JPH1013679A - Method and device for reproducing image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always obtain the effect of satisfactory mask print even for regenerative images in different sizes when reproducing visible images from digital photographic image signals. SOLUTION: Plural kinds of low-pass filters(LPF) 16a, 16b and 16c are prepared for preparing blurred images in different mask sizes from digital image signals. Among these LPF, any LPF in the mask size corresponding to the pixel density of image to be reproduced is selected by a selector 16d to be operated by a reproducing size input means 16e and while using that selected LPF, the blurred image signal is prepared. Then, a differential signal is provided by subtracting corresponding picture elements between the digital image signal and the blurred image signal, and a processed image signal provided by performing prescribed image processing to that differential signal is defined as a visible image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reproducing method and apparatus for reproducing a visible image such as a photographic print from a photographic film photographed by a camera. An image to be subjected to a dodging process that eliminates overexposure (a distant view with high brightness becomes completely white due to loss of contrast) and blackening (a face of a person in low-brightness backlight loses contrast and becomes black). The present invention relates to an improvement in a reproducing method and an apparatus.

[0002]

2. Description of the Related Art In recent years, image information recorded on a photographic film (hereinafter, referred to as a film) such as a negative film or a reversal film or a printed matter is photoelectrically read, and the read image is converted into a digital signal. Digital photo printers are being developed which perform image processing described above to obtain image information for recording, and scan and expose a photosensitive material such as photographic paper with a recording light modulated according to the image information for printing.

[0003] Digital photo printers use various types of images, such as editing of a plurality of images, editing of image division, etc., editing of characters and images, printing image layout, color / density adjustment, scaling, and edge enhancement. Processing can be performed freely, and a print that has been freely edited and image-processed can be output according to the application. Further, in the conventional printing using surface exposure, all the image density information recorded on a film or the like cannot be reproduced due to the restriction of the reproducible density range of the photosensitive material. It is possible to output a print in which almost 100% of the image density information is reproduced.

[0004] Such a digital photo printer basically includes a reading means for reading an image recorded on a document such as a film, an image processing of the read image, and determining exposure conditions to be performed later, and according to the determined exposure conditions. It comprises an image reproducing means for subjecting the photosensitive material to scanning exposure to carry out a developing process and displaying on a monitor.

In an apparatus for reading an image recorded on a film or the like, for example, when reading by slit scanning, 1
The film is irradiated with a slit-shaped reading light extending in the two-dimensional direction, and the film is moved in a direction substantially orthogonal to the one-dimensional direction (or the reading light and the photoelectric conversion element are moved), so that the film is two-dimensionally moved. Scans dimensionally.
The transmitted light carrying the film image transmitted through the film is:
An image is formed on a light receiving surface of a photoelectric conversion element such as a CCD line sensor, photoelectrically converted, and read. The read light amount data is amplified, converted into a digital signal by A / D conversion, subjected to various types of image processing such as correction of variations in characteristics of each CCD element, density conversion, magnification conversion, and the like, and transferred to a reproducing unit. You.

[0006] The reproducing means reproduces the transferred image information as a visible image on a display such as a CRT. The operator looks at the reproduced image, and if necessary, further applies corrections such as gradation correction and color / density correction to the reproduced image (setting of setup conditions), and the reproduced image passes as a finished print (test OK). ), The image data is transferred to a developing unit or a monitor as image information for recording.

In an image reproducing apparatus, if image recording by raster scan (light beam scanning) is used, a photosensitive layer of three primary colors formed on a photosensitive material, for example, exposure of three colors of R, G and B Are modulated in accordance with the image information for recording and are deflected in the main scanning direction (corresponding to the one-dimensional direction), and the photosensitive material is shifted in a direction substantially orthogonal to the main scanning direction. (Sub-scanning is relatively performed between the deflected light beam and the photosensitive material)
Thus, the photosensitive material is two-dimensionally scanned and exposed by the light beam modulated according to the recorded image, and the read image of the film is recorded on the photosensitive material.

The exposed light-sensitive material is then subjected to a development process in accordance with the light-sensitive material, for example, in the case of a silver halide photographic material, a development process such as color development / development → bleaching / fixing → washing → drying is carried out to obtain a finished print Is output as

The brightness range of a subject on which such a photosensitive material can be recorded is relatively wide, but the maximum density of the photosensitive material is limited. Part) or a dark part (dark part) tends to be crushed.
For example, when a person is photographed in backlight, if the person is printed so that it is clear, bright parts such as the sky will be white, and if the bright parts such as the sky are clear, the person will be black. It will collapse. To solve this problem, methods such as dodging and masking printing are used.

