JP2001007987A - Image processing method, image reader and its adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify position adjustment in the case of assembling and adjusting a scanner by adjusting a position of a visible light sensor and an invisible light sensor on the basis of a reference chart. SOLUTION: The adjustment result of focus of R, G, B sensors is observed by a G output so that the contrast of lines of a reference chart is maximized. Skew of the R, G, B sensors is adjusted by matching the parallelism of the sensors with respect to the reference chart. Furthermore, the skew of an infrared ray(IR) sensor is adjusted similarly to the case with the focus adjustment of the R, G, B sensors. After finishing the focus adjustment and the skew adjustment, the reference chart is scanned to convert coordinates and to obtain correction parameters (m, x0, y0) for image processing. Through the adjustment above, the registration (position adjustment) of the R, G, B sensors and the IR sensor can accurately be adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing method, an image reading apparatus to which the method is applied, and a method of adjusting the same. More specifically, the present invention has a function of reading a film with invisible light such as infrared light. In a film reading apparatus, a film image processing method suitable for easily performing registration between a sensor for visible light and a sensor for invisible light, a film image reading apparatus to which the method is applied, and a method of adjusting the apparatus It is about.

[0002]

2. Description of the Related Art Conventionally, printing an image photographed on a photographic film (hereinafter, also simply referred to as a film) such as a negative film or a positive film (reversal film) onto a photographic paper is performed by projecting the image of the film onto the photographic paper. What is called direct exposure (analog exposure), which exposes photographic paper to the surface, has been the mainstream, but in recent years, printing apparatuses that use digital exposure,
That is, the image of the film is photoelectrically read, the read image is converted into a digital signal, and then subjected to various image processing to obtain image data for recording, and the photographic paper is scanned with recording light modulated according to the image data. 2. Description of the Related Art Digital printers that record images by exposure have been put to practical use.

In a digital printer, an image is converted into digital image data, and the exposure conditions at the time of printing are determined by image data processing. It is possible to obtain a high-quality print which could not be obtained by the conventional direct exposure by suitably performing (sharpening) processing, correcting color or density feria, and the like. Also, synthesis of a plurality of images, image division, and synthesis of characters can be performed by image data processing, and a print that has been freely edited / processed according to the intended use can be output.

[0004] Such a digital printer basically includes a scanner (image reading device) for photoelectrically reading an image recorded on a film, and image data for output by processing the image read by the scanner. An image input device having an image processing device that sets exposure conditions), a printer that scans and exposes photographic paper according to image data output from the image input device to record an image (latent image), and And an image output device having a processor that performs development processing on photographic paper to produce a print.

In the above-described scanner, reading light emitted from a light source is made incident on a film to obtain projection light carrying an image on the film, and this projection light is converted into a C light by an imaging lens.
An image is read by forming an image on an image sensor such as a CD sensor and photoelectrically converting the image, performing various types of image processing as necessary, and then sending the image data (signal) of the film to an image processing apparatus. The image processing apparatus sets image processing conditions from image data read by the scanner,
The image processing is performed according to the set conditions, and is sent to the printer as output image data for image recording.

In a printer, for example, if the apparatus uses light beam scanning exposure, the light beam is modulated in accordance with image data sent from an image processing apparatus, and the light beam is deflected in the main scanning direction. By transporting the printing paper in a sub-scanning direction orthogonal to the main scanning direction, the printing paper is exposed (printed) by a light beam carrying an image to form a latent image, and the latent image is developed by a processor. To produce a print that reproduces the image on the film.

By the way, in order to obtain a high-quality print in which a high-quality image is reproduced, it is essential that a film serving as an original image of the print is in a good condition. This film is transported in a camera, scanner, or the like for photographing, developing, reading (printing), and the like. At this time, the film surface comes into sliding contact with a support member or the like, and as a result, the film surface It may be scratched. Further, since the film is often handled in an ordinary environment in which air is not particularly cleaned, it is not rare that foreign matters such as dust and dirt adhere to the front and back surfaces.

