Remap on CUDA

Remap option can fix lens distortions, rotations and also can correct color differences between channels at the same time. We can do remap for every image component either separately or alltogether.

We've implemented remap feature on GPU and it's working very fast. To see live benchmarks, we would suggest to download Fast CinemaDNG Processor software to see quality and performance.

Here you can see our solution for FFmpeg Remap Filter which has the same code, but is intended for streaming applications in connection with FFmpeg or libav.

Applications for Remap

• Radial and tangential undistortion
• Chromatic aberration removal
• Image rotation on arbitrary angles
• Dewarping for cylinder or spherical projections
• Affine and Perspective transforms
• Arbitrary projections via 2D maps

Standard Remap Procedure

• Capture set of images with chess pattern for calibration purposes
• Calculate set of coefficients and image center position
• Calculate offsets from expected positions (with predefined steps for X and Y)
• Create two maps: one with X offsets and one with Y offsets
• Remap can directly interpret these two offset tables and change the pixel positions accordingly
• All new pixels will be interpolated (linear, cubic or lanczos)