This paper summarizes a research study on data compression techniques applicable for Remote Piloted Vehicles (RPV). Interframe techniques are considered and algorithms are determined to account for motion in frame-to-frame aerial photographs resulting in large bit reduction ratios provided that the various parameters of the mission such as altitude, velocity, etc. are accurately known. Differential encoding is used to further reduce bandwidth. Intraframe techniques suitable for the RPV mission including two-dimensional transform techniques and hybrid coding schemes are investigated and evaluated. It is shown that the hybrid schemes using Hadamard transform in one spatial direction and DPCM in the other spatial direction performs equivalent and at times superior to 2-dimensional transform techniques. The effects of channel errors on both the transform and hybrid coding schemes are investigated. Although the hybrid coding scheme is shown to be more sensitive to noise, optimization of the prediction coefficient results in satisfactory performance in a noisy environment. An adaptive scheme is considered which shows improved resolution in regions of high activity within the picture.
J. E. Essman,
Q. D. Hua,
N. C. Griswold,
"Video Link Data Compression For Remote Sensors", Proc. SPIE 0087, Advances in Image Transmission Techniques, (13 December 1976); doi: 10.1117/12.954981; https://doi.org/10.1117/12.954981