Automatic Assessment of the Quality of Group 3 Facsimile Transmission

摘要

Group 3 facsimile equipment transmits an end of line code (EOL)which uniquely defines the end of one scan line and the beginning of the next. In a sense this code is redundant information and therefore can be used to detect the occurrence of a transmission error in the scan line immediately preceding the EOL code. Stated another way, if the EOL code does not occur at the anticipated location in the data stream, it is assumed that a transmission error has occurred in the preceding scan line. If one isolated scan line is in error, the subjective effect is usually minimal and the information content is maintained. If however, many scan lines in a row are perturbed the image could be seriously distorted with the attendant user dissatisfaction. It is possible for the receiver to detect the occurrence of a scan line error, accumulate this information for many lines, and terminate transmission if too many scan lines are in error. The purpose of this study is to develop test data to determine the algorithms for accepting or rejecting an image transmission using scan line error data.