JP2002027237A - Image data output device, image maker, and photograph processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image data output device which can perform processing at low cost and at high speed, in the constitution of performing interpolation to original image data. SOLUTION: An output image data generator is equipped with a buffer memory 26 which stores once a part of an inputted original image data, and an interpolation computing part 27 which generates the picture element data of an interpolating picture element by interpolating computation based on the original image data stored in the buffer memory 26. The interpolation computing part 27 is composed of simple digital circuits comprising, for example, an adder, a multiplier, etc., and this interpolation computing part 27 serially outputs the picture element data of an original image picture element and the picture element data of an interpolating picture element.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image data output apparatus, an image forming apparatus, and a photographic processing apparatus for performing interpolation processing on original image data.

[0002]

2. Description of the Related Art Conventionally, in printing a photograph, an analog exposure is performed in which a photographic film on which an original image is recorded is irradiated with light, and the light transmitted through the photographic film is irradiated on photographic paper to perform printing. ing. In recent years,
Based on digital image data obtained by reading an image on a photographic film with a scanner or digital image data obtained by photographing with a digital camera, monochromatic light of red, green, and blue is printed on photographic paper for each pixel. Digital exposure for printing by irradiation is performed.

Various types of digital exposure systems have been developed. Recently, a laser exposure printer that scans and exposes photographic paper while modulating a laser beam according to image data has been proposed. ing. The laser exposure printer having such a configuration includes a light source that generates laser light of each color of red, green, and blue, and performs a printing operation in the following procedure. First, laser light of each color is modulated based on input digital image data. Then, the modulated laser light is deflected in the main scanning direction by a deflector such as a polygon mirror, and is irradiated on photographic paper via an optical system such as an fθ lens. At the same time, the photographic printing paper is conveyed and moved in the sub-scanning direction to perform scanning exposure, and a two-dimensional color image is printed on the photographic printing paper.

[0004]

In the above-mentioned laser exposure printer, since laser light is continuously emitted in the main scanning direction, in a printed image on photographic paper, adjacent dots are all connected. Is burned in. That is, the main scanning line is formed by one continuous line. However,
In the sub-scanning direction, since exposure is discontinuously performed for each main scanning line, a gap may be generated between adjacent main scanning lines. Since such a gap becomes an unexposed portion, it is very conspicuous in a printed image, and causes a reduction in image quality.

Therefore, the resolution is set to 2 in the sub-scanning direction.
There has been proposed a configuration in which scanning exposure is performed at double the exposure. In this configuration, interpolation pixel data is generated by performing an interpolation operation on the original image data in the sub-scanning direction, and exposure is performed in a state where the number of main scanning lines is increased using the interpolation pixel data. By performing such exposure, the interval between adjacent main scanning lines is reduced, so that the above-described unexposed portions are eliminated, and the image quality of a printed image can be improved.

However, conventionally, as described above, only the problem of suppressing the occurrence of an unexposed area in the gap between the main scanning lines in the sub-scanning direction has been recognized, and improvement in resolution in the main scanning direction has been recognized. No specific scheme is disclosed.

For example, as a method for increasing the resolution, P
Perform image processing in C (Personal Computer) etc.
A configuration in which image data in a state where the number of pixels is increased is sent to a printer and printing is performed is conceivable. However,
In the case of such a configuration, the size of image data sent to the printer becomes large, so that it is necessary to increase the capacity of a memory for a data buffer provided in the printer, which causes a problem of increasing costs. ing.

In the printer, the same image processing as the above-described processing in the PC is performed on the input image data by, for example, a microprocessor or a DSP (Digital Signal Processor) to increase the number of pixels. It is also conceivable that the printing is performed by using. However, also in this case, there is a problem that a memory for storing image data whose size has been increased by performing the image processing is required, which causes an increase in cost. Needless to say, there is also a problem that the cost is significantly increased by providing a microprocessor or a DSP.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an image processing apparatus capable of performing an inexpensive and high-speed image processing in a configuration in which interpolation processing is performed on original image data. An object of the present invention is to provide a data output device, an image forming device, and a photographic processing device.

[0010]

According to a first aspect of the present invention, there is provided an image data output apparatus, comprising: performing an interpolation process on input original image data;
An image data output device that outputs output image data with an increased number of pixels, a buffer memory that temporarily stores a part of the original image data, and based on the original image data stored in the buffer memory. An interpolation operation unit that generates pixel data of the interpolation pixel by an interpolation operation, wherein the interpolation operation unit includes an adder and a multiplier that serially outputs the pixel data of the original image pixel and the pixel data of the interpolation pixel. It is characterized by being constituted by a digital circuit.

In the above configuration, the interpolation operation section for generating the pixel data of the interpolation pixel by the interpolation operation based on the original image data stored in the buffer memory is constituted by a digital circuit having an adder and a multiplier. Have been. Therefore, it is possible to provide a device that performs the interpolation processing at low cost without using an expensive device such as a microprocessor or a DSP.

Further, since the interpolation operation section is constituted by a digital circuit having an adder and a multiplier for serially outputting the pixel data of the original image pixel and the pixel data of the interpolation pixel, the interpolation operation section stores the pixel data in the buffer memory. The original image data to be stored only needs to include data including pixels related to the interpolation calculation of the interpolation pixel to be interpolated. Therefore, the storage capacity of the buffer memory can be significantly reduced as compared with a configuration in which image data for one image needs to be stored, for example. Therefore, the cost of the apparatus can be reduced.

According to a second aspect of the present invention, there is provided the image data output device according to the first aspect, wherein the interpolation operation section calculates the pixel data of the interpolated pixel using only the adder.

According to the above configuration, the interpolation operation processing performed in the interpolation operation section can be realized by a hardware digital circuit having an extremely simple structure called an adder. Therefore, the increase in the cost of the apparatus can be kept extremely small, and the processing time required for the interpolation calculation can be made very short.

According to a third aspect of the present invention, the image forming apparatus scans by irradiating the photosensitive material with a laser beam modulated in synchronization with a pixel clock in accordance with image information while relatively moving the photosensitive material. In an image forming apparatus that performs exposure, a buffer memory that temporarily stores a part of input original image data, and pixel data of an interpolation pixel is generated by an interpolation operation based on the original image data stored in the buffer memory. And performing an exposure based on the original image data at least every other pixel clock in the exposure in the main scanning direction, and performing an exposure based on the pixel data of the interpolated pixel in a clock during the exposure in the main scanning direction. Features.

In the above configuration, the image processing apparatus includes the interpolation operation unit that generates the pixel data of the interpolation pixel by the interpolation operation based on the original image data stored in the buffer memory. The exposure based on the original image data is performed at intervals, and the exposure based on the interpolated pixel data is performed at the pixel clock during the exposure. That is, according to such a configuration, when the number of pixels in the main scanning direction increases by performing the interpolation processing, the number of pixels can be easily increased by increasing the pixel clock. Therefore, it is possible to easily and inexpensively cope with an increase in the number of pixels in the main scanning direction due to the interpolation processing.

The image forming apparatus according to the fourth aspect is the third aspect.
In the configuration described above, the interpolation calculation unit generates the pixel data of the interpolation pixel by interpolation calculation based on the original image data on both sides of the interpolation pixel, and performs the exposure in the main scanning direction at every other clock of the pixel clock. In addition, the exposure based on the original image data is performed, and the exposure based on the pixel data of the interpolated pixel is performed in a clock during the exposure.

