JP2001223861A - Image reader and image reading method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader and an read method for appropriately obtaining an image signal even if the spectroscopic intensity distribution of reading emitted from a light source fluctuates in the image reader and the image read method for emitting read light from the light source, including image information and photoelectrically reading light. SOLUTION: In the image reader and the image read method, fluctuation quantity information of the spectroscopic intensity distribution of reading light emitted from a light source is obtained, adjusting information for adjusting an image signal with the fluctuation of spectroscopic intensity distribution is obtained by using fluctuation quantity information, and the image signal is adjusted based on obtained adjusting information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus and an image reading method in which an image is carried on a reading light, that is, image information is included, and an image signal is obtained by photoelectrically reading the reading light. An image reading apparatus that obtains an appropriate image signal in consideration of a variation in the spectral intensity distribution of a reading light, and in particular, a scanner that can obtain an appropriate image signal by using a light emitting element or a light emitting diode as a light source of the reading light Belongs to the technical field.

[0002]

2. Description of the Related Art At present, an image photographed on a photographic film (hereinafter referred to as a film) such as a negative film or a reversal film is printed on a photosensitive material (photographic paper) by projecting an image of the film onto the photosensitive material. This is performed by so-called direct exposure (analog exposure) that exposes a material surface.

On the other hand, in recent years, printing apparatuses utilizing digital exposure, that is, optically reading an image photographed on a film, converting the read image into a digital signal, and performing various image processings thereon to perform recording. 2. Description of the Related Art Digital photo printers have been put to practical use in which a photosensitive material is scanned and exposed by recording light modulated according to the output image data to record an image (latent image) and print (finished). This digital photo printer basically includes a scanner (image reading device) for photoelectrically reading an image recorded on a film, and image processing for processing the read image to output image data (exposure conditions). Input device having a device, a printer (image recording device) that scans and exposes a photosensitive material according to image data output from the image input device to record a latent image, and performs development processing on the exposed photosensitive material. And an image output device having a processor (developing device) for printing.

A scanner is provided with a light source, a light source aperture, a filter turret plate, a diffusion box, a carrier, and an imaging lens unit. The scanner emits light from a light source, for example, a halogen lamp, and the amount of light is reduced by the light source aperture. The reading light, which is filtered so as to have a specific spectral wavelength and is diffused by the diffusion box, is incident on a film supported by a carrier to obtain projection light carrying an image photographed on the film. Is imaged by an imaging lens unit on an image sensor such as a CCD sensor and photoelectrically converted to read an image. After performing various image processing as needed, the image processing is performed as film image data (image signal). Send to device.

The image processing apparatus sets image processing conditions from image data read by a scanner, performs image processing according to the set conditions on the image data, and outputs image data (exposure conditions) for image recording. And send it to the printer. 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 the image processing apparatus, and the light beam is deflected in the main scanning direction and the main scanning direction. The photosensitive material is conveyed in a sub-scanning direction perpendicular to the direction, so that the photosensitive material is exposed (burned) by a light beam carrying an image to form a latent image, and then processed in a processor in accordance with the photosensitive material. To obtain a print (photograph) in which the image photographed on the film is reproduced.

In such a digital photo printer,
Since the exposure conditions at the time of printing can be determined by image data processing using the image as digital image data,
In addition to correcting image skipping and blurring due to backlighting, strobe photography, etc., graininess suppression processing and sharpness enhancement (sharpening) for suppressing noticeable roughness (graininess) in areas with low image density due to photosensitive materials By suitably performing processing and the like, a high-quality print that cannot be obtained by conventional direct exposure can be obtained.

However, since the light source of the scanner of the digital photo printer uses, for example, a halogen lamp, the life of the light source is short, and the accumulated light emission time is about 500 hours. In addition, the amount of heat generated by light emission is large, and the temperature rises as the number of times of light emission increases, and the entire scanner becomes hotter, which shortens the life of other components and causes distortion due to thermal expansion. In addition, the light source of the scanner is liable to cause the lamp to be easily cut off even by external vibration, and must be handled with care. Further, there is a problem that the power supply of the light source is relatively large, which hinders downsizing of the scanner.

Therefore, a light emitting diode (LED), which has an overwhelmingly long life as compared with a light source such as a halogen lamp, is resistant to external vibrations, and can cope with downsizing of the scanner, is used as the light source of the scanner. Can be considered. LE
When D is used as the light source of the scanner, the light emitted by the LED has a single mountain-shaped spectral intensity distribution centered on a specific wavelength, unlike a halogen lamp or the like.
To obtain a color image consisting of images, G images and B images,
It is necessary to provide LEDs that emit light having a spectral intensity distribution corresponding to this.

[0009]

By the way, the LED is
A light-emitting element that emits light by passing a predetermined current through a semiconductor pn junction in the forward direction. However, the emission characteristics, that is, the spectral intensity distribution of the emitted light of the LED may change depending on the junction temperature of the pn junction. Are known. In particular, the junction temperature fluctuates according to the temperature around the light source of the LED. When the light emission characteristics change due to such temperature, the spectral intensity distribution of the reading light changes with the scanner,
That is, the peak wavelength of the spectral intensity distribution shifts, and
Since the spectral intensity fluctuates, the image recorded on the film cannot be read properly.

