JP2005269353A - Image reader and image reading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader capable of detecting dust attached onto a transparent original and flaw of the transparent original with detection accuracy that is desired by a user. <P>SOLUTION: Detection accuracy for detecting dust and flaw information of the transparent original is set (Step 2), a visible light image of the transparent original is read (Step 3), the dust and flaw information of the transparent original is detected on the basis of the detection accuracy set in the step 2 (Step 5), and the visible light image read in the Step 3 is corrected by using the dust and flaw information detected in the Step 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that reads a transparent original, and more particularly to correction of dust and scratches.

  In recent years, with the development of communication networks, faster computers, and larger storage media, higher image quality has been desired for handling color image information. There is an increasing demand for more accurate and high-speed reading of image information.

  In addition, the demand for image reading of photographic film is also increasing. The demand for reading photographic film image information in a sleeve form having a plurality of frames more accurately, at high speed and with high image quality is increasing.

  As a means for reading dust / scratches on a photographic film as means for reading a photographic film with higher image quality, Patent Document 1 shown below can be cited. According to the proposal, it is configured as a surface light source having an infrared LED for detecting dust / scratch information and a light source for reading image information, and can read an image from which dust / scratch information has been removed. It has become.

  FIG. 3 is a cross-sectional view showing an example of an image reading apparatus having a dust / scratch correcting function and capable of reading a document original (reflective original) and a photographic film (transparent original).

  The image reading apparatus 1 is provided with a transmissive original illumination device 2 necessary for reading the photographic film 20 and is transmissive original light source lighting inverter 4 and an I / F cable so as to be controllable from the image reading apparatus control board 3. 5 is electrically connected. This figure shows that a transparent original light source 6 for irradiating a read transparent original with visible light and infrared light is provided.

  Further, the first reflection mirror 8, the second reflection mirror 9, the third reflection mirror 10, the fourth reflection mirror 11, and the fifth reflection mirror, which are necessary for optically forming an image of the document to be read on the CCD image sensor 7. The optical unit 15 including the reflecting mirror 12, the lens 13, the optical path length correction glass 21 for visible light, and the reflection source illumination light source 14 for irradiating a document document or the like as an integral moving member includes the image reading device control board 3 and the optical unit 15. A motor 17 electrically connected by a signal cable 16 reads the image while scanning in the direction of the arrow.

  Further, the optical path length correction glass 21 for visible light can be removed from or inserted into the optical path by being tilted or raised. The CCD image sensor 7 and the image reading device control board 3 are electrically connected by a signal cable 18. The image reading control board 3 is connected to an external interface 19. The image reading apparatus control board 3 is externally controlled via the external interface 19, and an electrical signal photoelectrically converted by the CCD image sensor 7 is used as image data. Output to the outside.

  In order to detect dust / scratch information of the film original 20, infrared light is irradiated from the light source 6 for transparent original, the optical path length correction glass 21 for visible light is tilted, and the infrared light is focused on the surface of the film original. Adjust the optical path length as follows. In this state, by controlling the optical unit 15 using the image reading device control board 3, image data obtained by irradiating infrared light and scanning a film document can be obtained.

  FIG. 4 is a block diagram illustrating a functional configuration of a dust / scratch removal unit 22 that performs dust / scratch correction on image data output from the image reading unit 21 in the image reading device 1, and is configured by a computer. The operation unit 29 is operated by the user.

  The image data read from the image reading unit 21 with visible light from the light source 6 for the transparent document passes through the interface 23 and is stored in the image memory 24 for the transparent document. The image data read from the image reading unit 21 with the infrared light of the light source 6 for the transmissive document passes through the interface 23 and is accumulated in the dust / scratch detection image memory 25.