According to the above configuration, since the interpolation calculation unit generates the pixel data of the interpolation pixel by the interpolation calculation based on the original image data on both sides of the interpolation pixel, the interpolation calculation unit generates the pixel data required for the interpolation calculation. Only two image data are required. Therefore, the configuration required for the calculation can be simplified, and the calculation time can be shortened. Further, since the storage capacity of the buffer memory for temporarily storing the original image data can be reduced, the cost of the apparatus can be reduced.

According to the fifth aspect of the present invention, there is provided the image forming apparatus according to the fourth aspect.
In the configuration described above, the interpolation calculation unit generates the pixel data of the interpolation pixel by an interpolation calculation based on the density difference between the original image data on both sides of the interpolation pixel.

In the above configuration, the interpolation calculation unit generates the pixel data of the interpolation pixel by the interpolation calculation based on the density difference between the original image data on both sides of the interpolation pixel. Therefore, for example, when the density difference between the original image data on both sides of the interpolation pixel is large, the pixel data of the interpolation pixel is set to a value close to either of the original image data, and the density difference between the original image data on both sides of the interpolation pixel is If it is small, the pixel data of the interpolated pixel is made to be about the middle value of the density of the original image data on both sides, and thereby the gradual change in density and the edge part in the original image are preserved. This makes it possible to output an image.

According to a sixth aspect of the present invention, there is provided the image forming apparatus according to the fourth aspect.
Alternatively, in the configuration described in 5, the interpolation calculation unit generates the pixel data of the interpolation pixel as an average value of the original image data on both sides of the interpolation pixel.

In the above configuration, the interpolation calculation unit generates the pixel data of the interpolation pixel as an average value of the original image data on both sides of the interpolation pixel. Therefore, for example, in the case where interpolation processing is performed on an area in which the density gradually changes in the original image, it is possible to output an image in which the density is gradually changed.

The image forming apparatus according to a seventh aspect is the fourth aspect.
Alternatively, in the configuration described in 5, the interpolation calculation unit generates the pixel data of the interpolation pixel as the same value as one of the original image data on both sides of the interpolation pixel.

In the above configuration, the interpolation calculation unit generates the pixel data of the interpolation pixel as the same value as one of the original image data on both sides of the interpolation pixel. Therefore, for example, in the case where interpolation processing is performed on an edge region in which the density is rapidly changed in the original image, an image in which the edge portion is stored can be output.

The photographic processing apparatus according to the eighth aspect is the third aspect of the present invention.
An image forming apparatus according to any one of claims 1 to 7, a developing section for developing the photosensitive material printed by the image forming apparatus by using a developing solution, and a developing process in the developing section. And a drying unit for drying the light-sensitive material.

According to the above configuration, the printing, developing, and drying processes for the photosensitive material can be performed continuously under centralized management, so that a large amount of operation can be performed without imposing a burden on the user in operation. Photos can be printed continuously.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

The photographic processing apparatus according to the present embodiment prints on a photosensitive material based on image data of an original image,
This is a digital photographic printer that prints an original image on a photosensitive material by performing development and drying processes.

FIG. 2 is an explanatory diagram showing the configuration of the above-mentioned photographic processing apparatus. As shown in FIG. 2, the photographic processing apparatus includes an exposure unit 1, a photographic paper storage unit 2, a development unit 3, a drying unit 4, and a PC (Personal Computer) 5.

The photographic paper storage unit 2 stores photographic paper, which is a photosensitive material, and supplies the photographic paper to the exposure unit 1 during printing. The exposure unit 1 prints an image by subjecting the photographic paper supplied from the photographic paper storage unit 2 to scanning exposure according to the image data of the original image. Details of the exposure unit 1 will be described later.

The developing section 3 develops an image by transporting the photographic paper subjected to the printing process while applying various developing solutions. The drying unit 4
This is for drying the photographic paper subjected to the development processing. The PC 5 functions as a man-machine interface between the photo processing apparatus and an operator, and instructs a processing operation in the photo processing apparatus and displays a processing status.

The processing of the photographic processing apparatus itself is controlled by
This is performed by a CPU provided in the photo processing device.
Various data processing performed on the input image data is performed by image processing dedicated hardware provided in the photo processing apparatus.

Next, the configuration of the exposure unit 1 will be described. FIG. 3 is an explanatory diagram illustrating the configuration of the exposure unit 1 and the photographic paper storage unit 2. As shown in FIG. 3, the photographic paper storage unit 2 located above the exposure unit 1 includes two paper magazines 2a and 2b for storing roll-shaped photographic paper P. Each of the paper magazines 2a and 2b stores photographic paper P of a different size, and is set so that the photographic paper P to be supplied can be switched according to the size of the output image desired by the user. The exposure unit 1 is provided with the photographic paper P supplied from the photographic paper storage unit 2 as described above.
, And is provided with a printing unit (image forming apparatus) 6 and transport rollers R1 to R5.

The printing section 6 irradiates light for exposure to the photographic paper P being transported by the transport rollers R1 to R5. The transport rollers R1 to R5 feed the photographic paper P supplied from the photographic paper storage unit 2 to the developing unit 3 via the printing unit 6.

Next, the configuration of the printing section 6 will be described. FIG. 4 is an explanatory diagram illustrating a schematic configuration of the printing unit 6. The printing unit 6 includes a light source unit 7R, 7G, 7B, a scanning unit 8, and a transport unit 9.

(Structure of Light Source Unit) The light source unit 7R includes a red LD.
(Laser Diode) (light source) 10R, lens group 11R, acousto-optic modulator (AOM: Acousto-Optic Modulator)
(Light beam modulating means) 12R, dimming unit 13R, and mirror 14R. Lens group 11R, AOM12
The R and the dimmer 13R are arranged in this order on the optical axis from the red LD 10R to the mirror 14R.

The red LD 10R is a semiconductor laser that emits laser light having a wavelength of a red component. The lens group 11
R is a lens group for shaping the red laser light emitted from the red LD 10 and guiding the red laser light to the light entrance of the next AOM 12R.

The AOM 12R is an optical modulator using a so-called acousto-optic diffraction, which is a diffraction phenomenon in which a refractive index distribution created in a transparent medium by a sound wave acts as a phase diffraction grating, and changes the intensity of an applied ultrasonic wave. This modulates the intensity of the diffracted light. This A
An AOM driver 15R is connected to the OM 12R, and a high-frequency signal whose amplitude is modulated according to image data is input from the AOM driver 15R.

For the AOM 12R, the AOM driver 1
When a high-frequency signal is input from 5R, an ultrasonic wave according to the high-frequency signal is propagated in the acousto-optic medium. When laser light passes through such an acousto-optic medium, diffraction occurs due to the effect of the acousto-optic effect, and laser light having an intensity corresponding to the amplitude of the high-frequency signal is emitted from the AOM 12R as diffracted light.

The light control section 13R is a member for adjusting the overall intensity of the laser light emitted from the AOM 12R and modulated in accordance with image data, and includes, for example, an ND filter or a plurality of openings having different sizes. It is constituted by a provided rotating plate and the like. Light emitting elements such as semiconductor lasers and solid-state lasers have a fixed light amount range in which light can be emitted in a stable state. By adjusting the overall light amount by the light control unit 13R, the color development characteristics of photographic paper can be improved. Exposure can be performed in a light amount range that provides a correspondingly wide dynamic range.

The mirror 14R reflects the laser beam emitted from the light control section 13R in the direction in which the scanning section 8 is arranged. This mirror 14R outputs
Any mirror that reflects the red component light may be used. In the present embodiment, since a red laser beam having only the wavelength of the red component is incident on the mirror 14R, a mirror that totally reflects the incident light is used as the mirror 14R.