Generally, the value of an image signal obtained by reading an image generally includes a spectral intensity distribution of read light corresponding to an R image, a G image, and a B image and a spectral density distribution (spectral transmission) of an image recorded on a film. Rate distribution) and the spectral sensitivity distribution of an image sensor such as a CCD sensor that is a reading unit of reading light containing image information.
Here, the images recorded on the film are C (cyan), M
(Magenta) and Y (yellow), the C, M, and Y dyes of the image recorded on the film are normalized by the normalized reference spectral density distributions of C, M, and Y, respectively. The density intensity of the spectral transmittance distribution is variously changed. Therefore, when the reading light is transmitted through such a film, a change in the spectral intensity distribution of the reading light, that is, a shift in the wavelength or a change in the spectral intensity causes the spectral separation of the transmitted light that passes through the film and carries an image. The intensity distribution also fluctuates. Therefore, the integrated value obtained by multiplying the spectral intensity distribution of the transmitted light by the spectral sensitivity distribution of an image sensor such as a CCD sensor and integrating it in a predetermined wavelength region also changes, and the image signal corresponding to the R image, the G image, and the B image is changed. Also fluctuates.

Fluctuations in the spectral intensity distribution include fluctuations in the peak height (fluctuations in the light emission intensity) and wavelength shifts of the mountain-shaped distribution. It is a mountain-shaped distribution, and the spectral density distributions (spectral transmittance distribution) of C, M and Y are also single mountain-shaped distributions.
When the peak position of the mountain-shaped distribution of the emission light of the LED and the peak position of the single mountain-shaped distribution of C, M and Y of the film are close to each other, the spectral intensity distribution of the LED is constant, and L
Even when the wavelength shift amount of the peak distribution of the emission light of the ED is slight, the image signal greatly varies. As described above, the image recorded on the film cannot be properly read by an image sensor such as a CCD sensor due to the fluctuation of the spectral intensity distribution of the reading light.

Japanese Patent Application Laid-Open No. 7-137338 proposes an apparatus for correcting the variation in the emission intensity distribution among the variations in the spectral intensity distribution of the light emitted from the LED. However, this apparatus does not disclose a method for correcting data in consideration of the wavelength shift amount of the spectral intensity distribution of the light emitted from the LED. As described above, even if the wavelength shift amount is small, the image is not corrected. The problem of large fluctuations in the signal remains unsolved.

Accordingly, the present invention solves the above problems,
In an image reading apparatus and an image reading method in which an image is carried on a reading light and the reading light is photoelectrically read to obtain an image signal, the image signal is appropriately adjusted even if the spectral intensity distribution of the reading light emitted from the light source fluctuates. In particular, it is an object of the present invention to provide a film scanner which can obtain an appropriate image signal by using a light emitting element and further a light emitting diode as a light source of reading light.

[0014]

In order to achieve the above object, the present invention provides a light source for emitting reading light, a reading light emitted from the light source, photoelectrically reading a reading signal, and including image information. In the case of reading light, reading means for obtaining an image signal;
Adjustment information obtaining means for obtaining fluctuation amount information of the spectral intensity distribution of the read light, and using the fluctuation amount information to obtain adjustment information for adjusting the image signal accompanying the fluctuation of the spectral intensity distribution; The present invention provides an image reading apparatus comprising: a fluctuation amount adjusting unit that adjusts the image signal based on adjustment information.

At this time, the adjustment information obtaining means obtains the wavelength shift amount and the emission intensity variation amount of the spectral intensity distribution from the spectral intensity distribution variation amount information, and obtains the wavelength shift amount and the emission intensity variation amount. It is preferable to obtain the adjustment information using Further, the adjustment information acquiring means transmits the reading light emitted from the light source to a reference filter having a predetermined spectral transmission characteristic, and uses an image signal of the reference filter which is photoelectrically read as the fluctuation amount information. It is preferable to obtain the adjustment information. Alternatively, it is preferable that the fluctuation amount information is a temperature of the light source obtained by a temperature acquisition unit, and in this case, the fluctuation amount of the spectral intensity distribution is determined in advance by the temperature of the light source and the spectral intensity distribution. It is preferable that the temperature is obtained from the temperature of the light source obtained by the temperature obtaining means, using a correspondence relationship with the fluctuation amount of the light source. Preferably, the temperature acquisition unit is a temperature sensor, or the temperature acquisition unit is a unit that obtains the temperature of the light source by obtaining the amount of infrared light emitted from the light source. In this case, it is preferable that the temperature acquisition unit receives the infrared light with the reading unit.

It is preferable that the fluctuation amount adjusting means corrects the image signal by referring to a reference table created based on the adjustment information. The image signal may be adjusted by adjusting a reading time of the reading unit based on the image signal.

The present invention also relates to an image reading method in which a reading light is emitted from a light source, image information is included in the reading light, and an image signal is read photoelectrically by reading means. By obtaining fluctuation amount information of the intensity distribution and using the fluctuation amount information, adjustment information for adjusting the image signal associated with the fluctuation of the spectral intensity distribution is obtained, and the image signal is adjusted based on the adjustment information. An image reading method is provided.

