The Café Wall Illusion: Local and Global Perception from Multiple Scales to Multiscale

Figure 9

(a) A binary DoG edge map at seven scales ( = 4, 8, 12, 16, 20, 24, and 28) of a cropped section of size 4 × 5 tiles from a Café Wall with 200 × 200 px tiles and 8 px mortar. (b) The DoG edge map displayed in the jetwhite color map [37]. (c) Detected houghlines from the edge map displayed in green, overlaid on the binary edge map with Hough parameters as: NumPeaks = 100, Threshold = 3, FillGap = 40, and MinLength = 450 (based on [19]).

(a)

(b)

(c)