On the other hand, the light source 7G is provided with a green SHG (Second
Harmonic Generation) Laser unit (light source) 10G,
An AOM (light beam modulator) 12G, a dimming unit 13G, and a dichroic mirror 14G are provided. AOM
12G and the dimmer 13G are arranged in this order on the optical axis from the green SHG laser unit 10G to the dichroic mirror 14G.

The green SHG laser unit 10G functions as a light source for emitting laser light having a green component wavelength. Inside the green SHG laser unit 10G, although not shown, a solid-state laser such as a YAG laser and a second-harmonic generation unit for extracting a second harmonic from laser light emitted from the solid-state laser are provided. A variable wavelength unit and the like are provided. For example, YA
When a laser beam having a wavelength of 1064 nm is emitted from the G laser, a laser beam having a wavelength of 532 nm (green component) is generated in the second harmonic generation unit, and the laser beam having the second harmonic component is emitted. Will be. In the configuration of the present embodiment, a solid-state laser is used as a unit that emits a basic laser beam. However, the present invention is not limited to this. For example, an LD may be used.

In the light source section 7R, the red LD 1
While a lens group 11R is provided between 0R and AOM 12R, such a lens group is not provided in the light source unit 7G. However, the lens group 11R
A configuration having a function equivalent to that of the green SHG laser unit 10G is provided inside the green SHG laser unit 10G.

The AOM 12G and the light control section 13G have the same configuration as the AOM 12R and the light control section 13R described in the light source section 7R. That is, AOM1
2G modulates the laser light emitted from the green SHG laser unit 10G according to the image data, and the dimmer 13G adjusts the overall light amount of the laser light emitted from the AOM 12G. .

The dichroic mirror 14G is connected to the dimming unit 1
The laser light of the green component emitted from 3G is reflected in the direction in which the scanning unit 8 is arranged. The dichroic mirror 14G has a property of reflecting only light of a wavelength of a green component and transmitting light of other wavelengths.
The dichroic mirror 14G is connected to the light source 7R.
Are arranged on the optical path from the mirror 14R to the scanning unit 8 at the point. The red laser light reflected by the mirror 14R passes through the dichroic mirror 14G and reaches the scanning unit 8. That is, the light traveling from the dichroic mirror 14G toward the scanning unit 8 is composed of a red component laser beam and a green component laser beam modulated according to image data.

The light source section 7B has substantially the same configuration as the light source section 7G, and includes a blue SHG laser unit (light source) 10B, an AOM (light beam modulating means) 12B, a dimming section 13B, and a dichroic mirror 14B. It has. The AOM 12B and the light control section 13B
G laser unit 10B to dichroic mirror 14
B are arranged in this order on the optical axis reaching B.

The blue SHG laser unit 10B functions as a light source for emitting laser light having a wavelength of a blue component, and has substantially the same configuration as the green SHG laser unit 10G. The AOM 12B and the dimming unit 13B are the same as those of the AOM described in the light source units 7R and 7G.
It has the same configuration as the 12R / 12G and the dimmers 13R / 13G. That is, the AOM 12B has a blue S
The laser light emitted from the HG laser unit 10B is modulated according to image data.
Is for adjusting the overall light amount of the laser light emitted from the AOM 12B.

The dichroic mirror 14 B
The laser beam of the blue component emitted from 3B is reflected in the direction in which the scanning unit 8 is arranged. The dichroic mirror 14G has a property of reflecting only light having a blue component wavelength and transmitting light having other wavelengths.
The dichroic mirror 14B is a mirror 14
The red laser light that is disposed on the optical path from the R and dichroic mirror 14G to the scanning unit 8 and that is reflected by the mirror 14R and transmitted through the dichroic mirror 14G, and the green laser light that is reflected by the dichroic mirror 14G , Dichroic mirror 14
The light passes through B and reaches the scanning unit 8. That is, the light traveling from the dichroic mirror 14B toward the scanning unit 8 is composed of red, green, and blue component laser beams modulated according to image data.

In the present embodiment, as described above, AOM is used as a configuration for modulating the intensity of laser light of each color component.
Although 12R, 12B, and 12G are used, the present invention is not limited to this. For example, an electro-optic modulator (EO)
M), and a configuration that modulates the intensity of the laser beam by applying a magneto-optical modulator (MOM) or the like.

(Structure of Scanning Unit) The scanning unit 8 includes a reflecting mirror 16, a cylindrical lens 17, a polygon mirror (deflecting means) 18, and an fθ lens (optical means) 20. A cylindrical lens 17 is arranged on an optical axis extending from the reflection mirror 16 to the polygon mirror 18, and an fθ lens 20 is arranged on an optical path extending from the polygon mirror 18 to the printing paper P.

The reflection mirror 16 includes a light source section 7R, 7G, 7
Mirror 14R and dichroic mirror 14G in B
A member that reflects the red, green, and blue component laser beams reflected at 14B in the direction in which the polygon mirror 18 is disposed.

The cylindrical lens 17 is a lens that condenses the laser light reflected by the reflection mirror 16 on the reflection surface of the polygon mirror 18 in the sub scanning direction. The cylindrical lens 17 performs correction (surface tilt correction) when a surface tilt error (an error in which the normal direction of the reflective surface deviates from the normal direction of the normal main scanning surface) occurs on the reflective surface of the polygon mirror 18. To do.

If a tilt error occurs on the reflection surface of the polygon mirror 18, the arrival position of the laser beam on the photographic paper P changes greatly, and pitch unevenness occurs in the printed image. In the present embodiment, as described above, the light is temporarily condensed by the cylindrical lens 17 on the reflection surface of the polygon mirror 18 in the sub-scanning direction, and the laser light reflected from the polygon mirror 18 is fθ
The fθ lens 20 and the photographic paper P are arranged so as to converge on the photographic paper P again after passing through the lens 20. With such an arrangement, the reflection surface of the polygon mirror 18 and the photographic paper P are optically conjugate to each other, so that even if the light beam is deflected in the sub-scanning direction due to the surface tilt, the photographic paper P
The light flux forms an image at the same position above. In other words, even if light is emitted from a point on the reflection surface of the polygon mirror 18 in any direction within a certain range, an image is formed at the same position on the printing paper P.

The polygon mirror 18 is a rotator provided so that a plurality of reflection surfaces form a regular polygon, and is driven to rotate by a polygon driver 19. The laser light emitted from the reflection mirror 16 via the cylindrical lens 17 is reflected by one reflection surface of the polygon mirror 18 and travels in the photographic paper P direction. The direction of reflection of the laser light from the polygon mirror 18 moves in the main scanning direction according to the rotation of the polygon mirror 18. When the reflection of the laser beam on one reflection surface is completed by the rotation of the polygon mirror 18, the irradiation of the laser beam is shifted to the reflection surface adjacent to the reflection surface, and the reflection direction of the laser beam is shifted in the main scanning direction in the same range. Moving. As described above, one scanning line is scanned by one reflecting surface, and the next scanning line is scanned by an adjacent reflecting surface. Therefore, a time lag between adjacent scanning lines in the sub-scanning direction is extremely reduced. It is possible to make it smaller.

The fθ lens 20 is an optical system for correcting image distortion near both ends of the scanning surface due to the laser light emitted from the polygon mirror 18 to the printing paper P, and is composed of a plurality of lenses. . The image distortion near both ends of the scanning plane is caused by the difference in the length of the optical path from the polygon mirror 18 to the printing paper P.

