Compression And Encryption Arithmetic Design Of Radar Image Based On VxWorks

Voyage Data Recorder which vulgarly called black casket can record oderly ship navigation status output signal ship command and handle control.The vessel black casket is different from the airplane black casket, one hand the vessel black casket has limited capability and on the other hand the vessel has long time work. Video has superiority to other data due to its intuitionistic, but it so large as must be compressed, at the same time encryption can make emulant helpless without the key. This research subject is to compress and encrypt the radar data at the same time.Firstly it introduces the embedded operate system VxWorks and its development environment Tornado2.2, and it realizes the PCI device driver. This article expatiates JPEG2000 compression, comes out the dispersion little wave expressions and the course of the EBCOT. Energy mostly focuses on the low frequency coefficient after the wavelet transform, so encrypt the low frequency coefficient can both save time and reach the good effect.The article uses Logistic chaos mapping to encrypt the wavelet low frequency coefficient and latter uses Cat mapping to change position, realizes the pels value and the pels position change at the same time. So it is impossibility to revert the image after athwart transform, and it attains aim and hard to uncover. The image after encrypted satisfies the request though analyse, with little infection of the compression and arithmetic time, with no infection of the image quality.