A hybrid motion estimation technique for fisheye video sequences based on equisolid re-projection
This addresses motion estimation challenges in surveillance and automotive applications using fisheye imagery, but it is incremental as it builds on existing methods.
The paper tackles motion estimation in fisheye video sequences by introducing a hybrid method that uses equisolid re-projection and combines it with conventional techniques, achieving average gains in luminance PSNR of up to 1.14 dB for synthetic data and 0.96 dB for real-world data.
Capturing large fields of view with only one camera is an important aspect in surveillance and automotive applications, but the wide-angle fisheye imagery thus obtained exhibits very special characteristics that may not be very well suited for typical image and video processing methods such as motion estimation. This paper introduces a motion estimation method that adapts to the typical radial characteristics of fisheye video sequences by making use of an equisolid re-projection after moving part of the motion vector search into the perspective domain via a corresponding back-projection. By combining this approach with conventional translational motion estimation and compensation, average gains in luminance PSNR of up to 1.14 dB are achieved for synthetic fish-eye sequences and up to 0.96 dB for real-world data. Maximum gains for selected frame pairs amount to 2.40 dB and 1.39 dB for synthetic and real-world data, respectively.