The synchronous sensor 21 is located outside the main scanning range of the laser beam from the polygon mirror 18 to the printing paper P.
A and a mirror 21B are provided. Mirror 21
B is disposed at a position just outside the direction in which the main scanning starts as viewed from the polygon mirror 18. In other words, the laser light reflected from one reflection surface of the polygon mirror 18 first strikes the mirror 21B,
Immediately thereafter, exposure on the photographic paper P in the main scanning direction is performed.

The direction of the reflection surface of the mirror 21B is set such that the laser light from the polygon mirror 18 is irradiated on the synchronous sensor 21A. The length of the optical path from the polygon mirror 18 to the synchronization sensor 21A via the mirror 21B is
Is designed to be approximately equal to the length of the optical path from the point of view to the starting point of the main scanning on the photographic paper P.

The synchronous sensor 21A is a sensor for detecting light, and when a laser beam is irradiated from the polygon mirror 18 via the mirror 21B, a signal is transmitted to a control unit (not shown) at the irradiation timing. That is, by monitoring the output from the synchronous sensor 21A, the printing paper P
The above-mentioned scanning timing can be accurately grasped.

(Construction of Conveying Section) The conveying section 9 is provided with a conveying roller 22, a micro step motor 23, a micro step driver 24 and the like. The transport roller 22 is a roller that transports the photographic paper P, and in FIG. 4, transports the photographic paper P in a direction perpendicular to the paper surface.

The micro step motor 23 is a motor for driving the transport roller 22, and is constituted by a micro step motor which is a kind of a stepping motor. This micro step motor is a motor that can control the rotation angle extremely precisely.

The micro-step driver 24 drives the rotation of the micro-step motor 23. Under the control of a control unit (not shown), the sub-scanning of the printing paper P is adjusted so as to match the resolution of the output image in the sub-scanning direction. The transport speed in the direction is controlled.

As described above, the printing unit 6 according to the present embodiment includes the red, green,
The photographic paper P is exposed while the laser light corresponding to each of the blue colors is moved in the main scanning direction, and the photographic paper P is transported in the sub-scanning direction, so that a two-dimensional printed image is printed on the photographic paper P. It is configured to be formed.

Next, an output image data generation unit (image data output device) 25 for generating output image data in which interpolation pixel data obtained by an interpolation operation is added to the original image data sent from the PC 5 will be described. I do. The output image data generation unit 25 is provided in the printing unit 6 in the present embodiment, but is not limited to this. Data output from the PC 5 to each of the above-described AOM drivers in the printing unit 6 is not limited to this. It may be provided at any position on the communication path.

FIG. 1 is a block diagram showing a schematic configuration of the output image data generator 25. As shown in the figure,
The output image data generation unit 25 includes a buffer memory 26,
And an interpolation operation unit 27. The interpolation calculator 27 includes a main scanning interpolation calculator 28, a sub-scanning interpolation calculator 29, a main / sub-scanning interpolation calculator 30, and an original image data output unit 31. The original image data sent from the PC 5 is first input to the buffer memory 26, and an operation is performed in the interpolation operation unit 27. After that, the image data output from the output image data generation unit 25 is sent to a not-shown LUT (Look Up Table) to be γ-corrected and converted to analog data by a D / A converter (not shown). Sent to the driver. Note that the output image data generation unit 25 shown in FIG. 1 is configured to double the number of pixels in the main scanning direction and the number of pixels in the sub-scanning direction by performing an interpolation operation on the original image data.

The buffer memory 26 is a memory for temporarily buffering the original image data sent from the PC 5. In the present embodiment, the capacity of the buffer memory 26 is such that pixel data of two rows of pixel rows in the main scanning direction in the original image can be stored for each of the RGB color components.

FIG. 5 is an explanatory diagram schematically showing a storage area of one color component in the buffer memory 26. FIG.
, The storage area of one color component in the buffer memory 26 is (X _m , Y _n ) (m = 1, 2, 3,...)
The configuration is such that data of each pixel is stored at an address indicated by (n = 1, 2). The original image data is input to the buffer memory 26 for each of the pixel rows in the main scanning direction, and is buffered for two rows. Then, the data is sequentially erased from the memory as the interpolation operation proceeds, and data of a new pixel row is buffered. In FIG. 5, each pixel data A ₁₁ ,
, A ₂₁ , A ₃₁ , ..., A ₁₂ , A ₂₂ , A ₃₂ , ... are stored (stored) at respective addresses of the buffer memory 26.

FIG. 6 is an explanatory diagram schematically showing a two-dimensional array of image data to which interpolation pixels have been added by the interpolation calculation unit 27 based on the image data stored in the buffer memory 26. 5, the original image pixel data A ₁₁ , A ₂₁ , A ₃₁ ,..., A ₁₂ , A ₂₂ , A ₃₂ ,... Of two columns in the main scanning direction stored in the buffer memory 26 in FIG.
... on the basis of the interpolated pixel data _{a 11, a 21, ...,} b 11,
The state of the image data to which b ₂₁ ,..., c ₁₁ , c ₂₁ ,.

As shown in FIG. 6, the interpolation pixel data a ₁₁ ,
a ₂₁ ,... are original image pixel data A ₁₁ , A ₂₁ ,.
, And the interpolation pixel data b
_11, b _21, ... are each original image pixel data A _11,
A _21, ... are adjacent in the sub-scanning direction lower side of the interpolation pixel data c _11, c _21, ... are each interpolated pixel data a _11, a _21, ... in the sub-scanning direction lower side, another way That is, it is assumed that the interpolation pixel data b ₁₁ , b ₂₁ ,... Are adjacent to the right side in the main scanning direction.

The interpolated pixel data a ₁₁ , a ₂₁ ,... Are data obtained by an interpolating operation based on two original image pixel data adjacent in the main scanning direction. Is performed by the main-scanning interpolation calculator 28. Interpolated pixel data b ₁₁ , b ₂₁ ,
Are data obtained by an interpolation operation based on two original image pixel data that are adjacent to each other in the sub-scanning direction. This interpolation operation is performed by the sub-scanning interpolation operation unit 29 in the interpolation operation unit 27. Further, the interpolated pixel data c ₁₁ , c ₂₁ ,... Are data obtained by an interpolative operation based on four original image pixel data which are obliquely adjacent to each other. -This is performed by the sub-scanning interpolation calculator 30.

Hereinafter, a specific method for obtaining each interpolated pixel data will be described. First, the interpolation pixel data a ₁₁ ,
Regarding a ₂₁ ,..., the interpolation calculation in the main scanning interpolation calculator 28 will be described.

The main scanning interpolation arithmetic unit 28 designates an address in the buffer memory 26 from the original image pixel data stored in the buffer memory 26, thereby converting the adjacent original image pixel data in the main scanning direction. By taking in, interpolation calculation is performed. For example, FIG.
In the state shown in, the interpolation pixel data a ₁₁ is determined by the following interpolation. a ₁₁ = (A ₁₁ + A ₂₁ ) / 2 (1) With respect to the other interpolated pixel data a ₂₁ ,..., based on two original image pixel data adjacent in the main scanning direction, the following equation (1) is used. A value is calculated by performing a similar linear interpolation operation. A configuration for processing such an interpolation operation is, for example, an adder 32 shown in FIG.
It can be realized by.