Dodging gives normal exposure to areas of intermediate density in a scene, and to areas that are likely to be white on prints (for example, distant parts of the scene including distant mountains as a background of a person). Use a perforated shielding plate to selectively provide long-time exposure, or use a shielding plate to selectively shorten the exposure time in areas where prints are likely to be blackened (for example, a person in backlight). By doing so, it is possible to maintain the contrast of each subject and obtain a print in which bright and dark portions are not collapsed, for example, a print in which a distant view and a person can be seen with an appropriate contrast. As the shielding plate for locally controlling the exposure time in this way, using a photographic image of a blur image obtained by inverting the negative / positive of the original film,
A method has been proposed in which an original image film and a blurred image film are overlaid and printed.

[0011]

By the way, for images of the same subject but different resolutions (different sizes),
In order to obtain the same degree of dodging effect, the degree of blur must be the same for the subject.

However, in the above-mentioned dodging, since the operation is performed using a blur image of a fixed mask size prepared regardless of the size of the reproduced image, the print size and the monitor display size are different, and the image density is low. In the case of different images, the degree of blur for the same subject is different.For example, since the degree of blur is different for the face of the same subject, the effect of dodging differs depending on the size, and there is a problem that appropriate dodging processing cannot always be performed. there were. In particular, when performing the dodging processing parameter test on the monitor display image, the problem that the monitor display image does not match the print image is serious.

SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide an image reproducing method and apparatus which can always obtain the same dodging effect even for reproduced images of different sizes.

[0014]

According to the present invention, there is provided an image reproducing method and apparatus for reproducing a visible image from a digital image signal as described above. Prepare multiple types of low-pass filters to create
A low-pass filter having a mask size corresponding to the pixel density of the image to be reproduced is selected from the plurality of types of low-pass filters, and a blur image signal representing a blur image of the photographic image is created using the selected low-pass filter. Then, a difference signal is obtained by performing a subtraction between signals of pixels corresponding to the digital image signal and the blurred image signal,
A predetermined image processing is performed on the difference signal to obtain a processed image signal, and the processed image signal is reproduced as a visible image.

Here, selecting a low-pass filter having a mask size corresponding to the pixel density of an image to be reproduced means selecting a low-pass filter according to a "print size" to be reproduced. In other words, not only the print size but also the image for monitor display in a system using the same device always has a fixed size, so the image to be reproduced depends on whether it is an image for monitor display or print. And selecting a low-pass filter.

Here, as a specific method of generating the blurred image signal, it is preferable to convert the digital image signal into a light and dark signal and perform a filtering process on the light and dark signal to generate a blurred image signal. Further, the blurred image signal may be created by photoelectrically reading a projection image obtained by optically blurring the color image.

Further, in the case of performing a prescan for measuring the obtained color image signal in advance, a blur signal of a thinned signal obtained by a prescan in which a digital signal is thinned at a predetermined interval is created, and the blur signal is thinned. The blurred image signal may be generated by interpolating the intervals.

[0018]

The image reproducing method and apparatus according to the present invention provide a plurality of types of blurred images having different mask sizes in a dodging process for preventing the images in both the light and dark areas from being destroyed. Prepare a low-pass filter, and from among these multiple types of low-pass filters, the pixel density (print size) of the image to be reproduced
Since a low-pass filter with a mask size according to is selected and a dodging process is performed using a blurred image signal created using the selected low-pass filter,
The same dodging effect can always be obtained even for reproduced images of different sizes.

Also, by forming a blurred image signal by photoelectrically reading a projected image obtained by optically blurring the color image, a blurred image signal can be compared with a blurred image signal obtained by calculation using a blur mask filter, for example. This eliminates the need for means for performing calculations, and can simplify the configuration of the apparatus.

Further, in the case of performing a prescan for measuring the obtained color image signal in advance, a blur signal of the thinned signal obtained by the prescan for detecting the light transmitted through the film by thinning out the digital signal at a predetermined interval is created. By creating a blurred image signal by interpolating the thinned-out signal of the blurred signal, a blurred image can be obtained using a signal obtained in a process necessary for reproducing a digital image signal representing a color image as a visible image. Since an image signal is created, efficient image reproduction can be performed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a first embodiment of the image reproducing apparatus according to the present invention. As shown in FIG. 1, the image reproducing device 1 according to the first embodiment of the present invention includes an image reading unit 1A and an image processing unit 1B. Image reading unit 1A
Is a light source 2, a light control unit 3 for adjusting the amount of light from the light source 2, an RGB filter 4 for converting the light from the light source 2 into three colors of RGB, and a light transmitted through the RGB filter 4. A mirror box 5 for diffusing and irradiating the film 6 with light;
And a lens 7 for forming an image on D8. The image reading method may be a method of relatively moving a line sensor instead of an area type CCD, or a method of spot metering like a drum scanner.

