초록 ▼

A threshold determination/binarization circuit and a recording medium for an information reproduction system, wherein the diameter of a reference dot detected by a reference dot diameter detection section is compared with a predetermined dot diameter as a standard value, and the threshold is adjuste

A threshold determination/binarization circuit and a recording medium for an information reproduction system, wherein the diameter of a reference dot detected by a reference dot diameter detection section is compared with a predetermined dot diameter as a standard value, and the threshold is adjusted such that the difference between the reference dot diameter and the standard value equals a predetermined target value, thereby obtaining the same binarization effect with respect to image signals obtained with different transfer characteristics (different media, recording states, and optical systems). This circuit also includes a maximum/minimum value detection section that detects the maximum and minimum values of an image signal level corresponding to a dot code. A threshold is calculated by using an internal ratio representing the radio between the maximum and minimum values so as to stabilize a reading operation against illumination and recording irregularity, contamination of a dot code, and the like. On a dot code recorded on a recording medium, attribute dots, each containing information associated with the recording medium, are arranged in a predetermined area on the reading start end side to set a threshold for binarization.

대표청구항 ▼

[ What is claimed is:] [1.] An information reproduction system comprising:reading means for reading a dot code from a recording medium on which multimedia information including at least one of audio information, image information and digital code data is recorded as an optically readable dot code;bi

[ What is claimed is:] [1.] An information reproduction system comprising:reading means for reading a dot code from a recording medium on which multimedia information including at least one of audio information, image information and digital code data is recorded as an optically readable dot code;binarization means for binarizing an image signal corresponding to the dot code read by the reading means using a threshold so as to produce binary image data; andrestoring means for restoring data as original multimedia information by reading a dot code from the binary image data produced by the binarization means,said recording medium including a plurality of reference dots used by said binarization means for determining said threshold, andsaid binarization means including:means for detecting maximum and minimum values of an image signal level corresponding to the dot code;means for setting an internal ratio representing a ratio between the maximum and minimum values of the image signal level;means for calculating the threshold using the internal ratio and the maximum and minimum values of the image signal level;reference dot detection means for detecting the reference dots from the binary image data based on the calculated threshold; andthreshold setting means for determining an estimation value based on diameters of the reference dots detected by the reference dot detection means, for comparing the estimation value with a predetermined reference value and for re-setting the threshold by varying the internal ratio such that a difference between the estimation value and the predetermined reference value becomes equal to a predetermined target value.