As described above, the reading of a film image by a scanner is performed by irradiating the film with reading light to obtain projection light, and photoelectrically reading the projection light with a CCD sensor or the like. At this time, if a foreign substance adheres to the film surface or the film surface is damaged, the reading light (projection light) is blocked or diffused to reduce the light amount. As a result, the transmitted light amount of the reading light increases, and the light intensity of the projection light incident on the CCD sensor or the like is not appropriate for the image photographed on the film.

As a result, a high quality image can be obtained by reproducing foreign matter or a scratch in the obtained image as a shadow, or blurring the image around the scratch. I can no longer do it. For such issues,
Various countermeasures have been proposed. For example, registered patent No. 2
559970.

The above technique is directed to a method or an apparatus for correcting the effect of a film defect on an image stored in a storage medium (film), wherein the film is exposed to infrared energy and visible light energy, and the resulting defect is removed. The corresponding infrared energy distribution is detected in association with the position on the film, while the visible light energy distribution is detected in association with the position on the film, and for each position on the film, the detected infrared energy distribution intensity is detected. Is greater than a predetermined threshold, the visible light energy distribution intensity at the position is increased to a level that cancels out the infrared energy distribution intensity at the position, and if the detected infrared energy distribution intensity is equal to or less than the predetermined threshold, the visible light energy at the position is reduced. By correcting the light energy distribution intensity by interpolation, the film Is that to correct the influence of the defect.

[0011]

In a digital printer, a film scanner used for reading a film (hereinafter simply referred to as a scanner).
Has a visible light sensor for detecting visible light as described above and a non-visible light sensor for detecting invisible light (normally, infrared light). Since the refractive index differs depending on the wavelength, registration (position adjustment) of these two (two types) sensors at the time of assembling the above-described scanner requires a great deal of labor and time.

Hereinafter, this will be described in detail. For example, when a three-line sensor for detecting visible light (R, G, B) and a one-line sensor for detecting non-visible light (here, infrared, hereinafter referred to as IR) are incorporated in the scanner, each detection light is used. It is necessary to accurately position each sensor at a focus position corresponding to the wavelength of the light. Conventionally, this operation has been performed almost manually. For example, in a method using a dichroic prism, first, assembling adjustment of a three-line sensor for detecting visible light is performed.

This operation consists of adjusting the focus so that the entire line is in focus, and adjusting the optical axis so that there is no skew. Next, the assembly adjustment of the IR detection one-line sensor is performed in the same manner as above. Further, the position adjustment between the two sensors described above is performed. In this adjustment, the focus position is not adjusted between visible light and IR due to the problem of chromatic aberration of the projection lens. It is very difficult to eliminate the RGB wavelength and the chromatic aberration at the wavelength of the IR detection sensor, and even if it can be done, it becomes a very expensive lens.

The present invention has been made to solve the above-mentioned problem in the prior art, that is, the problem that both focus and magnification cannot be adjusted with visible light and IR. Typically, visible light and IR
It is an object of the present invention to simplify the position adjustment (registration) at the time of assembling adjustment of the scanner by correcting the difference between the image read by the visible light and the image read by the IR in the film reading by the above method. An object of the present invention is to provide an effective image processing method, an image reading apparatus to which the method is applied, and a method for adjusting the apparatus.

[0015]

In order to achieve the above object, an image processing method according to the present invention reads image information on a film using a sensor for visible light, and reads image information on the film using a sensor for invisible light. An image processing method for reading information related to dust and scratches on the film, detecting dust and scratches on the film, and correcting image information by the visible light sensor based on the detected information. The position adjustment between the sensor and the invisible light sensor is performed based on a reference chart.

In the image processing method according to the present invention, the position adjustment between the visible light sensor and the invisible light sensor is performed by a correction parameter relating to at least one of magnification correction and line position correction of the reference chart. I do. Further, in the image processing method according to the present invention, it is preferable that the magnification correction is correction of chromatic aberration of magnification of a projection lens, and that the invisible light is an infrared ray.

Further, the image reading apparatus according to the present invention comprises:
The image information on the film is read using the sensor for visible light, the information related to dust and scratches on the film is read using the sensor for invisible light, and the dust and scratches on the film are detected. A film image reader having a visible light sensor and an invisible light sensor, wherein the image information is corrected by image processing based on the visible light sensor based on the obtained information. It is characterized by including a position adjusting means for performing based on the chart.

