Difference between revisions of "Kifu: Go game record (kifu) generator"

Revision as of 06:12, 10 August 2008

Image change detection:

Using vertical and horizontal RGB components sums of a thresholded difference between a reference image and the current one,

it is easy to compute the screen coordinates of a played stone

Geometric projection:

It is necessary to map each point from a reference rectangle to a point in the displayed shape, or vice-versa;

without considering scene, camera or observer parameters.

The only data available are the corner coordinates on the projection plane and the reference rectangle proportions.

Grid intersection detection:

As the camera has not been calibrated, the projected coordinates are somewhat approximative.

So it is necessary to detect the nearest grid intersection for each computed grid point.

Methods for mapping the coordinates:

"2.2 Perspective transformation with two vanishing points" (pages 2 and 3, equations 7 and 10)

Inverse homography and plane image rectification (page 14)

"Inferring Projective Mappings" (page 3)

Links:

irc://irc.freenode.net/#kifu

Photointerpretation and Small Scale Stereoplotting with Digitally Rectified Photographs with Geometrical constraints: http://cipa.icomos.org/fileadmin/papers/potsdam/2001-21-gf01a.pdf

@@ Line 13: / Line 13: @@
 The only data available are the corner coordinates on the projection plane
 and the reference rectangle proportions.
+'''Grid intersection detection:'''
+As the camera has not been calibrated, the projected coordinates are somewhat approximative.
+So it is necessary to detect the nearest grid intersection for each computed grid point.