基于目标的低码率SAR图像压缩

Low Bit Rate Target-based SAR Image Compression

基于目标的SAR图像压缩关键问题是将自动目标检测与图像压缩算法相结合。提出了以db4小波进行小波域多分辨率恒虚警率(CFAR)检测并嵌入图像编码中,在压缩有损量化前检测出目标区,推导了重要小波系数掩膜公式并据此将每个子带中的系数分成目标与背景两个序列,对目标序列以高比特率ECTCQ编码而背景序列则相反。对MSTAR图像压缩实验结果表明,同一般的SAR图像编码算法W/TCQ相比,低码率下TIC算法目标区SNR高,同时背景信息亦得到保护。

The key to target-based SAR image compression is to corporate ATD algorithm with image coding. A SAR image encoder embedded with a multiresolution CFAR （ constant false alarm ratio） detection algorithm in wavelet domain used db4 is proposed in this paper. Target areas are detected before quantization, Significant wavelet coefficients mask is derived based on db4. The sequences of target areas are encoded with a higher bit rate than those of background. Compression and decompression are done on MSTAR target chips; the quality parameters for target areas are achieved; comparison is made with a conventional SAR image coding algorithm of W/TCQ. Experiments show that SINR of target areas using TIC algorithm with low bit rate are higher than that of using W/TCQ algorithm and context information is preserved.