Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1987-04-15
1989-04-25
Groody, James J.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358135, 358136, 382 56, 375 27, 364725, H04N 712
Patent
active
048252859
ABSTRACT:
In the hybrid encoder for video signals described the picture elements of a video picture are arranged into equally large data blocks and each newly entered data block, is compared with a data block of the previous video picture by means of a subtractor (SR). The data blocks of the previous picture are stored in a picture store (BS). In order to maintain the transmission bit rates as small as possible, the data blocks are conventionally subjected to a transformation (for example, a Fourier transformation) (F) and a subsequent quantization (Q). For the required strong bit rate reduction a rough quantization is necessary, which leads to a strong quantization noise. To eliminate the quantization noise a blockwise adaptive low-pass filtering (T,FTI) is performed in two signal paths of the hybrid encoder. The quantizer (Q) may then have a refined design or it may be omitted altogether. The result of the low-pass filtering (T,FTI) is a low-definition video picture which is, however, free from the occasionally occurring picture distortions caused by the quantization noise.
REFERENCES:
patent: 4051530 (1977-09-01), Kuroda et al.
patent: 4093994 (1978-06-01), Nussbaumer
patent: 4245248 (1981-01-01), Netravali et al.
patent: 4281344 (1981-07-01), Mounts et al.
patent: 4460923 (1984-07-01), Hirano et al.
patent: 4700226 (1987-10-01), Acampora
patent: 4706260 (1987-11-01), Fedele et al.
"Group Theory and Its Application to the Quandum Mechanics of Atomic Spectra", Wigner et al., 1959, pp. 1-30.
"Digital Image Processing", Pratt, 1987, pp. 242-247.
Speidel Joachim
Vogel Peter
Groody James J.
Maser Thomas O.
Peng John K.
United States of America as represented by the Director of the N
Utermohle John R.
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