Here, in the image reading method, the wavelength shift amount and the emission intensity variation amount of the spectral intensity distribution are obtained from the variation amount information of the spectral intensity distribution, and the wavelength shift amount and the emission amount variation amount are obtained. Preferably, the adjustment information is obtained by using the following formula, and the fluctuation amount information is preferably a temperature of the light source.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image reading apparatus according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 shows a digital photo printer (hereinafter, referred to as a digital photo printer) using a scanner which is an embodiment of the image reading apparatus of the present invention.
Photo printer 10). The digital photo printer 10 shown in FIG. 1 basically includes a scanner 12 that photoelectrically reads a reading light in which an image captured on a film F is included as image information (bears an image), and An image processing device 14 automatically obtains image processing conditions from the read image data, performs image processing based on the image processing conditions, and obtains output image data. Personal computer 15 to be tested and image processing device 1
A printer 16 for exposing the photosensitive material with a light beam modulated according to the output image data obtained in step 4 and recording a latent image;
And a processor 17 that develops the exposed photosensitive material and outputs it as a print. The image reading apparatus of the present invention is not limited to a transmissive scanner that photoelectrically reads the transmitted light of the film F, such as a scanner 12 used in the photo printer 10, but also a reflection scanner obtained by irradiating a read original from a light source. The reflection type scanner which reads light photoelectrically may be sufficient.

The scanner 12 has a reading section 18 and a signal processing section 20. The reading unit 18 is a device that photoelectrically reads an image captured on a film F or the like one frame at a time.
2, a diffusion box 24, a carrier 26 for transporting and supporting the film F to a predetermined reading position, an imaging lens unit 28, a CCD sensor 30, and a shutter 31.

As the light source 22, an LED is used, which emits reading light (R reading light, G reading light, and B reading light) for reading R, G, and B images constituting a color image. Are provided on the LED array substrate corresponding to the R reading light, the G reading light, and the B reading light, respectively. In addition, on the LED substrate of the light source 22, L which emits infrared light is provided.
An ED light emitting element may be provided, and is used as a light source of reading light that is photoelectrically read by the CCD sensor 30. In this case, the infrared light is used to detect a flaw on the image recorded on the film F, and is used to correct the flaw of the image according to the detection result. As described above, it is used to obtain the temperature around the light source 22 (the temperature of the light source) which affects the fluctuation of the spectral intensity distribution. In the present invention, an LED is used as a light source. However, the light source is not necessarily limited to the LED, and a light source that emits light having a specific spectral intensity distribution, for example, a semiconductor laser element may be used.

A temperature sensor 23 is provided on the surface of the light source 22 opposite to the surface on which the LEDs are mounted. The temperature sensor 23 is a thermistor, and is configured to measure the temperature (ambient temperature) around the light source 22 and send the measurement result to the fluctuation amount acquisition unit 40 of the fluctuation amount correction unit 38. The measured temperature around the light source 22 is used to determine the amount of change in the spectral intensity distribution of each reading light (R reading light, G reading light, and B reading light) emitted by the light source 22. That is, the light source 2
Two temperatures are used as fluctuation amount information of the spectral intensity distribution in the present invention. The temperature sensor in the present invention is not limited to a thermistor, and may be a platinum resistance temperature detector or a thermocouple. Further, the installation position of the temperature sensor is not limited, and the temperature of the light source 22, that is, the LED of the light source 22.
Any position on the LED array substrate of the light source 22 may be provided as long as a temperature corresponding to the junction temperature of the light source 22 is obtained, and may be provided at a position other than this substrate. Is not limited.

The diffusion box 24 is used to make the reading light incident on the film F uniform in the surface direction of the film F, and a known one is used.

The carrier 26 is a new photo system (Advance
d Photo System), 135-type negative film and other film types and sizes, strips and slides and other film types, and trimming and other processing types.
This is a dedicated carrier that can be freely attached to the main body of the reading unit 18, and can be adapted to various films and processes by exchanging the carrier. The film F is transported frame by frame by this carrier, and each frame (image) is sequentially conveyed to a predetermined reading position. In the reading section 18 of the scanner 12, the image of each frame photographed on the film F
The reading light, the G reading light, and the B reading light sequentially read one frame at a time.

The imaging lens unit 28 is an optical lens that forms an image of the R reading light, the G reading light, and the B reading light transmitted through the film F on the light receiving surface of the CCD sensor 30, and a known lens is used. , Is not particularly limited.

The CCD sensor 30 is an area sensor for reading an image formed on the light receiving surface by the image forming lens unit 28, and includes an image sensor of 3.2 million pixels, for example. In the present invention, the CCD sensor 30 is a carrier 2
It is used as a reading means of reading light together with the imaging lens unit 6 and the imaging lens unit 28, but may be any known imaging means such as a CMOS sensor other than the CCD sensor, and is not particularly limited. Further, instead of the area sensor, a line sensor in which light receiving elements are arranged in a line in a direction orthogonal to the transport direction of the carrier 26 may be used.

The shutter 31 is a mechanical shutter that opens and closes freely so that the CCD sensor 30 receives the reading light. The shutter 31 is opened for a predetermined time.