On the other hand, the image processing section 1B includes an amplifier 10 for amplifying the RGB three-color image signals detected by the CCD 8, and converts the amplified image signals into digital image signals.
A / D conversion means 11 for performing A / D conversion, a look-up table (LUT) 12 for converting a digital image signal into a density signal,
Frame memories 13R, 13G, 13 for storing for each color of GB
B, a matrix (MTX) 14 for obtaining a signal S _A by correcting the digital image signal so as to be a color signal that can be reproduced in an appropriate color on a photosensitive material described later, and a signal S _A and MTX15 for converting a low-pass filter (LPF) 16 for a light and dark signal and blur signal, and LUT17 to obtain an unsharp image signals S _B to adjust the contrast of the blur signal, the signal from the signal S _a S Subtraction means 18 for subtracting _B to obtain difference signal Ssub; LUT 19 for correcting contrast of difference signal Ssub; and D / A conversion means for D / A conversion of contrast-corrected signal S
It consists of 20, 21.

Here, the LUT 17 stores table data for giving a gradation curve as shown in FIG.
The gamma characteristic is such that the larger the input signal value is, the more the output signal value is slightly increased, and the nonlinearity becomes non-linear. The LUT 19 stores table data giving a gradation curve as shown in FIG. 3, and has a non-linear γ characteristic in which the larger the input signal value, the smaller the output signal value. ing. Here, the contrast of the image signal obtained as a result of a series of image processing by the LUTs 17 and 19 is 1-
Determined by the value of (γ of LUT17), the local contrast is (1− (γ of LUT17)) × (γ of LUT19)
Is determined by The γ of the LUT 17 may be changed according to the large area contrast of the entire screen (for example, in the case of a backlight scene, the difference between the brightness of the background and the main subject). It has been found that the local contrast is preferably made substantially constant irrespective of the contrast of the entire screen. Therefore, LU
T19 is linked with LUT17 (1− (γ of LUT17)) ×
It is preferable to set the value of (γ of the LUT 19) to be substantially constant. Therefore, in the present embodiment, L
The UT 17 has a γ characteristic as shown in FIG. 2 and the LUT 19 has a γ characteristic as shown in FIG.
The value of γ) of the UT 19 is made substantially constant.

On the other hand, the MTX 14 is a matrix for finishing a read image signal into an appropriate color, and is suitable for a combination of the spectral characteristics of the film 6 and the spectral characteristics of a photosensitive material from which an image is finally reproduced. The image signal is corrected so as to be reproduced in a proper color. MTX15 is
It converts an RGB color image signal into a light / dark signal, and converts the color image signal into a light / dark signal using one-third of the average value of each of the RGB image signals or the YIQ standard.

The LPF 16 is a blur mask filter for two-dimensionally blurring an image signal, and has a characteristic as shown in FIG. Here, if the diameter of the blur mask is too small, the sharpness will be unnaturally emphasized, and the overshoot at the edge portion will be conspicuous. On the other hand, when the main subject is small, there is a disadvantage that the effect of the blur mask does not appear so much or that the amount of calculation increases and the scale of the apparatus increases. As a result of experiments on various scenes by the present applicant, the diameter of the half width of the mask size in the case of 135 film is 0.3 to 3 mm on the film.
(More preferably, about 0.5 to 2 mm. When the film size is larger than 135 film, it is preferable to increase the size of the blur mask.)

Further, the intensity of the saturation of the image signal obtained as a result of the series of image processing is (MTX14) × (1- (γ of LUT 17) × (MT
X15)) × (γ of LUT19). Therefore, the color reproducibility can be freely controlled by appropriately determining the MTX and LUT coefficients in the above equation. Also,
By using MTX15 as a matrix for converting a color signal into a light-dark signal, it is possible to apply a blur mask while maintaining the color reproducibility of an edge portion of a subject, and at the same time, to simplify the configuration of a circuit for performing the above calculation. can do.

Further, in order to make the color reproducibility of the print constant when the value of γ of the LUT 17 for controlling the intensity of the blur mask effect depending on the image is changed, the value of the above expression is substantially equal. The values of MTX12 and / or MTX15 may be changed in conjunction with each other so as to be constant.

