Update README.md

README.md

 # python3-escher-pattern
 
-Escher or checker board pattern generator
+Generates:
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+* Escher pattern
+* Checker board pattern
+
+Used for camera systems optical calibration.
+Outputs is a PDF file. No borders. Ready for printing.
+
+# Recommendations
+
+* Overall pattern rotation angle 0 is bad for correct MTF 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