The reading of an image by the scanner 12 is as follows.
Image reading for print output (main scan)
Prior to image processing, a pre-scan for reading an image at low resolution is performed to determine image processing conditions, etc., image processing conditions are determined based on image data obtained by pre-scan, and then a book for reading an image at high resolution. In order to perform scanning, reading is performed twice: pre-scanning and main scanning. At this time, in the pre-scan, all the images recorded on the film F to be printed out are pre-scanned in advance, and after the verification by the operator, that is, the image processing conditions are determined, the main scan is performed.

The signal processing unit 20 includes an amplifier (amplifier) 32
, An A / D converter 34, an image signal correction unit 36, and a fluctuation amount correction unit 38. Amplifier 32
Is an amplifier that amplifies the minute image signal so that the minute image signal output from the CCD sensor 30 is optimal for the input range of the A / D converter 34 at the subsequent stage. A
The / D converter 34 is a converter for digitizing the amplified image signal, and converts it into, for example, a 12-bit digital image signal.

The image signal correction section 36 is a section for performing various correction processes required for the image signal. For example, a CDS (correlated double) for removing reset noise generated when the CCD sensor 30 reads the image signal. samp
ling) correction processing by a circuit, linearity correction processing by a look-up table, smear correction processing to correct the smear phenomenon in which bright stripes in the vertical direction of the image due to light leakage occur, and scratch defects of the CCD element in pixel units Defective pixel correction processing to correct, CCD of CCD sensor 30
A dark correction process for removing charges (dark current) accumulated in the element regardless of the amount of incident light, a conversion process to density data, and a light correction process such as a shading correction are performed.

The fluctuation amount correction unit 38 includes a fluctuation amount acquisition unit 40
And a correction information acquisition unit 42 and a correction execution unit 44.
This portion corrects an image signal according to the amount of change in the spectral intensity distribution of the light source 22. That is, the fluctuation amount correction unit 38 calculates the fluctuation amount of the spectral intensity distribution of the reading light (R reading light, G reading light, and B reading light) from the measured temperature around the light source 22 sent from the temperature sensor 23, The wavelength shift amount of the mountain-shaped distribution and the variation amount of the emission intensity are obtained, and based on this,
This is a part for correcting an image signal.

The fluctuation amount acquiring section 40 measures the measured temperature obtained by the temperature sensor 23 and the light source 22 under the temperature atmosphere.
The relationship between the amount of change in the spectral intensity distribution of the read light and the amount of change in the spectral intensity distribution of the read light is stored and stored in advance, and based on the measurement result sent from the temperature sensor 23, the amount of change in the spectral intensity of the read light (wavelength shift amount and light emission) (Fluctuation amount of intensity). The obtained variation amount of the spectral intensity distribution is sent to the correction information acquisition unit 42.

The correction information acquisition section 42 is provided with a fluctuation amount acquisition section 40.
From the variation amount of the spectral intensity distribution sent from the, how the image signal obtained with the reading light of the reference spectral intensity distribution as a reference is affected by the variation of the spectral intensity distribution,
A data set of the correspondence between the reading light of the reference spectral intensity distribution and the image signal obtained by the reading light of the changed spectral intensity distribution, that is, a part for acquiring a correspondence VV ′ to be described later. The invention constitutes adjustment information acquisition means.

The correction information acquisition section 42 acquires the correspondence VV 'based on the principle described below. Actually, instead of performing the subsequent calculations, data of the correspondence VV ′ obtained by pre-calculation in association with the known identification information such as the spectral intensity distribution is recorded and stored in a ROM or the like. Then, based on the identification information, the calculation result is called out from the recorded and held to obtain the correspondence VV '.

The acquisition of the correspondence VV 'will be described in principle. As shown in the following equation (1), the normalized reference spectra of C, M and Y determined according to the type of the film F are as follows. A spectral density distribution T (λ) in which the density intensity of the density distribution (spectral transmittance distribution) is variously changed, and R at a set reference temperature
The reference spectral intensity distribution P _i (λ) (i = R, G, B) of each of the reading light, the G reading light, and the B reading light, and the CCD sensor 30
Is multiplied by the spectral sensitivity distribution S (λ), and a value V obtained by performing integration with a predetermined wavelength region as an integration interval, and as shown in the following equation (2), a value V standard spectral intensity distribution _{P i (λ) (i =} R, G, B) the spectral intensity distribution P _i obtained by the variation of the wavelength shift and emission intensity of '(λ) (i = R , G, B), the reference A value V ′ obtained by using instead of the spectral intensity distribution P (λ) is obtained. The correspondence between the value V in the reference spectral intensity distribution and the value V ′ accompanying the fluctuation of the spectral intensity distribution is obtained by variously changing the density intensity of the spectral density distribution based on the reference spectral density distribution of the film F, Moreover, since it is obtained for each of the R reading light, the G reading light, and the B reading light, the correspondence between the value V and the value V ′ corresponding to various densities of the film F (hereinafter, this is referred to as the correspondence VV ′). That is, the adjustment information for adjusting the image signal accompanying the fluctuation of the spectral intensity distribution in the present invention is obtained. The correction information acquisition unit 42 identifies the reference spectral density distribution corresponding to the type of the film F and the reference spectral intensity distribution P _i (λ) (i = R, G, B)
The data of the correspondence VV ′ is called based on the identification information of the spectral sensitivity distribution S (λ).