In the present invention, a plurality of types of LPFs 16 having different mask sizes are prepared as the LPF 16, and a low-pass filter having a mask size corresponding to the pixel density of an image to be reproduced is selected from the plurality of types of low-pass filters. To create a blurred image signal and perform dodging processing.

FIG. 7 shows an example of a configuration in which a plurality of types of LPFs 16 having different mask sizes are prepared and a suitable low-pass filter is selected from them.

In the example shown in FIG. 7, three low-pass filters, LPF 16a having a large mask size for monitor display, LPF 16b having a small mask size for small-size printing, and LPF 16c having a large mask size for large-size printing, have a size of three. They are connected in parallel so as to be used alternatively by a selector 16d switched by an input means 16e. The size input means 16e is for inputting a signal corresponding to the size of an image to be reproduced. The size input means 16e is connected to input means for setting a print size to the printer, and a signal may be received therefrom. It is also possible to detect the size of the set color photographic paper and output a signal. Alternatively, a setting signal for monitor display may be received, and the LPF 16a for monitor display may be selected accordingly. In any case, any form may be used as long as a signal for selecting a low-pass filter having a mask size corresponding to the pixel density of an image to be reproduced is input to the selector 16d.

According to the above-described embodiment, the selector 16d is switched by the size input means 16e, and the LPF 16a having a large mask size for monitor display, the LPF 16b having a small mask size for small size printing, and the LPF 16b having large mask size for large size printing. Of the three low-pass filters of the LPF 16c having a large mask size, a low-pass filter corresponding to the information on whether the print size or the monitor display is input by the size input means 16e is selectively used by switching the selector 16d. Is done. As a result, a blur mask having a mask size suitable for the pixel density of the reproduced image is set, a blurred image signal is generated, and a dodged image suitable for the size of the reproduced image is reproduced.

Next, the operation of the above embodiment will be described with reference to FIGS. First, the light source 2 of the image reading unit 1A
The light is emitted by the light control unit 3 and is converted into a predetermined amount of light. This light amount is set, for example, such that the transmitted light amount at the lowest density point of the image recorded on the film 6 measured in advance is slightly lower than the saturation level of the CCD 8. The light passes through the RGB filter 4, is diffused by the mirror box 5, and is irradiated on the film 6. The transmitted light of the film 6 modulated according to the image recorded on the film 6 is applied to the CCD 8 through the lens 7 and is photoelectrically converted into an image signal representing the image recorded on the film 6. In the present embodiment, it is assumed that a scene including a catch light 31 which reflects sunlight as a backlit image as shown in FIG. Here, by switching the RGB filters 4 to R, G, and B, three-color image signals representing a color image are obtained and sent to the image processing unit 1B.

The following processing is performed in the image processing section 1B. Since the image signal obtained by the image reading section 1A is weak, the image signal is amplified by the amplifier 10 and then converted into a digital image signal by the A / D converter 11. The digital image signal is converted into a density signal by the LUT 12 and stored in the frame memories 13R, 13G, and 13B. Next, the image signals stored in the frame memories 13R, 13G, and 13B are read out, and the color is corrected by the MTX 14. Here, the MTX 14 corrects the digital image signal so that colors are reproduced by matching the spectral characteristics of the film 6 with the spectral characteristics of the photosensitive material from which the image is finally reproduced, as described above. The digital image signal S _A that has been color-corrected by the MTX 14 is input to a subtraction means 18 described later. Here, the digital image signal S _A input to the subtraction means 18 is a signal 32 having a profile as shown in the II section of the image 30 shown in FIG. 5B. The relationship between the digital image signal S _A and the final print density is as follows. That is, in the gradation curve 35 representing the relationship between the signal value and the print density, the area where the subject can be reproduced without being crushed is the area G indicated by the broken line in FIG.
Therefore, in the digital image signal S _A , the image 30
The catch light part and the human part of this area G
If you print the signal on the photosensitive material as it is, the catchlight part will be white,
The human part turns black and the image collapses. Therefore, the present invention enables printing on a photosensitive material without crushing such overly bright and dark portions by performing the following processing.

First, the digital image signal S _A is subtracted by the subtraction means 18.
, While the signal S _A is duplicated and converted by the MTX 15 into a light / dark signal. Here, the MTX 15 converts a color image signal into a light and dark signal using one third of the average value of each of the RGB image signals or the YIQ regulation as described above.

