Block Truncation Coding (BTC) is a simple and fast lossy image compression technique for digitized gray scale images. In this paper, a novel idea for further reducing the bit rate is introduced. The BTC and its two other variants, one being the Absolute Moment Block Truncation Coding (AMBTC) are discussed and the proposed idea is incorporated in all the three methods. A bitrate of 2 bpp is achi...

This paper considers balanced truncation of discrete-time Hankel $k$-positive systems, characterized by matrices whose minors up to order $k$ are nonnegative. Our main result shows that if the truncated system has or less, then it is totally positive ($\infty$-positive), meaning a sum first lags. can be understood as bridge between two known results: property first-order ($k=1$), and preserves ...

systems in which reaction terms are coupled to diffusion and advection transports arise in awide range of chemical engineering applications, physics, biology and environmental. in these cases, thecomponents of the unknown can denote concentrations or population sizes which represent quantities andthey need to remain positive. classical finite difference schemes may produce numerical drawbacks s...