[0037]

(Equation 1)

(Equation 2)

In the scanner 12 of this embodiment, the LED of the light source 22 emits light every time scanning is performed.
As shown in FIG. 2 (a), the light emission characteristics of FIG. 2 show that in the initial stage of light emission, the light emission intensity increases with the light emission time, and thereafter, the light emission intensity reaches a peak and the light emission intensity gradually decreases with time. Show. Then, by repeating light emission, the junction temperature of the LED of the light source 22 becomes lower than the light source 2.
The temperature rises with the temperature around 2, the light emission characteristics fluctuate from the solid line A to the broken line B, and the light emission intensity (integral value of the spectral intensity distribution in the visible region) decreases. At the same time, the spectral intensity distribution fluctuates (wavelength shift) in the wavelength region. For example, as the junction temperature rises, the wavelength shifts to longer wavelengths.
The value V fluctuates as described above due to the fluctuation of the emission intensity and the wavelength shift of the spectral intensity distribution. In particular, FIG.
As shown in (b), the peak wavelength of the spectral intensity distribution P _i (λ) is the peak wavelength of the product T (λ) · S (λ) of the spectral density distribution T (λ) and the spectral sensitivity distribution S (λ). If it is close to
Even when the shift amount of the peak wavelength is small, the product P _i '
(Λ) · T (λ) · S (λ) is the product P _i (λ) · T
(Λ) · S (λ), the difference between the value V ′ and the value V is large. In particular, the spectral density distribution T (λ) of the film F
Has a single mountain-shaped distribution, so the spectral density distribution T (λ)
Is closer to the peak wavelength of the spectral intensity distribution P _i (λ), the difference between the value V ′ and the value V increases. The correspondence VV ′ corresponding to such various density intensities is sent to the correction executing unit 44.

In this embodiment, the fluctuation amount obtaining section 40 obtains the fluctuation amount of the spectral intensity distribution using the measured temperature measured by the temperature sensor 23, and the correction information obtaining section 4 obtains the fluctuation amount from the fluctuation amount.
In step 2, the correspondence VV ', which is the adjustment information for correcting the image signal, is obtained. The correspondence VV' corresponding to the information on the temperature measured by the temperature sensor 23 and the type of the film F is obtained.
Is recorded and held in advance, and a direct correspondence VV ′ is directly obtained from the measurement result measured by the temperature sensor 23 and the type of the film F without obtaining a variation amount of the spectral intensity distribution, and is sent to the correction execution unit 44. It may be configured as follows.

The correction executing unit 44 creates and holds a reference table for a correction process applied to an image signal using the sent correspondence VV ′,
6 is a section for obtaining an image signal that would be obtained when the reading light having the reference spectral intensity distribution is emitted by referring to the reference table from the image signal sent from the controller 6. This is the part corresponding to the means. The image signal appropriately corrected by the fluctuation amount correction unit 38 in this manner is sent to the image processing device 14 as image data. The variation adjusting means in the present invention is not limited to a means for performing correction using a reference table, but may be a means for performing conversion mapping using a conversion function or a conversion matrix obtained from adjustment information.

The signal processing section 20 is configured as described above. The signal processing section 20 may be processed by a dedicated circuit formed on a dedicated circuit board, or may be processed by a computer to execute a predetermined process. It may be processed by software that performs a function, or may be processed by using both a dedicated circuit and software.
Further, the scanner 12 is provided with a control unit that controls and manages the operation of the reading unit 18 and the signal processing unit 20.

The image processing apparatus 14 is a part for performing image processing on the transmitted image data, and is an auto setup unit 14a for setting processing conditions for image processing.
And an image processor 14b for performing image processing on the image data.

The auto set-up unit 14a creates a density histogram based on the image data read by the pre-scan, average density, LATD (large area transmission density), highlight (lowest density), shadow (highest density). )
The image processing conditions are determined, and the image processing conditions are determined.
Send to Among the image processing conditions, the reading conditions at the time of reading the main scan performed by the scanner 12, for example, the conditions such as the accumulation time (reading time) of the CCD element by the electronic shutter of the CCD sensor 30 are transmitted to the control unit of the scanner 12. Can be

The image processor 14b includes the scanner 1
This is a portion that performs predetermined image processing on the image data that has been completely scanned in step 2 according to the determined image processing conditions. For example, gradation conversion, color conversion, hypertoning processing to compress the gradation of the ultra-low frequency luminance component of an image, hypersharpness processing to enhance sharpness while suppressing graininess, and electronic transformation to scale to a predetermined output image size Double processing and the like are performed by a known method. The processed image data is
The data is sent to the printer 16. Further, the image data is sent to the personal computer 15 as needed, and the image data is recorded on a recording medium such as a floppy disk or CD-R.

The personal computer 15 performs image processing on the image data obtained by the pre-scan using the image processing conditions obtained by the auto setup 14a, and performs image processing in order to receive an operator's test. A display, a keyboard, and a mouse (both not shown) are connected. Personal computer 1
5 determines, in addition to the image processing conditions obtained by the auto setup unit 14a, image processing conditions for gray balance adjustment, dodging processing, saturation correction, and the like, which are performed as necessary, in accordance with an operator's instruction; Integrating the obtained image processing conditions, performing predetermined image processing according to the image processing conditions,
The result of the image processing is displayed on a display for verification.

