A. Yu. Aksenov, A. A. Zaytseva, S. V. Kuleshov
Traditionally in communication theory for estimation of data channel quality and its conformity with transmitted data the energy criteria were used without taking transmitted content properties into account. The transmission of video data via data channel due to technical features of data sources, intermediate stages of data processing and the features of displaying devices has constructive mismatch of transmitted data value regions.
The problem of conformity estimation is considered on example of color channel of video data transmission. If the transmission channel has components which apply video processing including data compression with losses the extra color loss occurs.
For estimation of color range contraction, the following method was applied: the transmission via channel with compression of the image containing full range of distinct colors representable in RGB color space was modeled. Two types of compression were modeled: based on DCT (discrete cosine transform) and based on DWT (discrete wavelet transform) with various compression ratio factor.
Thus the concept of transmission channel to data conformity could be stated as follows: the ratio of number of distinct values of color space after all stages of transmission to the number of distinct values to be represented by displaying device.
The considered method and given criteria can be applied to optimize data channels with compression and to increase of compression ratio without subjective noticeable quality loss.