Sonnet text - illumination gradient.

(son1)

The original image.

(son1thr1)

Result of thresholding son1 at a pixel value of 128.

(son1sub1)

Result of pixel subtracting son2 from son1 and adding an offset of 100.

(son1sub2)

Result of pixel subtracting son2 from son1 using wrapping.

(son1sub3)

Result of pixel subtracting son2 from son1 using absolute difference.

(son1sub4)

Result of applying gamma correction to son1sub3.

(son1thr3)

Result of thresholding son1sub1 at a pixel value of 80.

(son1div1)

Result of pixel dividing son1 by son2.

(son1thr2)

Result of thresholding son1div1 at a pixel value of 160.

(son1adp1)

Result of adaptive thresholding son1 using the mean of a 7×7 neighborhood.

(son1adp2)

Result of adaptive thresholding son1 using the mean-C as a local threshold, where C = 7 and the neighborhood size is 7×7.

(son1adp3)

Result of adaptive thresholding son1 using the mean-C as a local threshold, where C = 10 and the neighborhood size is 75×75.

(son1adp4)

Result of adaptive thresholding son1 using the median-C as a local threshold, where C = 4 and the neighborhood size is 7×7.

©2003 R. Fisher, S. Perkins, A. Walker and E. Wolfart.