In the image reading apparatus according to the present invention,
The position adjustment between the sensors by the position adjusting means is performed by:
It is based on a correction parameter relating to at least one of magnification correction and line position correction of the reference chart. Further, the magnification correction is correction of chromatic aberration of magnification of the projection lens. Still further, the non-visible light is infrared light.

In the method of adjusting an image reading apparatus according to the present invention, image information on a film is read using a sensor for visible light, and information relating to dust and scratches on the film is read using a sensor for invisible light. And a sensor for visible light and a sensor for non-visible light for detecting dust and scratches on the film, and correcting image information by the sensor for visible light by image processing based on the detected information. When adjusting the film image reading device, a position adjustment between the sensors is performed using a correction parameter between the reference chart images read by the sensors.

In the adjusting method of the image reading apparatus according to the present invention, the correction parameters between the images are based on correction parameters relating to at least one of magnification correction and line position correction of the reference chart. Further, the magnification correction is correction of chromatic aberration of magnification of the projection lens. Still further, the non-visible light is infrared light.

[0021]

According to the present invention, when adjusting the positions of the visible light sensor and the invisible light sensor, a reference chart is read between two or more images obtained by focusing on each of the sensors. By performing the position adjustment using the correction parameters described above, the position adjustment (registration) at the time of assembling and adjusting the scanner can be simplified.

Further, for example, by storing correction parameters between two or more images obtained by focusing a reference chart on each of the sensors and reading them, the values are stored as unique values of the respective scanners. It is also possible to readjust the device at the point in time after the installation, using the value set at the time of adjustment).

[0023]

Embodiments of the present invention will be described below in detail with reference to preferred embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing an outline of a photographic processing apparatus including a film image reading apparatus (film scanner) according to one embodiment of the present invention. A photographic processing apparatus 10 shown in FIG. 1 includes a film scanner 11 that photoelectrically reads a film document, an image processing unit 12 that performs necessary image processing on an image read by the film scanner 11, and a processing unit that processes the image. Printer 21 that scans and exposes photographic paper (photosensitive material) in accordance with the obtained image data (exposure conditions)
And an image output device 13 comprising a processor 22 for developing the exposed photographic paper. Note that the image processing unit 12 is connected to a CRT monitor 12a for verification and a keyboard 12b.

FIG. 2 shows the above-described film scanner (hereinafter, referred to as a film scanner).
11 shows a detailed configuration example of a scanner 11. FIG.
Reference numeral 111 denotes a light source lamp, 112 denotes an aperture, 113 denotes a mirror box, 114 denotes a diffusion plate, 115 denotes a film to be read, 116 denotes an imaging lens, 117 denotes a dichroic prism, 118 denotes an RGB 3-line CCD, and 119 denotes IR (infrared rays). 1) shows a one-line CCD. Also,
120a denotes an amplifier, and 120b denotes an A / D (analog / digital) converter.

As shown in FIG. 2, an RGB three-line CCD
From 118, RGB image information is read and sent to the next stage (image processing unit 12) as digital data.
Further, dust / flaw information detected by infrared rays is sent from the one-line IR CCD 119 to the next stage (image processing unit 12). Although not shown, the scanner 1
1 generally shows the type of film to be processed (negative film / positive film, with / without magnetic layer, color /
Detection means for reading monochrome or the like, or instruction means for instructing the type of film.

FIG. 3 shows R, R in the scanner 11 described above.
The mounting (incorporation) adjustment operation of the G, B, and IR sensors is shown. In FIG. 3, reference numerals 121 to 125 denote steps for explaining the operation, reference numeral 121 denotes focus adjustment of the R, G, B sensors, reference numeral 122 denotes skew adjustment of the R, G, B sensors, and reference numeral 123 denotes the focus of the IR sensor. Adjustment, 124 is IR
The skew adjustment of the sensor and the calculation of the instrument difference parameter 125 are shown, respectively.