The printer 16 is a printing device for exposing a photosensitive material (photographic paper) in accordance with the supplied image data to record a latent image. The processor 17 is a developing device that performs predetermined processing on the exposed photosensitive material and outputs the processed material as a print. In the printer 16, for example, after cutting the photosensitive material into a predetermined length corresponding to the print, a back print is recorded, and then, R exposure according to the spectral sensitivity characteristics of the photosensitive material,
An image processing apparatus 1 for the three types of light beams of G exposure and B exposure
The light beam is conveyed in the sub-scanning direction orthogonal to the main scanning direction by modulating the light-sensitive material in the main scanning direction and modulated in accordance with the image data output from the photodetector 4, thereby two-dimensionally transforming the photosensitive material by the light beam. The latent image is recorded by scanning exposure and supplied to the processor 17. Processor 1 that received the photosensitive material
Reference numeral 7 performs a predetermined wet development process such as color development, bleach-fixing, washing with water, etc., and forms a print by drying. The print is sorted into a predetermined unit such as one film and accumulated.

In the above embodiment, the light source 22 measured by the temperature sensor 23 as the variation amount information of the spectral intensity distribution is used.
In the present invention, an infrared light is emitted from the LED of the light source 22 and the CCD sensor 3 is used.
The infrared light may be read at 0, and the temperature around the light source 22 may be obtained from the read infrared light read signal. That is, the infrared light read signal processed by the image signal correction unit 36 is configured to be sent to the fluctuation area acquisition unit 40, and the light amount received from the infrared light read signal is obtained by the fluctuation amount acquisition unit 40,
The temperature around the light source 22 (LED) may be obtained from this light amount. Thus, the temperature around the light source 22 can be obtained from the read signal of the infrared light because the read signal originally corresponds to the amount of light received, and the emission intensity of the infrared light that determines the magnitude of the received light is the light source 22 This is because it depends on the surrounding temperature.

In this case, the fluctuation amount acquisition unit 40 includes the light source 2
In addition to the correspondence between the temperature around the light source 22 and the amount of change in the spectral intensity distribution of the reading light emitted from the light source 22 under the temperature atmosphere, the temperature around the light source 22 and the emitted infrared light are measured using a CCD.
The relationship with the value of the read signal obtained by receiving light by the sensor 30 is recorded and held in advance, and the light source 2 is obtained from the obtained read signal of infrared light.
The temperature around the light source 22 may be obtained, and the amount of change in the spectral intensity distribution may be obtained from the obtained temperature around the light source 22, and the obtained amount of change may be sent to the correction information obtaining unit 42.

When the temperature around the light source 22 is determined using infrared light, the film F
The temperature around the light source 22 may be obtained by using a read signal obtained when the transmitted light is read by irradiating the infrared light to the. The reason that the infrared light transmitted through the film F can be used as described above is that the infrared light does not carry image information in the visible region recorded on the film F. That is, even if the spectral intensity distribution of the infrared light is shifted in wavelength, the infrared light transmitted through the film does not carry an image in the visible region of the film F, and C
This is because the reading of the light amount by the CD sensor 30 is not affected. Further, the value of the read signal of the infrared light read by the CCD sensor 30 and the correspondence VV ′, which is the adjustment information for correcting the image signal, are recorded and held in advance,
A read signal of the infrared light obtained by reading the infrared light with the CCD sensor 30 is used as fluctuation amount information of the spectral intensity distribution, and from this, a direct correspondence V-V 'is obtained without obtaining the temperature around the light source 22. Is also good.

As the adjustment information acquisition means in the present invention,
A reference filter having a predetermined spectral characteristic in the visible region is provided. The reading light emitted from the light source 22 is transmitted through the reference filter, photoelectrically read by the CCD sensor 30, and a spectral intensity distribution is obtained from an image signal of the obtained reference filter. The amount of fluctuation, that is, the amount of wavelength shift and the amount of fluctuation in emission intensity are directly obtained,
The correspondence VV ′ may be obtained from the amount of change.

That is, before reading the film F,
A filter having a known spectral density distribution is inserted in the optical path of the reading light instead of the film F, and read by the CCD sensor 30 using the reading light (R reading light, G reading light, and B reading light), and the reference filter obtained. The amount of change in the spectral intensity distribution is directly obtained from the image signal, the known spectral density distribution of the reference filter, and the known spectral sensitivity distribution of the CCD sensor 30. That is, the reference filter image signal read by the reference filter is used as the fluctuation amount information in the present invention. In this case, the obtained fluctuation amount is, as in the above embodiment,
The correction information acquiring unit 42 is used to obtain the correspondence VV ′. The reference filter is preferably provided with a plurality of filter regions having different spectral density distributions to such an extent that the amount of change in the spectral intensity distribution is determined for each reading light.
Alternatively, a reference image signal read by transmitting the reading light of the reference spectral intensity distribution through the reference filter is recorded and held in advance,
The image signal read by transmitting the reading light through the reference filter may be made to correspond to the recorded and held reference image signal to directly obtain the correspondence VV ′. Also in this case, the reference filter has a correspondence VV ′ corresponding to each reading light.
It is preferable that a plurality of filter regions having different spectral density distributions are provided to such an extent that is obtained.