In the example shown in FIG. 10, it is assumed that the image data is composed of 8-bit data. That is, the adder 32 is an adder that outputs 9-bit data by adding two 8-bit data. Here, the output of each bit of the 9-bit output data by the adder 32 is represented by OUT (0) to OUT (0).
(8). Of the 9-bit output data, the lowest one bit, that is, the output of OUT (0) is discarded, and the upper eight bits, that is, OUT (1) to OUT (0) are discarded.
(8), when output as bit data of the interpolated pixel data a _11, so that the calculation of the above equation (1) is performed.

That is, the interpolation arithmetic processing shown in the equation (1) can be realized by a hardware digital circuit having an extremely simple configuration as shown in FIG. 10, that is, an adder. Therefore, the increase in the cost of the apparatus can be kept extremely small, and the processing time required for the interpolation calculation can be made very short.

In the above-mentioned interpolation calculation, the linear interpolation calculation as shown in the equation (1) is performed. However, the invention is not limited to this. For example, the interpolation calculation according to the following equation may be performed. It is possible. a ₁₁ = αA ₁₁ + (1−α) A ₂₁ (0 ≦ α ≦ 1) (2) Such an interpolation operation can be configured by a simple hardware digital circuit including an adder and a multiplier. It is.

In the above description, the interpolation operation is performed based on two original image pixel data adjacent in the main scanning direction. However, the interpolation operation is performed by further adding the adjacent original image pixel data. Is also good. For example, in the original image,
The pixel data of the further to the left pixel of the pixels of the A ₁₁ When A ₀₁ (although not shown in FIG. 5), the interpolated pixel data a ₁₁ may be determined as follows. a ₁₁ = (A ₀₁ + 2A ₁₁ + 2A ₂₁ + A ₃₁ ) / 6 (3) By performing the interpolation operation as in the above equation (3), it is possible to obtain interpolated pixel data reflecting data of a wider range of pixels. Therefore, the output image can be made more natural.
However, to perform the interpolation operation as in the expression (3), the circuit becomes complicated, and the difference between the image quality and the output image based on the interpolation operation in the expression (1) is not so large. Therefore, in practice, it can be said that an interpolation operation based on two original image pixel data is sufficient.

The sub-scanning interpolation calculator 29 designates an address in the buffer memory 26 from the original image pixel data stored in the buffer memory 26, thereby converting the adjacent original image pixel data in the sub-scanning direction. By taking in, interpolation calculation is performed. For example, FIG.
In the state shown in, the interpolation pixel data b ₁₁ is determined by the following interpolation. b ₁₁ = (A ₁₁ + A ₁₂ ) / 2 (4) With respect to the other interpolated pixel data b ₂₁ ,..., based on two original image pixel data adjacent in the sub-scanning direction, A value is calculated by performing a similar linear interpolation operation. Such an interpolation operation can be configured by an adder having a simple configuration as shown in FIG.

In the above-described interpolation operation, a linear interpolation operation as shown in the equation (4) is performed. However, the present invention is not limited to this. For example, an interpolation operation using the following equation may be performed. It is possible. b ₁₁ = αA ₁₁ + (1−α) A ₁₂ (0 ≦ α ≦ 1) (5) Such an interpolation operation can be configured by a simple hardware digital circuit including an adder and a multiplier. It is.

In the above description, the interpolation operation is performed based on two original image pixel data adjacent in the main scanning direction. However, the interpolation operation is performed by further adding the adjacent original image pixel data. Is also good. For example, in the original image,
The pixel data of the further upper neighboring pixels of the pixel of the A ₁₁ A _10, A
₁₂ pixels further pixel data of the lower adjacent pixels of When A ₁₃ (although not shown in FIG. 5), the interpolated pixel data a ₁₁ may be determined as follows. b ₁₁ = (A ₁₀ + 2A ₁₁ + 2A ₁₂ + A ₁₃ ) / 6 (6) By performing the interpolation calculation as in the above equation (6), it is possible to obtain interpolated pixel data reflecting data of a wider range of pixels. Therefore, the output image can be made more natural.
However, performing the interpolation operation as shown in the expression (6) complicates the circuit, and the buffer memory 26
In this case, it is necessary to store two more pixel rows in the main scanning direction of the original image pixel data, which causes a problem of an increase in cost due to an increase in the storage capacity of the buffer memory. Also, an output image obtained by such an interpolation operation,
Since the difference in image quality between the output image and the output image based on the interpolation operation based on Expression (4) is not so large, it can be said that the interpolation operation based on the two original image pixel data is practically sufficient.

The main / sub-scanning interpolation calculator 30 calculates the original image pixel data stored in the buffer memory 26 from the original image pixel data.
The interpolation calculation is performed by taking in the four original image pixel data adjacent in the oblique direction by designating the address in the buffer memory 26. For example, in the state shown in FIG. 6, the interpolation pixel data c ₁₁ is
It is obtained by the following interpolation calculation. _{c 11 = (a 11 + a} 12) / 2 = ((A 11 + A 21) / 2 + (A 12 + A 22) / 2) / 2 = (A 11 + A 21 + A 12 + A 22) / 4 (7) above ( 7), the interpolation pixel data c ₁₁ has become a calculated assuming that linear interpolation of the interpolated pixel data a ₁₁ · a ₁₂ adjacent to and below in the sub-scanning direction. Even if the interpolation pixel data c ₁₁ is calculated as a result of linearly interpolating the interpolation pixel data b ₁₁ and b ₂₁ adjacent to the left and right in the main scanning direction, the equation becomes the same as the equation (7).

The values of the other interpolated pixel data c ₂₁ ,... Are calculated by performing a linear interpolation operation similar to the equation (7) based on the four original image pixel data adjacent to each other in the oblique direction. Will do. Such an interpolation operation can be realized by adding four 8-bit data in the adder 32 shown in FIG. 10 to constitute an adder that outputs 10-bit data. That is, among the 10-bit output data, discarding the output of the lower 2 bits, the output of the upper 8 bits, if the output as the bit data of the interpolation pixel data c _11, the calculation of the equation (7) is carried out Will be.

That is, the interpolation arithmetic processing shown in the equation (7) can be realized by a hardware digital circuit having an extremely simple configuration, that is, an adder, similar to the configuration shown in FIG. Therefore, the increase in the cost of the apparatus can be extremely small, and
The processing time required for the interpolation operation can be extremely short.

In the above-mentioned interpolation calculation, the linear interpolation calculation as shown in the equation (7) is performed. However, the invention is not limited to this. For example, the interpolation calculation using the following equation may be performed. It is possible. c ₁₁ = αa ₁₁ + (1-α) a ₁₂ = β (αA ₁₁ + (1-α) A ₂₁ ) + (1-β) (αA ₁₂ + (1-α) A ₂₂ )) / 2 (8 (0 ≦ α ≦ 1, 0 ≦ β ≦ 1) Such an interpolation operation can be configured by a simple hardware digital circuit including an adder and a multiplier.

In the above description, the interpolation operation is performed on the basis of the four original image pixel data adjacent in the oblique direction. An interpolation operation may be performed. By performing such an interpolation operation, it is possible to obtain interpolated pixel data reflecting data of a wider range of pixels.
The output image can be made more natural. However, to perform such an interpolation operation, the circuit becomes extremely complicated, and in the buffer memory 26,
It becomes necessary to store more original image pixel data, which causes a problem of an increase in cost due to an increase in the storage capacity of the buffer memory. In addition, since the difference in image quality between the output image based on the interpolation operation and the output image based on the interpolation operation based on the equation (7) is not so large, in practice, the four elements which are obliquely adjacent to each other are used. It can be said that an interpolation operation based on image pixel data is sufficient.

