JPH04117870A - Picture information storage device - Google Patents

Abstract

PURPOSE:To store only a uniform picture data with high precision by comparing a current shading correction data sampled periodically with a succeeding data for each period and inhibiting the storage of picture information into a picture storage means when the fluctuation is a prescribed value or over. CONSTITUTION:A correction data Dn by one line resulting from reading a white reference board at a prescribed period is stored in a RAM 4a being a component of a correction data storage section 4. The data Dn in the RAM 4a is used as a shading correction data of a picture data of an original read for a prescribed period and read by a microprocessor(MPU) 10 just before a succeeding correction data Dn+1 is stored and the data Dn is compared with the succeeding correction data to discriminate the stability of the correction data. When the fluctuation exceeds a prescribed value, an original consecutive read inhibit state signal is outputted to a read control section 7 and a picture information transfer inhibit state signal is outputted to a transfer control section 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image information storage device, and particularly to a device for storing a large amount of image information in a large capacity storage medium such as an optical disk, and also for storing and reading each image information. The present invention relates to an image information storage device that facilitates accuracy.

[Prior Art] Conventionally, in an image reading device constituting an image information storage device such as Image League, there have been problems such as variations in the sensitivity of individual photoelectric conversion elements, variations in the amount of light from a light source, or differences between the central part of an optical system such as a lens, etc. In order to correct shading distortion including differences in light intensity at the periphery, the photoelectric conversion signal obtained from the reflected light of a reference plate with a uniform reflective surface such as a white board is first stored in memory as correction data in advance, and the actual When reading a document, correction data is read from the memory, and a correction calculator performs calculations to perform shading correction and obtain a reproduced image signal.

[Problems to be Solved by the Invention] However, in the conventional example as described above, when the above-mentioned image reading device is incorporated and used as an image information input means in an image scanning storage reproducing system such as an electronic file device, a large amount of When reading original documents continuously, the light intensity of the light source changes during the reading process, or the paper is placed on a white board or optical system such as a mirror or lens necessary to obtain shading correction data. When powder or dust falls,
There is a problem to be solved in that erroneous shading correction data is captured in the memory, and the image obtained based on the result is stored in the image storage device as erroneous data.

Therefore, in order to solve the above-mentioned problems, the purpose of the present invention is to provide image information that can store homogeneous and highly accurate image information that is not affected by fluctuations in the light intensity of the light source or paper powder or dust on the optical system. The purpose is to provide a storage device.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an image reading means for reading image information of a document illuminated with a light source, and a shading correction for the image information read by the image reading means. In an image information storage device having a correction means and an image information storage means for storing image information subjected to the shading correction, shading correction data obtained by reading a reference white board at a constant cycle with the image reading means is stored. a correction data storage means, a fluctuation determination means for determining whether or not a period-by-cycle fluctuation amount of the correction data stored in the correction data storage means is equal to or less than a predetermined constant value; and a negative determination by the fluctuation determination means. [Function] In the present invention, the reference white board is recorded at regular intervals. Especially the shading obtained? iii. The correct data is stored in the correction data storage means, and the fluctuation determination means determines whether the fluctuation of the data stored in the storage means is less than or equal to a predetermined constant value. When it is determined that the value exceeds a predetermined value, the control means stops storing the image information in the image information storage means, so that highly accurate image information can be stored in the image information storage device. I can do it.

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic circuit configuration of an embodiment of the present invention. In the figure, 1 is a light source for illuminating the original, 2 is a white plate (also referred to as a white reference plate) that serves as a reference for shading correction values, and 3
is a photoelectric conversion unit consisting of a mirror, lens, image sensor, and A/D converter.

A correction data storage section stores the shading correction data obtained by reading the white board 2 by the photoelectric conversion section 3; ) to determine whether the amount of variation exceeds a certain value. Fluctuation 1'! 1 separate section, 6 (J
This is a correction calculation section that performs shibbling correction on image data using the correction data stored in the correction data storage/band section 4. Reference numeral 7 denotes a reading control unit that stops the reading operation based on the result of the fluctuation determining unit 5 determining that the amount of fluctuation in the correction data exceeds a certain value.

8 is an image storage unit that stores image information; 9 is a variation determination unit 5
This is a transfer control unit that controls to stop the transfer of image information and search information to the image storage unit 8 based on the result of determining that the amount of variation in correction data exceeds a certain value.

Figure 2 shows the circuit in Figure 1 in detail, and also shows the circuit in Figure 3.
The figure shows the processing procedure of the microprocessor 10 of FIG.

Next, the operation of the image reading device will be explained with reference to FIGS. 2 and 3.

First, when reading a document, a white plate 2 having a uniform reflective surface is illuminated with a light source 1 at a certain period, and the reflected light is read by a photoelectric conversion unit 3. Both signals read by the photoelectric conversion section 3 are stored in the mass correction data storage section 4 as shading correction data. Next, the image data obtained by reading the actual document is subjected to shading correction by the correction calculation section 6 based on the shading correction data stored in the correction data storage section 4, and is stored as an image signal for reproduction. It is stored in section 8.