The light / dark signal thus obtained is then converted into a blur mask signal by the LPF 16. And this unsharp mask signal is gradation-converted by the LUT 17, thereby being converted into the unsharp image signals S _B. The unsharp image signals S _B shown in FIG. 5 (c). When the digital image signal S _A is compared with the blurred image signal S _B , the catch light portion or the human portion of the digital image signal S _A is blurred in the blurred image signal S _D. That is, the high frequency components of the digital image signal S _A disappears, has become one represented by only the low-frequency components.

[0037] Then, the digital image signals S _A from the unsharp image signals S _B of the subtraction is performed in the difference signal Ssub is obtained in the subtracting means 18. This difference signal is shown in FIG. FIG.
As shown in (d), the difference signal Ssub is different from the digital image signal S _A shown in FIG. 5 (a) in that the catch light portion or the human portion of the digital image signal S _A is removed, and the signal range is also reduced. It is within the area G. The difference signal Ssub thus obtained is subjected to gradation conversion, density conversion, and the like by the LUT 19, and is converted to the D / A converter 20 or the D / A converter 20.
The signal is input to the / A converter 21 and converted into an analog signal.
The analog signal converted by the D / A converter 20 is input to a monitor 22 and reproduced as a visible image.

On the other hand, the analog image signal converted by the D / A converter 21 is input to the developing unit 100 shown in FIG. The following processing is performed in the developing unit 100. An image signal output from the image processing unit 1B is an AO (not shown).
Transferred to M driver. The AOM driver drives the acousto-optic modulator (AOM) 104 of the image exposure unit 98 so as to modulate the light beam according to the transferred image information. On the other hand, the image exposure section 98 scans and exposes the photosensitive material A by light beam scanning (raster scan) to record an image of image information on the photosensitive material A. As shown in FIG. A light source 102R for emitting a light beam in a narrow band corresponding to the exposure of the R photosensitive layer formed on A, a light source 102G corresponding to the exposure of the G photosensitive layer, and a light source 102G corresponding to the exposure of the B photosensitive layer. A light source for each light beam of the light source 102B,
AOMs 104 R, 104 G and 104 B for modulating the light beams emitted from each light source in accordance with a recorded image, a polygon mirror 96 as an optical deflector, and an fθ lens 106;
A sub-scanning conveyance means 108 for the photosensitive material A is provided.

Each light beam emitted from the light source 102 (102R, 102G, 102B) and traveling at a different angle from each other is transmitted to the corresponding AOM 104 (104R, 104G, 102G).
104 B). As the light source 102, various light beam light sources capable of emitting a light beam of a predetermined wavelength corresponding to the photosensitive layer of the photosensitive material A can be used, and various semiconductor lasers, SHG lasers, He-Ne lasers, and the like can be used. A gas laser or the like is exemplified. A multiplexing optical system that multiplexes each light beam may be used. To each AOM 104, R, G, and B drive signals r, g, and b corresponding to the recorded image are transferred from the AOM driver, and the incident light beam is emphasized and modulated according to the recorded image.

Each light beam modulated by the AOM 104 enters a polygon mirror 96 as an optical deflector, is reflected, is deflected in the main scanning direction (the direction of the arrow x in the drawing), and then is scanned by the fθ lens 106 for a predetermined scan. The light is adjusted so as to form an image at a position z with a predetermined beam shape, and is incident on the photosensitive material A. In addition, the optical deflector is not only a polygon mirror,
It may be a resonant scanner, a galvanometer mirror, or the like. In addition, it is a matter of course that such an image exposure unit 98 may be provided with a light beam shaping unit and a surface tilt correction optical system as necessary.

On the other hand, the photosensitive material A is loaded at a predetermined position while being wound in a roll and shielded from light. The photosensitive material A is drawn out by a drawer such as a drawer roller, cut into a predetermined length by a cutter (not shown), and then a pair of rollers 108 arranged with a scanning position z constituting the sub-scanner 108 therebetween. By means of a and b, the sheet is conveyed in the sub-scanning direction (the direction of the arrow y in the drawing) substantially perpendicular to the main scanning direction while being held at the scanning position z. Here, since the light beam is deflected in the main scanning direction as described above,
The entire surface of the photosensitive material A conveyed in the sub-scanning direction is two-dimensionally scanned by a light beam, and an image of image information represented by an image signal processed by the LUT 19 is recorded. The photosensitive material A that has been exposed is then transported to a pair of transport rollers.
The printing is carried into the developing unit 100 by the developing unit 100 and subjected to a developing process to obtain a finished print P. Here, for example, photosensitive material A
Is a silver halide photographic light-sensitive material, the developing section 100 is composed of a color developing / developing tank 112, a bleaching / fixing tank 114, washing tanks 116a, 116b and 116c, a drying section 118 and the like. Is subjected to a predetermined process in the processing tank, and is output as a finished print P.