The original image data output unit 31 is a block for directly outputting the original image data stored in the buffer memory 26. That is, the original image data output unit 31 outputs the original image pixel data A ₁₁ , A ₂₁ , A shown in FIG.
_{31, ..., A 12, A} 22, A 32, thereby outputting ....

The main scanning interpolation calculator 2 having the above configuration
8, sub-scanning interpolation calculator 29, main / sub-scanning interpolation calculator 3
The trigger signal is input to the 0 and the original image data output device 31 at the timing corresponding to each of them, and the interpolation calculation and the data output are respectively performed based on the timing of the trigger signal. This allows
The image data as shown in FIG. 6 is serially output from the output image data generator 25 to each AOM driver.

In the above description, the interpolation operation for the image data of one color component has been described. By performing the same operation for the image data of the other color components, the output image data generator 25 The RGB color image data subjected to the interpolation processing is output.

As described above, according to the output image data generating unit 25 having the above configuration, the interpolation operation for increasing the number of pixels in the main scanning direction and the sub-scanning direction is performed by a simple digital hardware. This can be performed by a circuit. Thus, for example, a microprocessor or D
The cost of the apparatus can be significantly reduced as compared with a configuration in which interpolation calculation is performed by SP or the like.

Also, for the input original image data,
Since the interpolation calculation processing can be performed at high speed by the calculation by hardware, the delay of the processing speed due to the interpolation calculation can be minimized.

Further, the buffer memory 26 in the output image data generation section 25 only needs to have a capacity capable of storing two pixel rows in the main scanning direction. Therefore, for example, a memory that can store all of the image data of the original image is required, or a memory that can store all of the image data including the interpolation pixel data is required. The cost of the device can be kept low.

In the above description, as shown in FIG. 6, the interpolation pixels are generated such that the number of pixels is doubled in each of the main scanning direction and the sub-scanning direction. However, the present invention is not limited to this. . For example, the interpolation calculation unit 27 may be configured to include only the main-scan interpolation calculator 28, and may be configured to generate interpolation pixels such that the number of pixels is doubled only in the main-scan direction. Similarly, the interpolation calculation unit 27 may be configured to include only the sub-scanning interpolation calculation unit 29, and may be configured to generate interpolation pixels such that the number of pixels is doubled only in the sub-scanning direction.

Further, the configuration may be such that the interpolation pixels are generated such that the number of pixels is three times or more in the main scanning direction and / or the sub-scanning direction. FIG. 7 shows the state of the pixels of the output image when the interpolation pixels are generated such that the number of pixels is tripled in each of the main scanning direction and the sub-scanning direction. As shown in the figure, for example, two interpolation pixels d ₁₁ and e ₁₁ are provided between the original image pixel data A ₁₁ and the original image pixel data A ₂₁ adjacent in the main scanning direction. The interpolation pixels d ₁₁ and e ₁₁ are obtained by, for example, the following calculation. d ₁₁ = (2/3) A ₁₁ + (1/3) A ₂₁ (9) e ₁₁ = (1/3) A ₁₁ + (2/3) A ₂₁ (10) Also, original image pixel data A ₁₁ And the interpolated pixel f ₁₁ · i ₁₁ provided between the original image pixel data A ₁₂ and the original image pixel data A ₁₂ adjacent thereto in the sub-scanning direction can also be obtained by performing the same linear interpolation calculation as the equations (9) and (10). Further, the interpolation pixel g
₁₁ , h ₁₁ , j ₁₁ , and k ₁₁ are also obtained by appropriately performing a linear interpolation operation based on the surrounding pixel data.

The values of other interpolated pixel data d ₂₁ ,... Are calculated by performing the same linear interpolation operation. Such an interpolation operation can be configured by a simple hardware digital circuit including an adder and a multiplier. However, the number of interpolation calculators increases in proportion to the increase in the number of interpolation pixels.

In the above interpolation calculation, (9) (1
Although the linear interpolation calculation as shown in the equation (0) is performed, the invention is not limited to this. For example, the interpolation calculation by the following equation can be performed. d ₁₁ = βA ₁₁ + (1-β) A ₂₁ (0 ≦ β ≦ 1) (11) e ₁₁ = (1-β) A ₁₁ + βA ₂₁ (0 ≦ β ≦ 1) (12) Although the interpolation calculation is performed based on two original image pixel data adjacent in the main scanning direction,
Further, an interpolation operation may be performed by adding the adjacent original image pixel data. In this case, it is possible to obtain interpolated pixel data reflecting data of a wider range of pixels, so that an output image can be made more natural. However,
In order to perform such an interpolation operation, the circuit becomes significantly complicated, and it is necessary to store more original image pixel data in the buffer memory 26, which increases the cost due to an increase in the storage capacity of the buffer memory. This will cause problems. In addition, since the difference in image quality between the output image based on the interpolation operation and the output image based on the interpolation operation based on the equations (9) and (10) is not so large, the equations (9) and (10) are practically used. It can be said that the interpolation calculation by the above is sufficient.

In the example shown in FIG. 7, a state is shown in which the number of pixels in the main scanning direction and the number of pixels in the sub-scanning direction are each tripled. However, the present invention is not limited to such interpolation. Alternatively, an interpolation operation for increasing the number of pixels at different magnifications in the main scanning direction and the sub-scanning direction may be performed.

Next, the printing operation performed by the printing unit 6 shown in FIG. 4 based on the output image data in which the number of pixels has been increased by performing the above-described interpolation calculation will be described. First, when the number of pixels increases in the main scanning direction, AOM
AOM12R ・ 1 from driver 15R ・ 15G ・ 15B
This is dealt with by increasing the pixel clock of the data input to each of the 2G and 12B in proportion to the increase rate of the number of pixels. For example, when an interpolation operation for doubling the number of pixels in the main scanning direction is performed, the pixel clock is set to 2
By increasing the number twice, the number of pixels projected on one main scanning line can be doubled, and high resolution can be achieved.

[0097] The case where the number of pixels increases in the main scanning direction is not limited to the above-described method. For example, the rotation speed of the polygon mirror 18 is reduced. The method may be used.

When the number of pixels is increased in the sub-scanning direction, the problem is dealt with by reducing the transport speed of the photographic paper P in the transport section 9. For example, when an interpolation operation for doubling the number of pixels in the sub-scanning direction is performed,
By reducing the transport speed of the photographic paper P to １ ／, the interval between pixels in the sub-scanning direction can be reduced to 、, and high resolution can be achieved.

The case where the number of pixels increases in the sub-scanning direction is not limited to the above-described method. For example, the pixel clock is increased and the rotation speed of the polygon mirror 18 is increased. Quicker,
It is also possible to cope with such a method.

Next, the preservation of edges in output image data in which the number of pixels has been increased by performing an interpolation operation will be described. For example, in an image region including a human face and a distant mountain, a change in density between adjacent pixels is relatively small. Even if the above-described interpolation calculation is performed on such an image area, the change in the image quality is slight.

On the other hand, in an image region such as a boundary region between a human and a background and an outline portion of a building or the like, the density of adjacent pixels often changes rapidly. When the above-described interpolation calculation is performed on such an image area, an interpolation pixel having an intermediate density is inserted between a high-density pixel and an adjacent low-density pixel. , The edges will be blurred.

Therefore, the output image data generating section 25 in the present embodiment generates output image data in which edges are preserved by performing the following interpolation processing. First, the interpolation processing in the main scanning interpolation calculator 28 will be described with reference to the flowchart shown in FIG.

