python3-escher-pattern

Online examples:

• Escher - 1524x3048 mm, ~14° CW rotation, ~4 periods total
• Checker board - 1524x3048 mm, ~14° CW rotation, ~4 periods total

Generates:

• Escher pattern
• Checker board pattern

Used for camera systems optical calibration. Outputs is a PDF file. No borders. Ready for printing.

comparison

• Escher pattern provides better Point Spread Function (PSF) localization

Recommendations

• Overall pattern rotation angle 0 is bad for correct PSF computation - because sensor pixel grid

Requirements

• matplotlib

Usage

Docker

docker build --tag ep .
docker run -d -p 3113:5000 ep

Then:

http://localhost:3113/?PAGE_WIDTH=1524&PAGE_HEIGHT=3048&LPM=2.705449885575893&ROTATE=14.036243467

Parameters:

• PAGE_WIDTH - page width in mm
• PAGE_HEIGHT - page width in mm
• LPM - cell pairs per meter
• ROTATE - pattern rotation angle
• ESCHER - cell border curvature - at 0 or inf becomes a normal checker board. Max curvature is at ~2.4. Optimal - 2.0

Command line

escher.py:

from escher_pattern import Escher_Pattern
ep = Escher_Pattern(width= 1524, height= 3048, escher=2, lpm=2.705449885575893, rotate=14.036243467)
ep.generate()
ep.save()

checkerboard.py:

from escher_pattern import Escher_Pattern
ep = Escher_Pattern(width= 1524, height= 3048, escher=0, lpm=2.705449885575893, rotate=14.036243467)
ep.generate()
ep.save()

Parameters:

• width - page width in mm
• height - page width in mm
• lpm - cell pairs per meter
• rotate - pattern rotation angle
• escher - cell border curvature - at 0 or inf becomes a normal checker board. Max curvature is at ~2.4. Optimal - 2.0