llinescan/readme.md

Strip Photography / Slit Photography

A digital implementation of strip photography (also called slit photography) that captures a two-dimensional image as a sequence of one-dimensional images over time.

How it works: Strip photography records a moving scene over time using a camera that observes a narrow strip rather than the full field. This implementation simulates the technique by extracting the same line position from each video frame and assembling them into a composite image where:

• One axis represents space (the slit/line being observed)
• The other axis represents time (progression through video frames)

Visual effects:

• Moving objects appear as visible shapes in the final image
• Stationary objects (like background) appear as horizontal/vertical stripes
• Object width is inversely proportional to speed (faster = narrower, slower = wider)

Usage

Column Mode - Extract vertical lines (columns) from each frame:

uv run main.py test1.mkv --xcolumn 100 --output test1_column.png

Row Mode - Extract horizontal lines (rows) from each frame:

uv run main.py test1.mkv --yrow 200 --output test1_row.png

Configure

We use uv to handle pip dependencies. Install with:

uv sync

Output

• Column mode: Extracts vertical line at x-coordinate from each frame
  • Output dimensions: (source_height, total_frames, 3)
  • Width = number of frames, Height = source video height
• Row mode: Extracts horizontal line at y-coordinate from each frame
  • Output dimensions: (total_frames, source_width, 3)
  • Width = source video width, Height = number of frames

Each column/row in the output represents one frame from the input video, showing motion over time.