First, in step 1 (hereinafter abbreviated as S1), it is necessary to perform an interpolation operation on the original image pixel data adjacent to the target interpolation pixel in the main scanning direction, that is, the target interpolation pixel. Are obtained from the buffer memory 26. Next, in S2, a density difference Δd between the above two original image pixel data obtained from the buffer memory 26 is obtained.

If the density difference Δd is equal to or larger than the predetermined value k (YES in S3), the pixel data of the interpolation pixel is set to the same value as one of the two original image pixel data. (S4). On the other hand, if the density difference Δd is smaller than the predetermined value k (NO in S3), the above-described interpolation calculation is performed based on the two original image pixel data, thereby obtaining the pixel of the interpolation pixel. Data is set (S5). Such interpolation pixel data setting processing is performed for all interpolation pixels (S
6).

In the above S4, as a method of setting the value of the pixel data of the interpolation pixel to the same value as one of the two original image pixel data, for example, the following method can be considered. First, as a value of pixel data of an interpolation pixel, a method of setting a value on the left side (or right side) of the interpolation pixel of the two original image pixel data can be considered. Similarly, as the value of the pixel data of the interpolation pixel,
There is also a method of setting the value of the darker (or lighter) of the two original image pixel data. The former method tends to be an image closer to the original image image, and the latter method tends to be an image that emphasizes dark parts (or bright parts).

In the above-described interpolation processing, the pixel data of the interpolated pixel is set to the same value as one of the two original image pixel data in accordance with the density difference between the two original image pixel data. The value is obtained by interpolation. However, it is possible to preserve edges by a method different from this processing. For example, a method is conceivable in which all the interpolated pixels are obtained by an interpolation operation, and the coefficients of the interpolation operation are changed according to the density difference between the two original image pixel data.

More specifically, for example, in the above equation (2), a value obtained by multiplying two original image pixel data by a coefficient α ((1−α)) is the interpolation pixel data. However, there is a method of setting this coefficient as a function of the density difference between two original image pixel data. That is, for example, when the density difference is small, the value of α is 1 /
If the density difference is close to 2 and the density difference is large, the edge can be preserved by setting the value of α to a function that is far from 1/2.

In the above, the interpolation processing in the main scanning interpolation calculator 28 has been described with reference to the flowchart shown in FIG. 8. However, substantially the same processing is performed by the sub-scanning interpolation calculator 29 and the main / sub-scanning interpolation. By performing the calculation in the arithmetic unit 30 as well, it is possible to perform the interpolation processing in which the edges are preserved for the interpolation pixels in the sub-scanning direction and the main and sub-scanning directions (oblique directions).

Here, specific examples of the interpolation processing based on the flowchart shown in FIG. 8 will be described with reference to FIGS. 9 (a) and 9 (b).
It will be described based on. FIG. 9A shows an example of a part of the original image pixel data, and FIG. 9B shows the example of FIG.
5 shows the state of pixel data of an output image obtained by performing an interpolation process on.

In FIG. 9A, the density of the pixels p1 to p4 is gradually increased in this order, the density of the pixel p5 is significantly reduced, and the density of the pixel P6 is again increased. ing. That is, it is assumed that a large density difference Δd is generated between the pixel p4 and the pixel p5 and between the pixel p5 and the pixel p6, and the density difference Δd is larger than the predetermined value k.

For such original image pixel data, interpolation pixels s1 to s5 are inserted between the pixels p1 to p6, respectively. At this time, the interpolation pixels s1 to s inserted between the pixels p1 to p4 in which the density difference Δd is smaller than the predetermined value k.
3 passes through the NO path in S3 in FIG.
A value is set by performing the process of S5, that is, by performing an interpolation operation. Therefore, in the region from the pixel p1 to the pixel p4, the change in density is in a smooth state.

On the other hand, the interpolation pixel s4 inserted between the pixel p4 and the pixel p5 whose density difference Δd is larger than the predetermined value k.
Passes through the YES path in S3 in FIG.
The process of S4, that is, the same value as one of the two original image pixel data is set. In the example shown in FIG. 9B, the interpolation pixel s4 is set to have the same density as the pixel p4.

Similarly, the interpolation pixel s5 inserted between the pixel p5 and the pixel p6 whose density difference Δd is larger than the predetermined value k passes through the path of YES in S3 in FIG. That is, it is set as the same value as one of the two original image pixel data. FIG. 9B
In the example shown in (1), the interpolation pixel s5 is set to have the same density as the pixel p5.

As described above, in the original image shown in FIG. 9A, the area of the pixels p1 to p4 whose density changes gradually is subjected to the interpolation processing as shown in FIG. This preserves the gradual concentration. Also,
At the same time, in the original image shown in FIG. 9A, the edge regions between the pixels p4 and p5 and between the pixels p5 and p6 are as shown in FIG. 9B. Then, the edge is preserved even after the interpolation processing.

As described above, if the interpolation processing as shown in the flowchart of FIG. 8 is performed, the image data in which the edges are stored is output without performing complicated image processing such as applying a filter for edge enhancement. be able to. Therefore, an expensive structure for performing complicated image processing can be eliminated, and the cost of the apparatus can be reduced.

Note that the interpolation processing of the flowchart shown in FIG. 8 is actually performed for each of the RGB color components, but the density difference Δd in S2 and S3 is RG
A case where a density difference of the density obtained by averaging the data of each of the B color components is used, and a case where a density difference for each data of each of the RGB color components is used.

When the density difference of the average density of each of the RGB color components is used as the density difference Δd, the density difference Δd in S3 is used.
It is needless to say that whether or not is equal to or more than the predetermined value k is the same for all the RGB colors. In this case, since the edge detection is performed based on the average density, there is not much change in the density, but an image area in which the hue changes rapidly is not detected as an edge.

On the other hand, when the density difference between the data of each of the RGB color components is used as the density difference Δd,
Whether the density difference Δd is equal to or greater than the predetermined value k is determined by RG
B will be different for each color component. At this time, the determination in S3 is that Y is determined for at least one of the color components.
If ES, the process of S4 is performed for all color components. According to such processing, even in an image region where the density does not change much but the hue changes rapidly, it is possible to detect this as an edge and store the edge.

[0119]

As described above, the image data output apparatus according to the first aspect of the present invention performs an interpolation process on input original image data to output output image data with an increased number of pixels. A buffer memory for temporarily storing a part of the original image data, and generating pixel data of an interpolated pixel by an interpolation operation based on the original image data stored in the buffer memory. And a digital circuit that includes an adder and a multiplier that serially outputs the pixel data of the original image pixel and the pixel data of the interpolated pixel.

As a result, it is possible to provide an inexpensive device for performing the interpolation processing without using expensive devices such as a microprocessor and a DSP.

The original image data to be stored in the buffer memory only needs to include the data including the pixels involved in the interpolation calculation of the interpolation pixel to be interpolated. Is, for example, compared to a configuration that requires storing image data for one image,
It can be much smaller. Therefore, there is an effect that the cost of the apparatus can be reduced.

An image data output device according to a second aspect of the present invention is configured such that the interpolation calculation section calculates pixel data of an interpolation pixel using only an adder.

Thus, in addition to the effect of the configuration of claim 1, it is possible to minimize the increase in the cost of the apparatus and to reduce the processing time required for the interpolation calculation. It works.

The image forming apparatus according to the third aspect of the present invention moves the photosensitive material relative to the image forming apparatus in accordance with the image information.
In an image forming apparatus that performs scanning exposure by irradiating the photosensitive material with laser light modulated in synchronization with a pixel clock, a buffer memory that temporarily stores a part of input original image data, An interpolating operation unit that generates pixel data of an interpolated pixel by an interpolation operation based on the stored original image data, and performs exposure in the main scanning direction based on the original image data at least every other pixel clock. In this configuration, the exposure is performed, and the exposure based on the pixel data of the interpolation pixel is performed in the clock during the exposure.