FIG. 4 shows an actual dust / scratch detection processing operation after completion of the above-described installation adjustment operation of the scanner 11. In FIG. 4, reference numerals 131 to 135 denote steps for explaining the operation. Reference numeral 131 denotes a readout of the parameters calculated above, 132 denotes a coordinate conversion process of IR image data using these parameters, and 133 denotes a coordinate conversion process. Dust / scratch detection processing using the IR image data obtained, 134 denotes detection processing of the detected dust / scratch, and 135 denotes enlargement / reduction and other various image processing.

Hereinafter, the above-described built-in adjustment operation and dust,
The details of the flaw detection processing operation will be described. First, the adjustment operation for mounting the sensor will be described with reference to FIG. Step 1
At 21, the focus adjustment of the R, G, and B sensors is viewed with the G output so that the contrast of the line of the reference chart (hereinafter referred to as the reference chart) as shown in FIG. 5 is maximized. At this time, look at the contrast of the entire screen,
It is necessary to make sure that there is no one-sided blur and the entire line is in focus.

In step 122, the skew of the R, G, and B sensors is adjusted by adjusting the parallelism of the sensor to the reference chart. In step 123, IR adjustment is performed similarly to the focus adjustment of the R, G, and B sensors.
Adjust the focus of the sensor. In step 124, R,
The skew adjustment of the IR sensor is performed in the same manner as the skew adjustment of the G and B sensors.

After the focus adjustment and the skew adjustment are completed,
In step 125, by scanning the reference _{chart, x 'IR = m · x} IR + x 0 y' IR = m · y IR + y 0 ( where, x _IR, y _IR before coordinate transformation, x _'IR, y ′ _IR performs coordinate conversion of the converted coordinates, and obtains correction parameters (m, x ₀ , y ₀ ) in image processing. This correction parameter is stored in the apparatus as a machine difference parameter. FIG.
FIG. 7 shows an example of a reference chart reading result using G light (broken line) and IR light (solid line).

With the above adjustment operation, the registration (position adjustment) of the R, G, B sensors and the IR sensor can be performed accurately. In the above embodiment, the correction equation is exemplified as a linear equation. However, if the chromatic aberration of magnification of the lens is expressed by a cubic equation, the correction accuracy can be improved. y ′ _IR = m ₃ · y ³ _IR + m ₂ · y ² _IR + m ₁ · y _IR + y
₀ (Here, the y direction is the direction in which the CCD extends, that is, the main scanning direction) On the other hand, in the x direction, the effect of the chromatic aberration of the lens can be almost neglected, and the linear expression is sufficient. Hereinafter, the operation of the photo processing apparatus 10 according to the present embodiment using the scanner adjusted as described above will be described with reference to FIG.

When a film to be processed is set on the scanner 11, the scanner 11 first detects the type of the film. Here, it is assumed that the film is recognized as a 135 size (no magnetic layer, not APS), color negative film.

Next, the scanner 11 reads out the correction parameters measured and stored in advance (FIG. 4, step 131). Then, using this parameter, a coordinate conversion process of the read IR image data is performed (step 132). Next, dust and flaw detection processing is performed based on the coordinate-converted IR image data (step 13
3). In step 134, correction processing of the dust and flaw detected above is performed. Further, in step 135, enlargement,
It performs reduction and other various image processing.

As a result, as shown in FIG.
Image data of three colors (hereinafter referred to as RGB image information) and a result of detection of flaws and dust by IR light (hereinafter referred to as dust flaw information) are obtained. These data are sent to the image processing unit 12 at the next stage.

The image processing section 12 displays, on the CRT monitor 12a, the result of detection of flaws and dust by the above-mentioned IR light (dust flaw information) among the above-mentioned data sent from the scanner 11, and analyzes the result. . This analysis is performed, for example, by comparing predetermined thresholds of various characteristic values with characteristic values obtained from the above-described data sent from the scanner 11.
The user may be asked to judge the presence or absence of dust / scratch.

As a result of the above analysis, if the IR pre-scan image sent from the scanner 11 shows an abnormality considered to be caused by the presence of dust or scratches in the optical path in the scanner 11, for example, Take measures to make dust and scratches less noticeable, such as changing the position of the diffusion plate.

In the case where no abnormality considered to be caused by the presence of dust or scratches in the optical path in the scanner 11 is found, a fine scan of R, G, B and IR is carried out. Based on the obtained image data, for example, processing such as dust damage correction and various image processing is performed.