In the embodiment shown in FIG. 6, the light beam is modulated by the AOM 104. However, if the light source can directly modulate an LD or the like, the light beam can be modulated. May be modulated according to the recorded image. In addition, the sub-scanning conveyance means is not only two pairs of rollers arranged with the scanning position interposed therebetween, but also an exposure drum holding the photosensitive material at the scanning position and two nip rollers arranged with the scanning position interposed therebetween. Is also good.

Further, besides the light beam scanning described above,
A so-called drum scanner may be used in which a photosensitive material is wound around a drum, a light beam is incident on one point, and the drum is rotated and moved in the axial direction. In addition to the light beam scanning, surface exposure using a surface light source and a liquid crystal shutter may be used, or exposure using a linear light source such as an LED array may be used. In FIG. 6, the photosensitive material is cut into a sheet before exposure. However, the photosensitive material may be cut as it is before or after the developing unit 100 by exposing it as a roll.

As described above, the monitor 22 or the developing unit
The image reproduced as a visible image at 100 is shown in FIG.
In the backlit scene shown in (1), the human being, the subject, will not be lost in black, and the image of the bright background will not drop out. Further, even if the image is obtained by photographing using a strobe, the image can be reproduced without a nearby person or background being crushed.

When dodging is performed by controlling the luminance distribution of the illumination light source, there is no other way than to control the color reproducibility by selecting the MTX15 coefficient. In the part, the brightness and the color reproducibility change simultaneously, resulting in an unnatural print. However, since the MTX 15 converts a color signal into a light / dark signal, the brightness of the edge portion of the subject changes, but the color reproducibility does not change, so that a print with a natural finish can be obtained.
Further, since the LUTs 17 and 19 are non-linear, the non-linear parts of the characteristics of the original film (for example, the over part,
It is also possible to perform gradation correction of an under part or the like. Further, by adding a processing block for enhancing sharpness, local contrast of an image can be enhanced.

Further, it has been confirmed by experiments by the present applicant that most frames can be beautifully finished without changing the shape of the LUT for each frame. That is, in the γ setting of the LUT based on a scene with a high contrast, even if a scene with a normal or weak contrast is processed, if the size of the LPF is large, the blurred image signal has a flat shape. There is a property that it hardly occurs. As a result, in the case of the surface exposure system, it is necessary to largely correct the exposure time determined from the average density, for example, in accordance with the difference between the average density and the main subject density, in order to set the main subject to an appropriate finished density. However, in the method according to the present invention, a sufficiently good reproduced image can be obtained with a small correction.

Further, according to the first embodiment of the present invention, the image signal can be processed only by reading the image from the film 6 once without performing the pre-scan. Can be performed at high speed.

Next, the second embodiment of the image reproducing apparatus according to the present invention will be described.
An embodiment will be described.

FIG. 8 is a diagram showing a second embodiment of the image reproducing apparatus according to the present invention. As shown in FIG. 8, the image reproducing apparatus 1 according to the second embodiment of the present invention first performs a pre-scan for roughly reading an image recorded on the film 6 for each pixel at a predetermined interval, and obtains the pre-scan. The distance between pixels is reduced based on the information
To perform a fine scan for reading the image recorded in the. In addition, as compared with the image reproducing apparatus 1 according to the first embodiment of the present invention shown in FIG. 1, pre-scan frame memories 45R, 45G and 45B for storing signals obtained by pre-scan, The difference is that a dimming controller 43 for adjusting the dimming unit 3 based on the signal obtained by the above is provided and an interpolation means for interpolating the signal obtained by the prescan. In the second embodiment, an LPF 16a having a large mask size for monitor display for pre-scan is provided as an LPF 16 for blur mask generation as shown in FIG. The two low-pass filters, LPF 16b having a small mask size and LPF 16c having a large mask size for large-size printing, are connected in parallel so as to be selectively used by a selector 16d switched by a size input means 16e. Can be

At the time of pre-scan, the LPF 16a having a large monitor display mask size is used, and its output is input to the LUT 17 and sent to the monitor 40 at the same time.

At the time of fine scan, a low-pass filter having a mask size corresponding to the pixel density of an image to be reproduced is selected from the LPF 16b having a small mask size for small-size printing and the LPF 16c having a large mask size for large-size printing. An image signal is created and a dodging process is performed. The two low-pass filters are connected to a selector 16 operated by the size input means 16e.
Switched by d and used alternatively.

