44-9a52-ab3e9f7b5476

Installing

Install using go install:

go install github.com/josephlewis42/focus-stack@latest

Or, download the repsitory and use make, the binary will be in ./bin/focus-stack:

make build

Running

focus-stack img1.png img2.png img3.png

Arguments should be a list of PNG or JPG images starting from the image farthest back.

Flags:

• -d string Output file for depth map. (default depth.png)
• -o string Output file for stacked image. (default stacked.png)

Example:

focus-stack \
   -d example/leaves/depth.png \
   -o example/leaves/stacked.png \
   example/leaves/*sm.png

Limitations

• Images must be of the same size and JPG or PNG encoded.
• Images should be taken from a fixed camera position.
• The algorithm may not work on extremely large images.

Technique

Images are read in, converted to grayscale, then have a Laplacian of Gaussian filter applied to determine sharpness of each pixel.

Contributing

Contributions are welcome! Some ideas:

• Adding the ability to embed depth metadata in the output image.
• Adding a built-in viewer.
• Improving performance for very large images -- use the --cpuprofile flag to capture before/after snapshots.
• Adding tuning to the kernel parameters.

License

Licensed under the MIT License.