JPH0451010B2 - - Google Patents

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to an arithmetic device.

[Conventional technology]

Conventionally, calculations are performed based on various signals in order to remove distortions contained in the signals and to perform various correction processes on the signals. A specific example of such calculations is correction of color signals.

In color recording devices and color display devices,
It is necessary to correct the input color signal by converting it into a desired color signal due to distortion of the read color signal at the image input unit or deviation from the ideal color characteristics of the recording medium or display medium. For example, in color laser beam printers and color inkjet printers, toner and ink do not have ideal spectral reflectance distribution characteristics for the primary colors cyan, magenta, and yellow, so color correction is not performed on the input signal. When a color image is recorded, only an extremely low-quality image with a hue different from the intended one can be obtained.

Conventionally, the desired output color signal was obtained by arithmetic processing of the input color signal using an electric circuit, but this method has a slow processing speed, so it is difficult to process the input color signal when the number of pixels is large. It takes a long time, and if advanced color correction processing is attempted, the processing time becomes even longer and the electric circuit for the processing becomes complicated.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, it is an object of the present invention to provide a device that can perform calculations at high speed with a relatively simple configuration.

[Summary of the invention]

The above object of the present invention is to perform the following matrix operation, when n and m are integers of 2 or more. The unit strength and the above-mentioned S ₁ , S ₂ ,...
..., S _o , each of which is arranged in a predetermined direction, and each of the
n grating-type electro-optic light modulators that diffract light beams with intensities corresponding to S ₁ , S ₂ , ..., S _o and emit each light beam at different angles in a direction perpendicular to the predetermined direction. and the a ₁₁ ,..., a _oo and b ₁₁ ,...
..., an optical filter in which parts exhibiting a transmittance corresponding to the absolute value of b _on are arranged in a matrix in a predetermined direction and in a direction perpendicular to the predetermined direction, and transmit the light from the optical modulator; A plurality of photodetectors are arranged in a matrix corresponding to each part, and the output of each photodetector is added or subtracted to correspond to the above-mentioned S ₁ ′, S ₂ ′, ..., S _o ′. This is achieved by comprising an arithmetic circuit that obtains an electrical signal.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings. Note that the embodiment will describe color correction calculations.

FIG. 1 is a block diagram of a color image recording apparatus incorporating a color correction device of the present invention. In the figure,
1 is an input section, 5 is a color correction section, that is, a color correction device according to the present invention, and 9 is an output section. In the input section 1, a color original is read by an image sensor such as a CCD. The light receiving section of the image sensor is equipped with filters for the primary colors cyan, magenta, and yellow, and a color signal (electrical signal) is obtained from this, and the input section 1 performs preprocessing such as log conversion. A cyan signal (hereinafter referred to as "C signal") 2, a magenta signal (hereinafter referred to as "M signal") 3, and a yellow signal (hereinafter referred to as "Y signal") 4 are output to the color correction unit 5. urge The color correction section 5 performs the following calculations, and outputs a corrected cyan signal (hereinafter referred to as "C'signal") 6 and a corrected magenta signal (hereinafter referred to as "M'signal") to the output section 9. (abbreviated as "signal")
7, and a corrected yellow signal (hereinafter abbreviated as "Y'signal") 8 is output.

C'=a ₀₀ C+a ₀₁ M+a ₀₂ Y+b ₀₀ C ² +b ₀₁ M ² +
b ₀₂ Y ² +b ₀₃ CM+b ₀₄ MY+b ₀₅ YC+g ₀ (C,
M, Y) M′=a ₁₀ C+a ₁₁ M+a ₁₂ Y+b ₁₀ C ² +b ₁₁ M ² +
b ₁₂ Y ² +b ₁₃ CM+b ₁₄ MY+b ₁₅ YC+g ₁ (C,
M, Y) Y′=a ₂₀ C+a ₂₁ M+a ₂₂ Y+b ₂₀ C ²
+b ₂₁ M ² +b ₂₂ Y ² +b ₂₃ CM+b ₂₄ MY+b ₂₅
YC + g ₂ (C, M, Y) [Here, g _i (C, M, Y) (i = 1, 2, 3)
is a third-order or higher-order term for C, M, and/or Y.] However, except for advanced color correction processing, g _i (C,
M, Y) are excluded. Also, the coefficient a ₀₀ ~
a ₂₂ and b ₀₀ to b ₂₅ can take either positive or negative values, but
For convenience of explanation below, both of these are assumed to be positive.

FIG. 2 is a diagram showing the operating principle of an electro-optical (hereinafter abbreviated as "E/O") modulation element used in the apparatus of the present invention. In the figure, 11 is a laser beam, 10 is a power source for light source intensity modulation of the laser light source 11, 13 is an E/O element, and 14 is a comb-shaped electrode formed on the E/O element 13. 15 is a power source for E/O effect modulation for applying voltage to the comb-shaped electrode 14;
7 is an ND filter, and 18 is a light receiving element.

Now, suppose b ₀₃ to find C′ in the above formula
Consider the case of calculating the CM terms. C to light source 10
By inputting a signal, the voltage applied to the laser light source is controlled, and the laser light source 1
A laser beam 12 with an intensity proportional to the C signal is made incident on the E/O element 13. On the other hand, power supply 1
By inputting the M signal to 5, the voltage applied to the comb-shaped electrode 14 is controlled, and the E/
An E/O effect proportional to the M signal is produced in the O element. As a result, the intensity of the light beam diffracted by the E/O effect within the E/O element 13 becomes proportional to the M signal. Therefore, the diffracted outgoing beam 16 from the E/O element 13 has an intensity proportional to the product (CM) of the C signal and the M signal. On the other hand, the filter 17 is given a transmittance corresponding to the coefficient b ₀₃ in the above equation. The emitted light beam 16 from the E/O element is passed through the filter 17 to the light receiving element 18.
When the light beam is made incident on the light receiving element 18, a light beam having an intensity proportional to b ₀₃ CM will be incident on the light receiving element 18. Thus, the light receiving element 18 outputs the signal b ₀₃ CM.