In the second embodiment of the present invention, a pre-scan is performed first. That is, the image reading unit 1A
The light source 2 emits light, and the dimming unit 3 converts the light into a predetermined amount of light, which is transmitted through an RGB filter 4. This light is diffused by the mirror box 5 to form a film 6.
Is irradiated. This light is modulated in accordance with an image recorded on the film 6 and is irradiated on the CCD 8 through the lens 7. At this time, the CCD 8 does not use all the pixels of the CCD 8 but photoelectrically detects the irradiated light using, for example, every other pixel. By switching the RGB filter 4 between R, G, and B, 3 representing a color image is displayed.
A color prescan signal is obtained and sent to the image processing unit 1B. The pre-scan signal is amplified by an amplifier 10 and then converted into a digital pre-scan signal in an A / D converter 11 and converted into a density signal by an LUT 12 to be used as a pre-scan frame memory 45R, 45G, 45B.
Respectively.

Next, the dimming controller 43 reads out the pre-scan signals stored in the pre-scan frame memories 45R, 45G, 45B, and adjusts the dimming unit 3 during fine scan based on the signal values of the pre-scan signals. Then, the light amount of the light emitted from the light source 2 is adjusted. That is, if the signal value obtained by the pre-scan is relatively large, the amount of light applied to the film 6 during the fine scan is made relatively small to prevent the density of the finally obtained image from becoming too high. If the signal value obtained by the pre-scan is relatively small, the amount of light applied to the film 6 during the fine scan is made relatively large, so that the density of the finally obtained image becomes too low. To prevent

When the light control section 3 is adjusted based on the pre-scan signal in this way, fine scanning is subsequently performed. In the fine scan, first, a light of a predetermined amount is emitted from the light source 2 of the image reading unit 1A, and the light of a predetermined amount is emitted by the light adjusting unit 3, as in the prescan. The predetermined light amount is determined based on a pre-scan signal obtained by the pre-scan. The light passes through the RGB filter 4, is diffused by the mirror box 5, and is irradiated on the film 6. The transmitted light of the film 6 modulated according to the image recorded on the film 6 is applied to a CCD 8 through a lens 7 and is photoelectrically converted into an image signal representing the image recorded on the film 6. At this time, unlike the pre-scanning, the light transmitted through the film 6 is photoelectrically detected using all the pixels of the CCD 8. By switching the RGB filter 4 between R, G, and B, three-color image signals representing a color image are obtained and sent to the image processing unit 1B. The image signal obtained in the image reading unit 1A is amplified by an amplifier 10 and then converted into a digital image signal by an A / D converter 11, converted into a density signal by an LUT 12, and stored in frame memories 13R, 13G and 13B, respectively. Is done. Next, the digital image signal is stored in the frame memory 13
R, 13G, and 13B are read out, color-corrected by the MTX 14, and input to the subtraction means 18.

On the other hand, the pre-scan signal is
The signals are read from 45R, 45G, and 45B, and converted into bright and dark signals by MTX15. Here, MTX15 is R as described above.
One third of the average value of each image signal of GB, or YIQ
A color image signal is converted into a light / dark signal using a rule or the like. The light / dark signal thus obtained is then converted into a blur mask signal by an LPF 16 optimal for the size (pixel density) of the reproduced image.
The tone is converted by T17. And between pixels by the interpolation means 42 has a one pixel interval is interpolated based on the pixel values of pixels adjacent to between the pixel, thereby blurring the image signals S _B are obtained. After that, the blurred image signal S
_B is input to the subtraction means 18.

As in the first embodiment, the digital image signal S _A is input to the subtraction means 18, while the signal S _A is copied and converted by the MTX 15 into a light / dark signal. MT
X15 is 3 of the average value of each image signal of RGB as described above.
A color image signal is converted into a light / dark signal by using a 1/1 or YIQ rule. The light-dark signal thus obtained is then converted into a blur mask signal by the LPF 16 optimal for the size (pixel density) of the reproduced image selected as described above. And this unsharp mask signal is gradation-converted by the LUT 17, thereby being converted into the unsharp image signals S _B. Then, the digital image signal S _A subtraction of the blurred image signal S _B is performed after the difference signal Ssub in the subtraction means 18 is obtained. The difference signal Ssub thus obtained is subjected to gradation conversion, density conversion, and the like by the LUT 19, and is input to the D / A converter 20 or the D / A converter 21 to be converted into an analog signal. The analog signal converted by the D / A converter 20 is input to a monitor 22 and reproduced as a visible image.