In the IR reading, if the focus position is shifted (shifted) on the diffusion plate instead of the normal film surface, the contrast of dust / scratch increases, and the dust / scratch can be easily detected. Is obtained. In other words, if the focus is on the film surface, the dust and scratches on the diffuser plate will be reduced in contrast, so this will be relieved.

The above embodiment is merely an example of the present invention, and it goes without saying that the present invention is not limited to this. For example, the film to be read may be of any type such as a negative film / positive film and a magnetic layer. However, in the case of a monochrome film, since silver constituting an image has IR absorption, dust and scratches in the optical path cannot be detected when the monochrome film is present in the optical path of the scanner.

[0041]

As described above in detail, according to the present invention, in the film reading by the visible light and the IR, the difference between the image read by the visible light and the IR is corrected to adjust the assembly of the scanner. It is possible to realize an image processing method capable of simplifying position adjustment (registration) at the time, an image reading apparatus to which the method is applied, and an adjustment method of the apparatus.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an outline of a photo processing apparatus including a scanner according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration example of a film scanner 11 in the photographic processing apparatus shown in FIG.

FIG. 3 illustrates R, G, and R in the scanner 11 illustrated in FIG. 2;
It is a figure explaining attachment (incorporation) adjustment operation of B sensor and IR sensor.

FIG. 4 is a diagram illustrating dust / scratch detection processing operation.

FIG. 5 is a diagram showing an example of a reference chart.

FIG. 6 is a diagram illustrating an example of a reference chart reading result using G light (broken line) and IR light (solid line).

[Explanation of symbols]

 Reference Signs List 10 photo processing device 11 film scanner 111 light source lamp 112 aperture 113 mirror box 114 diffuser 115 film to be read 116 imaging lens 117 dichroic prism 118 RGB 3-line CCD 119 IR 1-line CCD 120a amplifier 120b A / D converter 12 image processing Part 13 Image output device

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) XA04

Claims (11)

[Claims] The image recording medium is read by using a visible light sensor to read image information on the image recording medium, and using an invisible light sensor to read information related to dust and scratches on the image recording medium. An image processing method for detecting dust and scratches on the top and correcting image information by the visible light sensor based on the detected information, wherein the position adjustment between the visible light sensor and the invisible light sensor is performed. An image processing method based on a reference chart. 2. The image processing method according to claim 1, wherein the position adjustment between the visible light sensor and the invisible light sensor is performed by a correction parameter relating to at least one of magnification correction and line position correction of the reference chart. 3. The image processing method according to claim 1, wherein the magnification correction is chromatic aberration correction of a projection lens. 4. The invisible light is infrared light.
4. The image processing method according to any one of 3. 5. An image recording medium which reads image information on an image recording medium using a visible light sensor and reads information related to dust and scratches on the image recording medium using an invisible light sensor. An image reading apparatus comprising: a visible light sensor and a non-visible light sensor for detecting dust and scratches on the upper side, and correcting image information by the visible light sensor by image processing based on the detected information. An image reading apparatus comprising: a position adjusting unit that performs position adjustment between the sensors based on a reference chart. 6. The image reading apparatus according to claim 5, wherein the position adjustment between the sensors by the position adjustment means is performed by a correction parameter relating to at least one of magnification correction and line position correction of the reference chart. 7. The image reading apparatus according to claim 6, wherein the magnification correction is chromatic aberration of magnification of a projection lens. 8. The invisible light is infrared light.
8. The image reading device according to any one of items 7 to 7. 9. The image recording medium which reads image information on the image recording medium using a visible light sensor and reads information related to dust and scratches on the image recording medium using a non-visible light sensor. Adjust an image reading device having a visible light sensor and an invisible light sensor, which detects dust and scratches above and corrects image information by the visible light sensor by image processing based on the detected information. In this case, a position adjustment between the sensors is performed using a correction parameter between the reference chart images read by the sensors. 10. The method according to claim 9, wherein the correction parameter between the images is a correction parameter relating to at least one of magnification correction and line position correction of the reference chart. 11. The method according to claim 10, wherein the magnification correction is chromatic aberration correction of a projection lens.