Thus, when the number of pixels in the main scanning direction increases by performing the interpolation processing, the number of pixels can be easily increased by increasing the cycle of the pixel clock. It is possible to easily and inexpensively cope with an increase in the number of pixels in the scanning direction.

According to a fourth aspect of the present invention, in the image forming apparatus, the interpolation operation section generates the pixel data of the interpolation pixel by the interpolation operation based on the original image data on both sides of the interpolation pixel and in the main scanning direction. In this exposure, the exposure based on the original image data is performed every other clock of the pixel clock, and the exposure based on the pixel data of the interpolated pixel is performed in the intervening clock.

Thus, in addition to the effect of the configuration of claim 3, only two pieces of original image data are required for the interpolation operation, so that the configuration required for the operation can be simplified and the operation time can be reduced. Is also shortened. Further, since the storage capacity of the buffer memory for temporarily storing the original image data can be reduced, there is an effect that the apparatus cost can be reduced.

According to a fifth aspect of the present invention, in the image forming apparatus, the interpolation calculation unit generates the pixel data of the interpolation pixel by the interpolation calculation based on the density difference between the original image data on both sides of the interpolation pixel. .

Thus, in addition to the effect of the configuration of claim 4, for example, when the density difference between the original image data on both sides of the interpolation pixel is large, the pixel data of the interpolation pixel is close to one of the original image data. If the density difference between the original image data on both sides of the interpolated pixel is small, the pixel data of the interpolated pixel is set to about the intermediate value of the densities of the original image data on both sides. There is an effect that it is possible to output an image in which a portion having a gradual change in density and an edge portion in the image are stored.

An image forming apparatus according to a sixth aspect of the present invention is configured such that the interpolation calculation section generates pixel data of an interpolation pixel as an average value of original image data on both sides of the interpolation pixel.

Thus, in addition to the effect of the configuration of claim 4 or 5, for example, when interpolation processing is performed on an area where the density gradually changes in the original image, the density change There is an effect that an image in which gradualness is preserved can be output.

An image forming apparatus according to a seventh aspect of the present invention is configured such that the interpolation operation section generates the pixel data of the interpolation pixel as the same value as one of the original image data on both sides of the interpolation pixel. .

Accordingly, in addition to the effect of the structure of claim 4 or 5, for example, when an interpolation process is performed on an edge region where the density is sharply changed in the original image, the edge portion is reduced. There is an effect that the stored image can be output.

According to an eighth aspect of the present invention, there is provided a photographic processing apparatus using the image forming apparatus according to any one of the third to seventh aspects and a photosensitive material baked by the image forming apparatus using a developing solution. The developing unit includes a developing unit that performs a developing process, and a drying unit that dries the photosensitive material that has been subjected to the developing process in the developing unit.

As a result, the printing, developing, and drying processes for the photosensitive material can be performed continuously under centralized control, so that a large number of photographs can be continuously printed without imposing an operational burden on the user. It can be printed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an output image data generation unit included in a photographic processing device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a schematic configuration of the photographic processing apparatus.

FIG. 3 is a side sectional view showing a schematic configuration of an exposure unit provided in the photographic processing apparatus.

FIG. 4 is an explanatory diagram showing a schematic configuration of a printing unit provided in the exposure unit.

FIG. 5 is an explanatory diagram schematically showing a storage area of one color component of a buffer memory provided in the output image data generation unit.

FIG. 6 is an explanatory diagram schematically showing a two-dimensional array of image data to which interpolation pixels have been added by an interpolation calculation unit based on the image data stored in the buffer memory.

FIG. 7 is an explanatory diagram showing states of pixels of an output image in a case where interpolation pixels are generated such that the number of pixels is tripled in each of a main scanning direction and a sub-scanning direction.

FIG. 8 is a flowchart showing a flow of an interpolation process in a main scanning interpolation calculator.

9A shows an example of a part of original image pixel data, and FIG. 9B shows pixel data of an output image obtained by performing an interpolation process on FIG. 9A. It is explanatory drawing which shows the state.

FIG. 10 is an explanatory diagram showing a schematic configuration of an adder.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Exposure unit 2 Photo paper storage unit 3 Developing unit 4 Drying unit 5 PC 6 Printing unit (image forming apparatus) 7R, 7G, 7B Light source unit 8 Scanning unit 9 Transport unit 10R, 10G, 10B Red LD, green SHG laser unit Blue SHG laser unit 12R, 12G, 12B AOM 14R mirror 14G, 14B Dichroic mirror 15R, 15G, 15B AOM driver 16 Reflection mirror 17 Cylindrical lens 18 Polygon mirror 19 Polygon driver 20 fθ lens 21A Synchronous sensor 21B Mirror 22 Micro-transport roller 23 Motor 24 Micro step driver 25 Output image data generation unit (image data output device) 26 Buffer memory 27 Interpolation operation unit 28 Main scanning interpolation operation unit 29 Sub scanning interpolation operation unit 30 Main / sub scanning interpolation operation unit 1-way image data output unit 32 adder

Claims (8)

[Claims] An image data output device for outputting output image data having an increased number of pixels by performing an interpolation process on input original image data, the image data output device comprising: A buffer memory for storing, based on the original image data stored in the buffer memory, an interpolation operation unit that generates pixel data of the interpolated pixel by an interpolation operation, wherein the interpolation operation unit An image data output device comprising a digital circuit having an adder and / or a multiplier for serially outputting data and pixel data of an interpolation pixel. 2. The image data output device according to claim 1, wherein said interpolation calculation section calculates pixel data of the interpolation pixel using only an adder. 3. An image forming apparatus for performing scanning exposure by irradiating a laser beam modulated in synchronization with a pixel clock in accordance with image information while relatively moving a photosensitive material, thereby performing scanning exposure. A buffer memory that temporarily stores a part of the input original image data, and an interpolation operation unit that generates pixel data of an interpolation pixel by an interpolation operation based on the original image data stored in the buffer memory. An image forming apparatus comprising: performing exposure based on original image data at least every other pixel clock in exposure in a main scanning direction; and performing exposure based on pixel data of an interpolated pixel in a clock between the clocks. 4. The interpolating operation unit generates pixel data of an interpolated pixel by an interpolating operation based on original image data on both sides of the interpolated pixel. 4. The image forming apparatus according to claim 3, wherein the exposure based on the original image data is performed, and the exposure based on the pixel data of the interpolated pixel is performed in a clock during the exposure. 5. The interpolating unit according to claim 4, wherein the interpolating unit generates the pixel data of the interpolated pixel by an interpolating operation based on a density difference between original image data on both sides of the interpolated pixel.
The image forming apparatus as described in the above. 6. The image forming apparatus according to claim 4, wherein said interpolation calculation unit generates pixel data of the interpolation pixel as an average value of original image data on both sides of the interpolation pixel. 7. The image according to claim 4, wherein the interpolation calculation unit generates the pixel data of the interpolation pixel as the same value as one of the original image data on both sides of the interpolation pixel. Forming equipment. 8. An image forming apparatus according to claim 3, further comprising: a developing section for developing the photosensitive material which has been printed by said image forming apparatus by using a developing solution. A photographic processing apparatus comprising: a drying unit for drying the photosensitive material that has been subjected to the development processing in the development processing unit.