As described above in detail, in the image reproducing method and apparatus according to the present invention, in dodging processing, a plurality of types of low-pass filters for creating blurred images having different mask sizes are prepared, and the plurality of low-pass filters are prepared. A low-pass filter having a mask size corresponding to the pixel density of an image to be reproduced is selected from among various low-pass filters, and a dodging process is performed using a blurred image signal created using the selected low-pass filter. Therefore, even if the reproduced images have different sizes, the same dodging effect can always be obtained.

Further, by producing a blurred image signal based on the light / dark signal of the digital image signal, even if the brightness of the reproduced image (especially the edge portion of the subject) changes,
Since the color reproducibility does not change, an image without unnaturalness similar to the original color image can be reproduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of an image reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing γ characteristics of LUT17.

FIG. 3 is a diagram showing a γ characteristic of LUT19.

FIG. 4 is a diagram showing a low-pass filter.

FIG. 5 is a diagram for explaining processing performed in the image reproducing apparatus according to the present invention.

FIG. 6 is a diagram illustrating an embodiment of a developing unit.

FIG. 7 is a diagram illustrating a configuration of an LPF for generating a blur mask in the first embodiment of the image reproducing apparatus according to the present invention;

FIG. 8 is a diagram showing a second embodiment of the image reproducing apparatus according to the present invention.

FIG. 9 is a diagram illustrating a configuration of an LPF for generating a blur mask in the second embodiment of the image reproducing apparatus according to the present invention.

[Explanation of symbols]

2 light source 3 dimmer 4 RGB filter 5 mirror box 6 film 7 lens 8, 8A, 8B CCD 10, 10A, 10B amplifier 11, 11A, 11B A / D converter 12, 12, A, 12B, 17, 19 LUT 13R, 13G, 13B, 40R, 40G, 40B, 45R, 45G, 45
B frame memory 14, 15 MTX 16 Low-pass filter (LPF) 16a Low-pass filter for monitor display (LPF) 16b Low-pass filter for small-size printing (LP
F) 16c Low-pass filter for large size printing (LP
F) 16d selector 16e size input means 18 subtraction means 20, 21 D / A converter 22 monitor 100 developing unit

Claims (6)

[Claims] 1. An image reproducing method for reproducing a visible image from a digital image signal representing a photographic image, comprising: preparing a plurality of types of low-pass filters for creating blurred images having different mask sizes from the digital image signal; From among the plurality of types of low-pass filters, a low-pass filter having a mask size corresponding to the pixel density of the image to be reproduced is selected. Using the selected low-pass filter, a blur image signal representing a blur image of the photographic image The subtraction is performed between the signals of the pixels corresponding to the digital image signal and the blurred image signal to obtain a difference signal, and the difference signal is subjected to predetermined image processing and processed. An image reproducing method comprising: obtaining an image signal; and reproducing the processed image signal as a visible image. 2. The image reproducing method according to claim 1, wherein a suitable low-pass filter is selected from a plurality of types of low-pass filters having different mask sizes according to a print size to be reproduced. 3. An appropriate low-pass filter is selected from a plurality of types of low-pass filters having different mask sizes according to a print size to be reproduced and whether or not an image to be reproduced is a monitor display image. The image reproducing method according to claim 1, wherein 4. An image reproducing apparatus for reproducing a visible image from a digital image signal representing a photographic image, wherein: a plurality of types of low-pass filters for creating blurred images having different mask sizes from the digital image signal; Low-pass filter selecting means for selecting a low-pass filter having a mask size corresponding to the pixel density of the image to be reproduced from among the low-pass filters of the type; and using the selected low-pass filter to represent a blurred image of the photographic image Blur image signal creating means for creating a blur image signal; subtraction means for subtracting between the digital image signal and the blur image signal between signals of corresponding pixels to obtain a difference signal; Image processing means for performing predetermined image processing on the image signal to obtain a processed image signal, and using the processed image signal as a visible image An image reproducing apparatus, comprising: reproducing means for reproducing. 5. The image reproducing apparatus according to claim 4, wherein said low-pass filter selecting means selects an appropriate low-pass filter according to a print size to be reproduced. 6. The low-pass filter selecting means according to claim 4, wherein said low-pass filter selecting means selects an appropriate low-pass filter according to a print size to be reproduced and whether or not an image to be reproduced is a monitor display image. Image playback device.