The dust / scratch information detection unit 26 detects dust / scratch information from the image data stored in the image memory 25 on the basis of parameters for correcting dust / scratches selected in advance by the user. Image data stored in the image memory 24 based on the detected dust / scratch information based on the dust / scratch correction parameters selected by the user in advance by the dust / scratch correction processing unit 28. Apply correction to.
JP 2002-281250 A

  In the above-described conventional example, it is possible to specify a parameter for correcting dust / scratches, but it is not possible to specify the accuracy for detecting dust / scratch information.

  For this reason, it is not possible to perform dust / scratch correction at high speed even if the accuracy of dust / scratch information is sacrificed, or to perform dust / scratch correction from high-precision dust / scratch information even if speed is sacrificed. Therefore, it was necessary to always process the garbage / scratch information with uniform accuracy.

  The present invention has been made under such circumstances, and an object of the present invention is to provide an image reading apparatus capable of detecting dust / scratches in a transparent document with detection accuracy desired by a user. .

  In order to solve the above problems, in the present invention, the image reading apparatus is configured as described in (1) below, and the image reading method is configured as described in (2) below.

(1) image reading means for reading a visible image of a transparent original;
Detecting means for detecting dust / scratch information of the transparent original;
Setting means for setting the detection accuracy of the detection means;
Correction means for correcting the visible image read by the image reading means using dust / scratch information detected by the detection means;
An image reading apparatus comprising:

(2) Step A for setting detection accuracy for detecting dust / scratch information of a transparent document;
Step B for reading the visible image of the transparent original;
Step C for detecting dust / scratch information of the transparent original based on the detection accuracy set in Step A;
Step D for correcting the visible image read in Step B using the dust / scratch information detected in Step C;
An image reading method comprising:

  According to the present invention, dust / scratches placed on a transparent original can be detected with detection accuracy desired by the user.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to an embodiment of an image reading apparatus. The present invention is not limited to the form of the apparatus, and can be implemented in the form of a method supported by the description of the embodiments.

  The “image reading apparatus” according to the first embodiment will be described. Since the hardware configuration and functions of the image reading apparatus of this embodiment are the same as those of the conventional example, FIGS.

  Hereinafter, the transparent original reading operation of the image reading apparatus will be described with reference to the flowchart of FIG.

  In step 1, the reading resolution of the visible image required by the user is input from the button 31 on the operation unit 29 in FIG. The resolution of the read image from the user is input to the image reading apparatus 1 by the operation unit 29. If there is no input from the user, the default resolution or the resolution set by the previous input is displayed on the button 31 and the user confirms.

  In step 2, the detection accuracy of dust / scratch information required by the user is input from the button 32 of the operation unit 29 in FIG. The operation unit 29 inputs the detection accuracy of dust / scratch information from the user to the image reading apparatus 1.

  In this embodiment, three types of “high speed, standard, high accuracy” are prepared as detection accuracy of dust / scratch information. When “High Speed” is selected, the detection accuracy of dust / scratch information is low, but the dust / scratch detection image can be read at high speed. When “high accuracy” is selected, the dust / scratch information detection accuracy is high, but the dust / scratch detection image reading speed is slow. In the case of “standard”, the accuracy and reading speed are intermediate between the two.

  Further, when the maximum resolution that can be read by the image reading device 1 is specified in step 1, the dust / scratch detection image cannot be set higher than the resolution, so that “high accuracy” cannot be selected by the user. If the minimum resolution that can be read by the image reading apparatus 1 is specified, the dust / scratch detection image cannot be set to a resolution lower than the resolution, so that “high speed” cannot be selected by the user. .

  In step 3, a visible image is read at the resolution set in step 1.

  In step 4, the resolution for reading the dust / scratch detected image is determined from the accuracy set in step 2. For example, when the reading resolution of the visible image is 1200 dpi, 600 dpi is specified when “high speed” is specified, 1200 dpi when “standard” is specified, and 2400 dpi when “high accuracy” is specified. The resolution for reading the dust / scratch detected image is determined.

