Method for generating calibration curve
View Patent ↗A method for generating a calibration curve is disclosed. The method comprises the following steps. Calibration data of one line image of a previous scan are first provided. Reference pixels are selected from the image line. Then a calibration board is scanned and calibration data of the reference pixels are generated. Calibration data of the reference pixels of a previous scan are then selected from the calibration data of one image line of a previous scan. Ratios of the calibration data of the reference pixels and the calibration data of the reference pixels of a previous scan are calculated. Calibration data of all pixels of the image line are finally generated by multiplying the calibration data of the image line of a previous scan and the ratios.
1. A method for generating a calibration curve, said method comprising:
providing calibration data of one image line of previous scan;
selecting reference pixels of said image line;
scanning a calibration board;
generating calibration data of said reference pixels;
selecting calibration data of said reference pixels of previous scan from said calibration data of said image line of previous scan;
calculating ratios of said calibration data of said reference pixels and said calibration data of said reference pixels of previous scan; and
generating calibration data of all pixels of said image line to form the calibration curve by using said ratios of said reference pixels.
2. The method according to claim 1 , wherein said calibration board comprises a white calibration board.
3. The method according to claim 1 , wherein said calibration board comprises a black calibration board.
4. The method according to claim 1 , wherein said calibration data of said reference pixels are generated by converting light signals reflecting from said calibration board to analog voltage signals, adjusting said analog voltage signals, converting said analog voltage signals to digital voltage signals and calibrating said digital voltage signals.
5. The method according to claim 1 , wherein said calibration data of all pixels of said image line are generated by multiplying said calibration data of said image line of previous scan and said ratios.
6. The method according to claim 1 , when said ratios are not a constant value, said calibration data of all pixels of said image line are generated by an interpolation method.
7. A method for generating a calibration curve, said method comprising:
providing calibration data of one image line of previous scan;
selecting reference pixels of said image line;
scanning a calibration board;
generating calibration data of said reference pixels;
selecting calibration data of said reference pixels of previous scan from said calibration data of said image line of previous scan;
calculating ratios of said calibration data of said reference pixels of previous scan and said calibration data of said reference pixels;
feeding said ratios in a gain voltage amplifier; and
calibrating analog voltage signals of all pixels of said image line by said ratios in said gain voltage amplifier.
8. The method according to claim 7 , wherein said calibration board comprises a white calibration board.
9. The method according to claim 7 , wherein said calibration board comprises a black calibration board.
10. The method according to claim 7 , wherein said calibration data of said reference pixels are generated by converting light signals reflecting from said calibration board to analog voltage signals, adjusting said analog voltage signals, converting said analog voltage signals to digital voltage signals and calibrating said digital voltage signals.
11. An apparatus for generating a calibration curve, said apparatus comprising:
a charge-coupled device, said charge-coupled device receives light signals and converts said light signals to analog voltage signals;
a direct current gain voltage amplifier, said direct current gain voltage amplifier receives and adjusts said analog voltage signals;
an analog-to-digital converter receives and converts said adjusted analog voltage signals to digital voltage signals;
a calibration means, said calibration means receives and calibrates said digital voltage signals; and
a memory, said memory stores said calibrated digital voltage signals from said calibration means, wherein said calibration means selects calibration data of reference pixels of previous scan from said memory, calculates ratios of calibration data of reference pixels and calibration data of reference pixels of previous scan, stores said ratios in said memory and multiplies said ratios and calibration data of all pixels of previous scan to generate calibration data of all pixels.
12. An apparatus for generating a calibration curve, said apparatus comprising:
a charge-coupled device, said charge-coupled device receives light signals and converts said light signals to analog voltage signals;
a direct current gain voltage amplifier, said direct current gain voltage amplifier receives and adjusts said analog voltage signals;
an analog-to-digital converter receives and converts said adjusted analog voltage signals to digital voltage signals;
a calibration means, said calibration means receives and calibrates said digital voltage signals; and
a memory, said memory stores said calibrated digital voltage signals from said calibration means, wherein said calibration means selects calibration data of reference pixels of previous scan from said memory, calculates ratios of calibration data of reference pixels of previous scan and calibration data of reference pixels, feeds said ratios back to said direct current gain voltage amplifier.