By the way, since the shading correction data stored in the correction data storage section 4 is fetched at regular intervals, when a document is read continuously at high speed, fluctuations in the light intensity of the light source 1, Alternatively, if the shading correction data fluctuates due to reasons such as dust such as paper dust adhering to the mirrors and lenses that make up the optical system, or the white board 2 that serves as the reference for shading correction values, the image will be stored. The image data stored in the unit 8 becomes less accurate.

Therefore, in the embodiment of the present invention, as shown in FIG.
Highly accurate data is stored by the correction data storage section 4, variation determination section 5, reading control section 7, and transfer control section 9 performing the following operations.

That is, in FIG. 2, the RAM (random access memory) 4a constituting the correction data storage section 4 includes:
Correction data Dn for one line read from the white board 2 at a certain period is stored (see step S1 in FIG. 3).

The data Dn in the RAM 4a is used as shading correction data for the image data of the document read during the above-mentioned fixed period, and the data Dn+ is used for the next correction data Dn+.
Immediately before storing the +, the micro-
The data is read out by the processor (MPU) (step S2), and the stability of the correction data is determined by comparing and calculating with the next correction data. For example, if the amount of variation in the correction data is ΔD, then ΔD can be obtained from the following equation.

ΔD=l(Dn,,-D,)l-(
1) Then, (formula 11 (accordingly, the amount of variation ΔD between this time and the next time is calculated by the microprocessor lO), step S3), and furthermore, this calculated amount of variation ΔD is less than a predetermined constant value S. Determine whether or not.

In this embodiment, this variation amount ΔD is stored in the RAI +5a constituting the variation determination section 5 (step S4), and this variation amount ΔD is compared with the constant value S of the constant setter 13 by the comparison circuit 5b. (Step S5).

If the braking determination unit 5 confirms that the stability of the correction data is good, that is, the amount of variation ΔD is below the constant value S,
The microprocessor 10 outputs a document continuous reading permission state signal to the reading control unit 7 (step S6).
, an image information transfer permission state signal to the image storage section 8 is output to the transfer control section 9 (step S7), and a correction data reading position signal as search information is written to the image storage section 8 (step S7). The configuration is as shown in step S8).

On the other hand, if the stability of the correction data is determined by the fluctuation determination unit 5,
In other words, it is confirmed that the fluctuation amount exceeds the constant value S']
E] (Step S5), a document continuous reading device stop state signal is output from the microprocessor 10 to the reading control unit 7.
(Step S9), and outputs an image information transfer prohibition state signal to the transfer control unit 9 (Step 5IO), and further outputs a search information signal to the image storage unit 8 to validate the stored image up to the time of reading the previous correction data. is output (step 511
).

In this way, according to this embodiment, the amount of variation between the current and next time in the periodically sampled shading correction data is calculated without providing any new light amount detection means,
It is possible to permit reading and storage only when each pixel falls below a certain value; otherwise, reading is prohibited and the stored image information up to the time of the previous correction data reading is made valid. Therefore, homogeneous and highly accurate image information can be obtained even when a large number of originals are continuously read and stored.

Other Embodiments In the embodiment of the present invention described above, the shading correction data obtained by reading the white board is simply compared between the previous and current shading correction data for all pixels, and if the amount of variation in the correction data is less than a certain value, 1'] 1 to determine whether or not there is one, but of course, D to the peak value and I to the lowest value of the Judein correction data.
A similar effect can be obtained by detecting ⇠, calculating the following formula (2), and comparing the calculation result ΔD' with a certain constant value δ.

In addition, the shading correction data obtained by reading the white board is integrated for all pixels, and the amount of change between pixels that compares with tJ is calculated.・A similar effect can be obtained by creating a Duram, calculating the previous and current fluctuations in that Histo Duram, and comparing it with a certain constant value ψ.

[Effects of the Invention] As explained above, according to the present invention, the shading correction data sampled periodically is compared with the current data and the next data, and the amount of variation is set to a certain constant value. In the above cases, storage of image information in the image storage means is prohibited, so the image information stored in the image storage means is free from fluctuations in light intensity and the influence of dust on correction data. First, it is possible to store only homogeneous and highly accurate image data.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a schematic circuit configuration of an embodiment of the present invention, Fig. 2 is a block diagram showing the circuit in Fig. 1 in more detail, and Fig. 3 is a processing procedure of the microprocessor shown in Fig. 2. It is a flowchart which shows. DESCRIPTION OF SYMBOLS 1... Light source, 2... White board, 3... Photoelectric conversion section, 4... Correction data storage section, 5... Fluctuation discrimination section, 6... Correction calculation section, 7... Reading Control unit, 8... Image storage unit, 9... Transfer control unit, 10... Microprocessor, 1.1. -RAM-5a. J2...Data comparison section, ]3...Constant setter.

Claims (1)

[Scope of Claims] 1) Image reading means for reading image information of a document illuminated by a light source, correction means for applying shading correction to the image information read by the image reading means, and image information subjected to the shading correction. An image information storage device comprising: an image information storage means for storing shading correction data obtained by reading a reference white board at regular intervals with the image reading means; a fluctuation determining means for determining whether or not a periodic fluctuation amount of the stored correction data is equal to or less than a predetermined constant value; and image information to the image information storage means in response to a negative determination by the fluctuation determining means. 1. An image information storage device comprising: a control means for stopping storage processing of the image information storage device.