| 摘要 |
PURPOSE:To improve an accuracy for correcting a picture, and an operating speed by bringing a picture signal inputted from each cell of an array sensor and logarithmically converted by eliminating a dark time component, to an addition/subtraction processing by a white level reference signal read out at every corresponding cell. CONSTITUTION:An output signal (vi) of a camera 1 provided with a CCD sensor is supplied to an A/D converter 3 and an adding and subtracting circuit 4 through a changeover switch (S)2. As for a dark time component, a position of each cell is made an address and the corresponding component is recorded in a memory 5. The circuit 4 eliminates the dark time component from the signal (vi) of the corresponding cell and inputs it to a logarithmic converting circuit 7. An output of the circuit 7 is connected to an adding and subtracting circuit 10 and 9 through an S8. A white level reference signal read out at every corresponding cell is stored in a memory 12 after a non-varied component is eliminated in the circuit 9. The circuit 10 corrects a sensitivity correcting value DELTACi and outputs a signal logR depending on onlyh a reflection factor or a transmission factor of an original. In this way, an accuracy for correcting a picture and an operating speed can be improved. |
