This paper presents a two layer CODEC architecture for high dynamic range video compression. The base layer contains the tone mapped video stream encoded with 8 bits per component which can be decoded using conventional equipment. The base layer content is optimized for rendering on low dynamic range displays. The enhancement layer contains the image difference, in perceptually uniform color space, between the result of inverse tone mapped base layer content and the original video stream. Prediction of the high dynamic range content reduces the redundancy in the transmitted data while still preserves highlights and out-of-gamut colors. Perceptually uniform colorspace enables using standard ratedistortion optimization algorithms.
We present techniques for efficient implementation and encoding of non-uniform tone mapping operators with low overhead in terms of bitstream size and number of operations. The transform representation is based on human vision system model and suitable for global and local tone mapping operators. The compression techniques include predicting the transform parameters from previously decoded frames and from already decoded data for current frame. Different video compression techniques are compared: backwards compatible and non-backwards compatible using AVC and HEVC codecs.
All acoustooptic (AO) devices are based on the inherent nonlinear dependence of the light diffraction efficiency as a function the acoustical wave intensity. In AO devices using a single frequency acoustic wave it is easy to be taken into account to describe all functional properties and limits of the first order diffraction. But in many practical devices using multi-frequency sounds like AO signal processors or multipoint AO deflectors the description are a very complicated, because of a very strong frequency intermodulations. These effects give functional disadvantages in the AO implementations- the decrease of the first order diffraction efficiency maximum to much less than 100%, the appearance of spurious orders and etc. In this work there were developed the theoretical arguments for the possibility to have the appropriate signal dynamic predistortions to have a serious change of mentioned intermodulations and to obtain some advances in limitations of many existing AO devices. The proposal uses the new technique by authors for synthesis and programmable dynamic changes of all RF signals performing the preliminary electronic signal treatment to cancel a certain diffraction modes. The experimental verifications with AO modulators based on TeO2 crystal have been performed. With use of the analogue third order polynomial RF synthesizer there were obtained a good suppression up to 10-15 dB of two-tone second-order intermodulations in area of second order diffraction and two-tone third order spurious modes in the first order diffraction area, in accordance with proper theoretical calculations. There was also verified new technique providing maximal optical power in multi beams laser diagram. In TeO2 AO modulators the growth of the efficiency of two-beam He-Ne laser about 14% was obtained.
In a number of applications the approximation, interpolation or nonlinear extrapolation of certain weakly (when every subsequent term of power series expansion is much less than previous one) nonlinear dependencies d(x), where x an arbitrary signal in time, is demanded. The problem of cancellation of nonlinear distortions of a signal in high precision analog engineering can be an example. In such cases it seems to be reasonable to use polynomial-based devices. In this paper the neural network based devices able to perform the operations of approximation, interpolation and nonlinear extrapolation are described. The schemes and working characteristics of a breadboard, based on analog radio components, are presented. Legendre polynomials were offered as basis functions for significant increasing of the speed of the approximator training. The scheme of analog synthesizer of Legendre polynomials was also suggested.
For optically resonant systems, the intermodulation amplitudes of the 2nd and 3rd orders in approximation of small diffraction efficiency for the two main AO interaction regimes: 'thin' and 'thick' gratings are for the first time calculated. It is shown, that the photoelastic nonlinearity causes in general case the complexity of intermodulations. However, under certain conditions, the effect of compensated intermodulation can take place. It yields to the possibility of remarkable growth of the dynamic ragne value which is a great importance parameter for many AO devices.