The reading of the infrared light and the transmitted light of the reference film need not necessarily use the CCD sensor 30 that scans and reads the film F.
A dedicated reading unit provided separately from the sensor 30 may be used. As described above, since the correspondence VV 'can be directly obtained without obtaining the temperature around the light source 22, it is also possible to correct fluctuations in the spectral intensity distribution other than temperature factors such as the junction temperature.

Further, in the above-described example, the amount of change in the spectral intensity distribution is obtained by reading the infrared light and the transmitted light of the reference film. May be used in various combinations in combination to determine the amount of change in the spectral intensity distribution. More accurate fluctuation amount correction can be performed using a plurality of fluctuation amounts obtained in combination.

Further, in this embodiment, the fluctuation amount adjusting means performs correction on the image signal in the correction executing section 44 of the fluctuation amount correcting section 38, but based on the fluctuation amount of the spectral intensity distribution. An adjusting unit that adjusts the image signal in advance by adjusting the reading time (charge accumulation time) of the reading unit that photoelectrically reads the reading light may be used. That is, the opening and closing time of the electronic shutter of the CCD sensor 30 is controlled by a control unit (not shown) of the signal processing unit 20,
The reading time of the image sensor of the CD sensor 30 may be adjusted. This is because by adjusting the reading time, it is possible to adjust the amount of light according to the change in the emission intensity of the spectral intensity distribution.

The photo printer 10 is configured as described above. Next, the image reading method of the present invention will be described based on the operation of the photo printer 10.

The carrier 26 corresponding to the film F is loaded into the reading section 18 of the scanner 12, the film F (cartridge) is set at a predetermined position of the carrier 26, and the type of the film F to be read and the print size to be created are determined. After inputting necessary instructions, the user instructs to start printing.
As a result, the charge accumulation time of the CCD sensor 30 is set in accordance with the prescan reading conditions. Thereafter, the carrier 26 pulls out the film F from the cartridge and transports the film F in the sub-scanning direction at a speed corresponding to the prescan. The scanning is started, and the reading light (R reading light, G reading light and B reading light) emitted from the light source 22 forms an image on the light receiving surface of the CCD sensor 30 at the predetermined reading position as described above, and An image captured in F is read photoelectrically for each of R, G, and B images.

When the reading light is emitted from the light source 22, the temperature around the light source 22 is measured by the temperature sensor 23, and the measurement result is sent to the fluctuation amount acquiring unit 40.

The image signal output from the CCD sensor 30 by the pre-scan is amplified by the amplifier 32,
The digital image signal is sent to the converter 34 and converted into a digital image signal. The digital image signal is sent to the image signal correction unit 36, subjected to predetermined correction processing such as CDS correction and linearity correction described above, and sent to the variation correction unit 38.

The fluctuation amount acquisition unit 40 of the fluctuation amount correction unit 38 calculates the measured temperature obtained by the temperature sensor 23 and the measured temperature, which are recorded and held in advance, based on the measurement result of the temperature around the light source 22 sent from the temperature sensor 23. Using the relationship with the variation in the spectral intensity distribution of the reading light emitted from the light source 22 under the atmosphere, the variation in the spectral intensity distribution of the reading light emitted during the prescan reading is obtained. The obtained fluctuation amount is sent to the correction information acquisition unit 42.

The correction information acquisition section 42 obtains the variation of the spectral intensity distribution from the variation of the spectral intensity distribution, and uses this to perform correction from the spectral density distribution with various density intensities as described above. Relationship VV 'which is adjustment information for
Is obtained. This correspondence relationship VV ′ is stored in the correction execution unit 4.
4 The correction executing unit 44 creates a reference table of the image signal based on the sent correspondence VV ′. On the other hand, the image signal read by the CCD sensor 30, processed by the image signal correction unit 36, and sent to the correction execution unit 44 is subjected to correction processing using a reference table of the correction execution unit 44, Image processing device 14 as data
Sent to As described above, since the image signal is corrected by using the temperature around the light source 22 of the spectral intensity distribution of the reading light, the image signal can be appropriately obtained even if the spectral intensity distribution of the light source fluctuates. In particular, among a plurality of frames recorded on the film F, a difference in image density and a difference in color between the read first frame and the last frame are reduced.

The auto-setup section 14a of the image processing apparatus 14 automatically sets the image processing conditions based on the image data read by the pre-scan, and sends the image processing conditions to the personal computer 15. The reading conditions among the image processing conditions are sent to the control unit of the scanner 12.

The personal computer 15 performs image processing on the pre-scanned image data using the transmitted image processing conditions, and displays the processed image in order to receive an operator's test. You. The image processing conditions are adjusted in the personal computer 15 based on the instruction of the operator until the operator passes the test. After passing the operator's certification, the personal computer 15 sends the automatic setup unit 1
The image processing conditions are sent to the image processor 14b via 4a, and are recorded in the memory unit of the image processor 14b.

Such a verification process is continuously performed on all the images of the film F to be printed out. After that, the main scan is started. The reading of the image by the reading unit 18 and the respective processes of the signal processing unit 20 in the main scan are performed in the same manner as in the pre-scan, and are performed by the image processing apparatus 14.
Sent to In the image processing device 14, the image processing conditions recorded in the memory unit of the image processor 14b are called in accordance with the frame of the film F, and image processing is performed according to the called image processing conditions. The processed image data is sent to the printer 16.

