For those of you who would like to use this on smaller images, play around with "DoG:15,100,0". This string refers to implementing a difference of gaussian filter with inner radius of 15 and outer radius of 100 pixels. This is obviously tied to image size. The first number should always be smaller than the second, and my guess is that it should be on the order of the average width of the text. Just a estimation, I don't have the time to test it right now.