HoughlinesP accumulator

Hi guys,

I needed access to the accumulator info from HoughLinesP so I altered the code to return the accumulator. When I go to print the accumulator Mat it has mostly negative values in it (well mostly 0’s but the accumulated values are mostly negative). I don’t understand that. Usually you would start with it full of 0’s and accumulate positive votes? There are a few positive values as well so it’s not that they chose to accumulate in the negative. Any ideas of how to interpret this? I’m trying to visualize the Hough accumulator as an image BTW.

Thanks!