METHOD AND DEVICE FOR EXTENDING DYNAMIC RANGE OF PICTURE

• Main Author: WAJIMA HIROSHI
• Format: Patent
• Language: English
• Published: 04.11.1998
• Edition: 6
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PROBLEM TO BE SOLVED: To make the change of a density level natural without generating the pseudo contour of pictures by using an exposure coefficient and correcting the picture data of a different exposure to the picture data to be a reference. SOLUTION: In memories M1-M3, the picture data respectively image-picked up by an intermediate exposure, a large exposure and a small exposure are stored. When it is judged in a judgment circuit 16 that the picture data are present on the outside of the stipulated range of a dynamic range for the density level of the picture data stored in the memory M1, respective arithmetic units 17 and 18 use the picture data of the memory M1 and the picture data of the memories M2 and M3 and compute and obtain a density level difference and the exposure coefficient. The obtained density level and exposure coefficient are supplied to density conversion circuits 24 and 25, the density level on the outside of the stipulated range among the picture data stored in the memory M1 is converted the picture data after correction and the dynamic range is extended.