A facsimile broadcasting system is one of the new broadcasting systems. NHK SCIENCE AND TECHNICAL RESEARCH LABORATORIES has developped a digital facsimile broadcasting system. Its signals are transmitted through the Data-channel of the Direct Broadcasting Satellite. The main feature of the system is the stable transmission characteristics and the compatibility with the G3 facsimile receiver. The paper discrives a layer model of the system, the facsimile transmitter and the facsimile receiver. The other feature of the system is as follows. (1) High transmission efficiency through the Data-channel. (2) The received picture quality is 4.5 at a C/N=6.5dB, (3) Clearness of the received pictures, (4) Compact style of the facsimile receiver. The system may apply to the Data-channel of the terrestrial broadcasting systems.
A new method of hierarchical encoding is proposed, which is based on Arithmetic coding with Marcov models. In this method, a crude version of the image is transmitted first, and the details are added gradually, so that the receiver can quickly recognize the outline of the image. With this method, the coding efficency is about 15 percent better than with the standard coding scheme for facsimiles. The key technique is the special Marcov models for hierarchical encoding with which the pixels in the lower resolution level are also referenced.
There are some halftone processing methods which can represent both grey-scale images and bi-level images well. However, they reproduce low contrast images poorly. This report proposes a halftone processing method which can reproduce all image types, including low contrast character image, with high quality. This is performed by automatic contrast detection of these images, and by automatic processing parameter control.
This parer describes a modified technique for Block Truncation Coding and its application to color images. The technique uses a 1-4 level adaptive quantizer based on the K-means clustering method over small block (local regions) of images. The technique is applied to color images by using a new two dimensional Plateau Coding which is a method for efficient coding the chromatic component. The paper presents the obtained good performance of the technique for typical color images.
カラー画像データとして, 各画素毎に(R.G.B)信号値が与えられた時に, これをMunsell表色系における(H.V.C)信号値に充分な精度で変換する式を与えた。この関数は, 多数の色サンプルと重回帰分析の手法を用いて求めたもので, 従来提案されている変換関数に比べ, 充分変換精度の高いことを確認した。また, この過程で得られた表色系"ATM"(Arithmetically Transformed Color Space to Munsell Color Space)は, CIE(1976)Lab表色系よりはるかに均一性の良い直角座標系であるので, 多方面への応用が期待できる。
A method of extracting the region of a car number plate by computer picture processing is described in this report. Our former report has already proposed a Hough transformation in which parameter plane is restricted. This method reduces the computation time and the storage capacity. This report proposes a fast Hough transformation using pyramid hierarchy. This method is reduces more the computation time than the former method. This method is applied to a car number plate extraction algorithm, which uses the features of a car number plate.