Title:
EXPOSURE ADJUSTING SYSTEM FOR PICTURE PROCESSOR
Document Type and Number:
Japanese Patent JPH01216681
Kind Code:
A
Abstract:
PURPOSE:To automatically adjust exposure time by counting white dot number of an area decided on a picture data, comparing the count with maximum and minimum permissible values decided in advance, decreasing the exposed time by a prescribed exposure adjustment ratio when the count is too large and increasing the time by the exposure adjusting ratio when the count is tool small. CONSTITUTION:A white dot in a prescribed sample area read from a picture memory 6 is counted by a central processing section 4 and the white dot and the predetermined maximum permissible value are compared. When the white dot number is excessive, the subtraction value of a predetermined exposure adjusting ratio Rad is multiplied with an exposure time TEXP. When the result of determination is too small, the addition of 1 to the exposure adjustment ratio Rad is multiplied with the exposure time TEXP at that time. Then the initial process is restored as a new exposure time TEXP to apply write of the initial value and the readout of the picture data. That is, every time the white dot number changes from the too excessive state into the too small state or vice versa during the adjustment of the exposure time TEXP, the exposure adjustment ratio Rad is halved to quicken the exposure time TEXP to be converged into its permissible range alpha.
Inventors:
FUJIWARA YOSHIMASA
Application Number:
JP4096488A
Publication Date:
August 30, 1989
Filing Date:
February 24, 1988
Export Citation:
Assignee:
MATSUSHITA ELECTRIC WORKS LTD
International Classes:
H04N5/232; G06T1/00; H04N5/235; H04N5/335; H04N5/353; (IPC1-7): G06F15/64; H04N5/232; H04N5/235; H04N5/335
Domestic Patent References:
| JPS559267U | 1980-01-21 |
Attorney, Agent or Firm:
Ishida Choshichi