Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Reexamination Certificate
1998-11-30
2003-12-16
Lee, Cheukfan (Department: 2622)
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
C358S445000, C358S444000, C382S274000
Reexamination Certificate
active
06665096
ABSTRACT:
CLAIM OF PRIORITY
This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C §119 from an application entitled An Apparatus And Method For Processing Image earlier filed in the Korean Industrial Property Office on Nov. 29, 1997, and there duly assigned Serial No. 97-64374 by that Office, and an application entitled An Apparatus And Method For Processing Image earlier filed in the Korean Industrial Property Office on Dec. 17, 1997, and there duly assigned Serial No. 97-70034 by that Office.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and a method for image processing, and more particularly to an apparatus and a method for image processing capable of improving a quality of an image by correcting a distortion, of an image reading sensor or a light source for analog signals proportional to quantity of light which is reflected in accordance with state of an object and obtaining a fine image by controlling a contrast and a brightness of the object and removing a background color of the object.
2. Description of the Prior Art
In general, a scanner emits light to an object and converts the light reflected by the object into an electric output value through a charge coupled device (hereinafter, referring to as CCD) and a contact image sensor (hereinafter, referring to as CIS). The output value is generally stored in a data storing device such as a harddisc of a personal computer.
The scanner which reads contents of the object such as books and pictures is made to carry out only a scanning function, or is integrated with a printer and a facsimile device.
An analog signal which is output from a CCD sensor as a photoelectric conversion device in a general color image processing device has a deviation due to an object difference between pixels of a CCD sensor as a semiconductor element. When the scanner reads an image, a quality of the image is degraded due to a distortion of a white reference plate and light emitting characteristics of a halogen lamp or a fluorescent lamp which is used as a light source.
In order to prevent the quality degradation of the image which is induced by the circuit element and parts, a black correction is carried out to correct the object difference due to an element characteristic of CCD sensor in the inputting device. Also, a white correction is carried out to remove an effect on the image due to the distortion of the white reference plate and the light source such as the fluorescent lamp or the halogen lamp.
In general, a method for correcting the distortion of the color image inputting device has three steps. That is, the method for correcting the distortion of the color image includes the steps of: reading a quantity of dark current which is output from pixels of the CCD sensor to obtain a black correcting data and then subtracting the black correcting data from the analog signals which are output from the CCD sensor in the state that a light is not input into the CCD sensor; detecting a maximum value of an image signal which is output after applying an electric power to the electric source and carrying out the black correction for the analog signal reflected by the white reference plate; and carrying out an operation for regulating the white correcting data, which is generated by detecting the distortion of the white reference plate and the light source in the range between the black reference voltage and the maximum value of the analog signal reflected by the white reference plate after applying the electric power to the light source.
The correcting the distortion of the color image inputting device will be described in detail with reference to FIG.
1
. As shown in
FIG. 1
, during output of the analog image signal, by driving a CCD sensor (not shown) in the state that the electric power is not applied to a light source (not shown) of the CCD sensor, an analog to digital converter
201
(hereinafter, referring to as A/D converter) carries out an operation to obtain the black correcting data while the analog image signal, which is output from the CCD sensor in the range between a black reference voltage V
Bref
and a black maximum voltage V
Bmax
, is converted into digital data, which in turn is stored in a memory
202
for as the black correcting data for correcting black. Memory
202
has a storage capability proportional to the number of effective pixels of the CCD sensor, in which the black correcting data are stored in an order corresponding to an output synchronous signal of the CCD sensor. Then, the electric power is applied to the light source so as to detect light reflected by a white reference plate (platen) into the CCD sensor. The black correcting data are converted into their analog value by a digital to analog converter
203
(hereinafter, referring to as D/A converter). A black correcting device
204
carries out the operation for correcting black by subtracting the analog values of the black correcting data from the analog image signal output from the CCD sensor. The black corrected analog image signal is input into an A/D converter
205
is converted into digital data in the range between a white maximum voltage V
Wmax
and the black reference voltage V
Bref
. These digital data are then input in into a detector
206
for detecting a maximum digital value, and the maximum digital valueis converted to an analog signal V
PEAK
(maximum value of pixel data of the white reference plate) by a D/A converter
207
. An A/D converter
208
converts the black corrected analog image signal into digital data in the range between the black reference value V
Bref
and the maximum value of pixel data V
PEAK
. These digital data are stored in a memory
209
as white correcting data for correcting white.
Accordingly, when the operation is carried out to read a substantial image of an object (such as a color picture or a document), the electric power is applied to the light source to input the light reflected by the object into the CCD sensor. When an image of an object is detected by the CCD sensor, black correcting device
204
carries out the operation for correcting the black of the data in response to the black correcting data transmitted from the black correcting memory
202
to the black correcting device
204
through the D/A converter
203
. White correcting device
211
carries out the operation for correcting the white of the black corrected image, output from correcting device
204
, in response to the white correcting data transmitted from the white correcting memory
209
to white correcting device
211
through D/A converter
210
. The image signal of which the distortion is corrected (black corrected and white corrected) is converted into digital image data between the black reference voltage V
Bref
which the:data, which are transmitted through the A/D converter
212
and the data bus and stored in a latch
215
, are converted into by the D/A converter
214
and the white reference voltage V
Bref
which the data, which are stored in the latch
216
through the data bus, are converted into by D/A converter
213
. Therefore, the image of the object can be read by using the digital data.
Here, in the color image inputting apparatus presently produced, an application specific integrated circuit (hereinafter, referring to as ASIC) is used as a circuit which carries out correction of the distortion.
In the image processing according to the present invention, however, since given values in a predetermined range are selectively used to control the contrast and brightness of the image by necessity, there is a problem in that when the values are better applied to the object, the control program of the image inputting apparatus is modified to reset appropriate parameters according to the condition of the object.
SUMMARY OF THE INVENTION
The present invention has been made to overcome the above described problem of the prior art.
It is an object of the present invention to provide an apparatus and a method for processing an image, in which
Bushnell , Esq. Robert E.
Lee Cheukfan
Samsung Electronics Co,. Ltd.
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