Onboard Realization For Radiometric Pre-processing For 'le-gall' Wavelet Filter Based Compression

摘要

The paper presents a novel architecture for implementing onboard pre-processing and wavelet based compressor system for autonomous remote sensing satellite imagery. The radiometric image preprocessing implementation architecture is modeled and evaluated. As the compression ratio increases, the application of LUT on ground is not applicable as the pixel values become dependent on adjacent pixels due to compression. In order to correct video data errors at the data handling system and thereby also ensure satisfactory performance, an impulse noise filter and pixel dropout correction is also proposed using 'weighted interpolation'. The new architecture ensures correction for the radiometric errors prior to compression offering superior quality of images. The realized wavelet based compression (JPEG2000) offers considerable gain in Peak Signal to Noise Ratio (PSNR)for remote sensing as compared to discrete cosine transform (DCT) based compression. The realized system is for band wise compression, as band-to-band registration is difficult, thus restricting the compression to single component. The designed system offers superior performance as compared to 'the existing JPEG based system, in terms of quality for the given data handling rate, power, weight, and volume.