| Down Hole Video is a logging instrument used to obtain downhole image in oil field, which developed on aboard have made successful application, and gained great commercial benefits. It is just beginning research in downhole video logging instrument field in our country. High quality, low bit rate image compression method is one of the key technologies to develop downhole video logging instrument. A project adapt to downhole video image compression is proposed by author in this paper. The project is based on wavelet transform image compression, and implements wavelet transform, subband coding, The quantization and entropy encoding processes provide data compression; The image compression algorithm realized by hardware, technologies of compression ratio control, quality box, Frame Rate Reduction are used in the process of image compression, achievement high quality, low bit rate image compression; According to using environment and channel transmitting rate, parameters of image size, frame rates, compression rate can be adjusted to compromise between definition and continuity to achievement the most ideal image compression. Experiment result testified that continuous moving pictures with great quality can be obtained using the method mentioned in the paper, met the requirement of downhole video to image compression, resolved the key technological problem of down hole video image compression. And the project have the advantages of simple, low working frequency, low software complexity, working reliable etc, has certain reference value to other special image compression system. |
PDF Full Text Request