In step 5, the dust / scratch detection image is read with the determined resolution.
In other words, infrared light for dust / scratch detection is applied to the transmitted original, and the irradiated light beam is transmitted regardless of the density of the image of the transparent original such as negative, positive, etc. And the like are projected as a ridge on the CCD 7. The infrared light image projected on the CCD 7 is converted into an electrical signal and temporarily stored in the dust / scratch detection image memory 25.

In step 6, dust / scratch information is detected from the dust / scratch detection image.
In other words, the gradation level of the dust portion is naturally low regardless of the image density of the transparent original. Infrared light passes through the part other than dust, and the level is almost constant. Therefore, the dust / scratch information detection unit 26 sets a threshold value at a gradation level lower than this level, and detects a defect area information due to dust / scratches by extracting a portion below the threshold value.

  In step 7, the dust / scratch information conversion unit 27 converts the information detected in step 6 so that it can be applied to the visible image. For example, when the resolution for reading a visible image is 1200 dpi, when a dust / scratch detection image is read at 600 dpi, the dust / scratch information cannot be used as it is because it is 600 dpi information. Therefore, conversion is performed so that the image of dust / scratch information can be applied to an image of 1200 dpi by enlarging the image twice.

In step 8, image correction is performed based on the read visible image and the converted dust / scratch information.
That is, the dust / scratch correction processing unit 28 identifies a defect region due to dust / scratch in the visible image by the defect region detected by infrared light, and performs interpolation processing of the defect region of the visible image from the surrounding normal region. To reduce the effects of dust.

  As described above, according to the present embodiment, dust / scratch detection can be performed with detection accuracy desired by the user by setting the dust / scratch information detection accuracy as required by the user.

(Modification of Example)
According to the present invention, a storage medium or a recording medium on which software program codes for realizing the functions of the above-described embodiments are recorded is attached to a system or apparatus, and the computer of the system or apparatus (including a processing arithmetic unit) includes It is also achieved by reading out and executing the program code of the software recorded on the storage medium or the recording medium. In this case, the storage medium or the software program code read from the storage medium realizes the functions of the above-described embodiments.

  In addition, by executing the program code of the software read by the computer of the system or apparatus, not only the functions of the above-described embodiments are realized, but also the computer is operated on the computer based on the contents of the program code of the software. The operation system is responsible for part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

  After the program code of the software read from the storage medium or the recording medium is transferred to the storage medium or the recording medium provided in the hardware for extending the function associated with the computer of the system or apparatus, the software Based on the contents of the program code, the processing arithmetic unit provided in the hardware for expanding the functions associated with the system or the computer of the apparatus is responsible for part or all of the actual processing, and the processing is described above. The function of the embodiment is realized.

Flowchart showing the operation of the first embodiment. The figure which shows the example of a display of an operation part Schematic sectional view showing the configuration of a conventional example Block diagram showing the configuration of a conventional dust / scratch removal unit

Explanation of symbols

31 button 32 button

Claims (5)

Image reading means for reading a visible image of a transparent original;
Detecting means for detecting dust / scratch information of the transparent original;
Setting means for setting the detection accuracy of the detection means;
Correction means for correcting the visible image read by the image reading means using dust / scratch information detected by the detection means;
An image reading apparatus comprising: The image reading apparatus according to claim 1,
An image reading apparatus, wherein the image reading resolution at the time of dust / scratch detection is changed according to a setting parameter of detection accuracy set by the setting means. The image reading apparatus according to claim 1 or 2,
An image reading apparatus that converts the image resolution of dust / scratch information detected by the detection unit in accordance with the reading resolution of a visible image when the correction unit corrects the image. Step A for setting detection accuracy for detecting dust / scratch information of a transparent document;
Step B for reading the visible image of the transparent original;
Step C for detecting dust / scratch information of the transparent original based on the detection accuracy set in Step A;
Step D for correcting the visible image read in Step B using the dust / scratch information detected in Step C;
An image reading method comprising:   A program for realizing the image reading method according to claim 4.

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