I am trying to detect scale space extrema in my 3D volume. I am generating mipmaps for the Gaussian pyramid. Then I use FBO and a fragment shader to calculate the DoG (Difference of Gaussian). This works ok but I use keyboard to move through slices and across mip levels. I am currently displaying the result on the screen and its fine. Now the thing I want to do is to store the DoG for all the slices and the different mipmaps (scales) into another 3d volume. My questions are
- How do I readback this data?
- Is it possible to read back data from a bound FBO?
- Is it possible to directly dump the data into a 3D texture in the fragment shader?
- Can u think of any way whereby I can detect the extrema points directly without storing the DoG images?