Encoding of still pictures by a wavelet transform and singular value decomposition
This paper proposes a new scheme for picture compression which decomposes a picture to (3/spl times/3+1) subband pictures using the 2-D discrete wavelet transform three times, and then decomposes a picture block matrix A(16/spl times/16 pixels) of the lowest frequency subband picture to singular values and eigenvectors of AA/sup T/ and A/sup T/A and encode them by PCM. For all other subband pictures, first we encode the 0-level wavelet coefficient run-length by a modified Huffman code and then encode the non-0-level coefficients by PCM with non-linear quantizer.
SQUEEZING OF COLOR IMAGE USING SELECTIVE ROTATION BASED PRELIMINARY PLAN
In this paper, for a perfect and effective image squeezing, the direction selective image squeezing preliminary plan is introduced. This preliminary plan performs the collective directional transform in sometime depends on plan and sometimes seeming unfair direction and get a transform coding gain. By using this phenomena, easily maximize the energy compaction. For this compaction, firstly determines the maximum energy direction of an image and after that the sinc interpolation method or three pass algorithms is used for rotating the image and after that the conventional 2-D wavelet transform are used for decomposition of image. The convolution method or lifting method is used for conventional wavelet transform. It outperforms JPEG2000 for typical test image.
Numerical Simulation of Thermal Sensitivity for Explosives
In order to compare the thermal sensitivity of several typical explosives, this article solved numerically one-dimensional transient heat conduction equation including thermal decomposition for explosives with finite difference method. The explicit difference equations under different boundary conditions were established, and the corresponding stability criterion was derived. The ignition times for typical explosives were calculated, which was used to evaluate thermal sensitivity of explosives.