The printer 16 cuts the photosensitive material into a predetermined length corresponding to the print, records a back print, and then performs R exposure according to the spectral sensitivity characteristics of the photosensitive material.
The three types of light beams of the G exposure and the B exposure are modulated according to the image data output from the processing device 14 to be deflected in the main scanning direction, and to convey the photosensitive material in the sub scanning direction orthogonal to the main scanning direction. The latent image is recorded by two-dimensionally scanning and exposing the photosensitive material with the light beam, and the processor 1
7 Processor 17 that received the photosensitive material
Is subjected to a predetermined wet development process such as color development, bleach-fixing, washing with water and the like, dried to form a print, sorted into a predetermined unit such as one film and accumulated.

Although the image reading apparatus and the image reading method of the present invention have been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the gist of the present invention. Of course you can do it.

[0066]

As described above in detail, according to the present invention, information on the amount of change in the spectral intensity distribution of the reading light is obtained, and by using this information on the amount of change, the image accompanying the change in the spectral intensity distribution is obtained. Since adjustment information for signal adjustment is obtained and the image signal is adjusted based on the adjustment information, an image signal can be properly obtained even if the spectral intensity distribution of the reading light emitted by the light source fluctuates. . In particular, in the case of reading light having a single mountain-shaped spectral intensity distribution, such as light emitted from an LED,
By obtaining the wavelength shift amount of the spectral intensity distribution and the variation amount of the emission intensity, an appropriate image signal can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating a digital photo printer including a scanner as an example of an image reading apparatus according to the present invention.

FIGS. 2A and 2B are diagrams illustrating a change in an issue intensity, and FIG. 2B is a diagram illustrating a change in a spectral intensity distribution.

[Explanation of symbols]

 Reference Signs List 10 digital photo printer 12 scanner 14 image processing device 15 personal computer 16 printer 17 processor 18 reading unit 20 signal processing unit 22 light source 23 temperature sensor 30 CCD sensor 32 amplifier 34 A / D converter 36 image signal correction unit 38 variation correction unit 40 fluctuation amount acquisition unit 42 correction information acquisition unit 44 correction execution unit

Claims (13)

[Claims] A light source that emits reading light; a reading unit that photoelectrically reads a reading light emitted from the light source and obtains an image signal when the reading light includes image information; Obtaining the fluctuation amount information of the spectral intensity distribution of, and using this fluctuation amount information, adjustment information obtaining means for obtaining adjustment information for adjusting the image signal accompanying the fluctuation of the spectral intensity distribution; and An image reading device comprising: a fluctuation amount adjusting unit that adjusts the image signal based on the image signal. 2. The apparatus according to claim 1, wherein the adjustment information obtaining means obtains a wavelength shift amount and a light emission intensity fluctuation amount of the spectral intensity distribution from the change amount information of the spectral intensity distribution. The image reading apparatus according to claim 1, wherein the adjustment information is obtained by using the following. 3. The adjustment information acquiring means transmits read light emitted from the light source to a reference filter having a predetermined spectral transmission characteristic, and converts an image signal of the reference filter read photoelectrically into the variation amount information. The image reading apparatus according to claim 1, wherein the adjustment information is obtained by using the information. 4. The image reading apparatus according to claim 1, wherein said fluctuation amount information is a temperature of said light source obtained by a temperature obtaining means. 5. The variation of the spectral intensity distribution is determined by using a correspondence relationship between the temperature of the light source and the variation of the spectral intensity distribution determined in advance, and calculating the temperature of the light source obtained by the temperature acquisition unit. The image reading device according to claim 4, wherein the image reading device is obtained from the following. 6. An image reading apparatus according to claim 4, wherein said temperature acquisition means is a temperature sensor. 7. An image reading apparatus according to claim 4, wherein said temperature obtaining means obtains the temperature of said light source by obtaining the amount of infrared light emitted from said light source. 8. The image reading apparatus according to claim 7, wherein said temperature acquisition means receives said infrared light by said reading means. 9. The image reading apparatus according to claim 1, wherein said fluctuation amount adjusting means corrects said image signal by referring to a reference table created based on said adjustment information. 10. The image reading apparatus according to claim 1, wherein said fluctuation amount adjusting means adjusts said image signal by adjusting a reading time of said reading means based on said adjustment information. . 11. An image reading method in which a reading light is emitted from a light source, image information is included in the reading light, and an image signal is read photoelectrically by a reading unit, wherein a variation in a spectral intensity distribution of the reading light is provided. Amount information, and using the fluctuation amount information, obtains adjustment information for adjusting the image signal accompanying the fluctuation of the spectral intensity distribution, and adjusts the image signal based on the adjustment information. Image reading method. 12. A wavelength shift amount and a light emission intensity fluctuation amount of the spectral intensity distribution are obtained from the spectral intensity distribution change amount information, and the adjustment information is obtained by using the wavelength shift amount and the light emission intensity fluctuation amount. 12. The image reading method according to claim 11, wherein the image reading is performed. 13. The image reading method according to claim 11, wherein the fluctuation amount information is a temperature of the light source.