Similarly, the power supplies 10 and 15 are respectively inputted with one of the C, M and Y signals (unit signals), and the transmittance of the filter 17 is determined by the coefficients a ₀₀ to a ₂₂ and b ₀₀ to b of the above formula. By appropriately selecting one of ₂₅ and making it correspond to this, the light receiving element 18 is made to output signals of each of the first and second terms in the above equation.

FIG. 3 is a perspective view showing another aspect of E/O modulation used in the device of the present invention. In this embodiment, a plurality of light beams are transmitted as the incident beam 12 in a vertical plane (i.e., the comb-shaped electrode 1 in FIG.
A plurality of light beams are emitted from the E/O element 13 at different angles of incidence in a plane perpendicular to the pitch direction I got it as 16. Here, as shown in the figure, four light fluxes with intensities proportional to the I, C, M, and Y signals are used as the incident light flux 12, and the E/I obtained by the horsetail electrode 14 is used.
If the strength of the O effect is made proportional to the signal A input to the electrode 15, the output luminous flux 16 will be A, CA,
Four luminous fluxes proportional to MA and YA are obtained simultaneously. Here, if a C, M, or Y signal is used as the signal A, it is possible to obtain signals of each of the first-order and second-order terms in the above equation.

FIG. 4 is a perspective view showing another aspect of E/O modulation used in the device of the present invention. In this embodiment, a multiplexed light beam of laser beams of different wavelengths is used as the incident light beam 12. That is, laser beams of four different wavelengths are
The incident light beam 12 is obtained by modulating the C, M, and Y signals to intensities proportional to them and superimposing them. Since the laser beams of each wavelength have different diffraction angles within the E/O element 13, an emitted light beam 16 consisting of four light beams having different emission angles in the horizontal plane is obtained. Comb-shaped electrode 14
By making the intensity of the E/O effect obtained by the above similar to the case of FIG. 3, each of the emitted light beams 16 becomes proportional to A, CA, MA, and YA. Therefore, as in the case of FIG. 3, 1 in the above formula
Signals of the following and quadratic terms can be obtained.

FIG. 5 is a partial schematic perspective view for explaining the operation of the apparatus of the present invention. In this embodiment, an E/O modulation element 13' having three E/O modulation elements arranged in parallel as shown in FIG. 3 is used. That is, the E/O element 13' has three comb-shaped electrodes 1.
4a, 14b and 14c are provided, and a C signal, an M signal and a Y signal are respectively input to the power supply for each electrode. Therefore, when the incident light beam 12 consisting of four light beams is made incident on the E/O element 13', the output light beams 16a, 16b and 16c is emitted.

In FIG. 5, 17 is an ND filter. FIG. 6 is a distribution diagram of the light flux incident on the ND filter 17, which is observed from the right side in FIG. 5. Each beam has an intensity proportional to the value shown. Moreover, FIG. 7 is a plan view of the ND filter 17, which is observed from the right side in FIG. 5. The filter 1
7 is divided into 12 parts in a matrix, and the light transmittance of each part is proportional to some of the coefficients of the above equation as shown. Note that this filter 17 is for obtaining the C' signal. Furthermore, as can be seen from FIG. 6, among the light fluxes incident on the filter 17, two light fluxes proportional to the crossterms CM, MY, and YC appear redundantly, so the filter 17 corresponds to one of them. Position (indicated by the shaded area in Figure 7)
is shaded from light.

In Figure 5, 18-1, 18-2,...1
Reference numeral 8-12 denotes a light receiving element, which is arranged at a position corresponding to one of the matrix element parts of the ND filter 17, so that the light beam transmitted through the ND filter 17 is directed to the corresponding light receiving element for each matrix element part. incident. As mentioned above, since the filter 17 is partially shielded from light, the light receiving elements 18-7 and 18-1 in FIG.
0 and 18-11 are actually unnecessary. FIG. 8 is a distribution diagram of the luminous flux immediately after passing through the ND filter 17, that is, immediately before entering the light receiving element, and is observed from the right side in FIG. Each beam has an intensity proportional to the value shown.

Here, it is assumed that among the coefficients in the above equation, b ₀₁ , b ₀₄ and b ₀₅ are given negative signs. Light receiving element 18-
The outputs of the light receiving elements 1, 18-2, 18-3, 18-4, 18-5 and 18-12 are added by an adder 19a, while the outputs of the light receiving elements 18-6, 18-8 and 18
The outputs of -9 are added by an adder 19b, and the outputs of these adders 19a and 19b are inputted to an adder 20 with opposite signs and subtracted, so that from the adder 20, a ₀₀ C+a ₀₁ M+a ₀₂ Y+
b ₀₂ C ² −b ₀₁ M ² +b ₀₂ Y ² +b ₀₃ CM−b ₀₄ MY−b ₀₅ YC
An output color signal of =C' is obtained.

Similarly, the light transmittance of each matrix element portion of the filter 17 is changed and each light receiving element and adder 1
By appropriately setting connections with 9a and 19b and performing signal processing, an M' output color signal and a Y' output color signal can be obtained.

FIG. 9 is a partial plan view of a filter in another embodiment of the color correction apparatus of the present invention. In the above embodiments, the C', M', and Y' signals are obtained separately, but in this embodiment, these output color signals are obtained simultaneously.

That is, in the apparatus of this embodiment, instead of the filter 17 shown in FIG. 5 as shown in FIG.
The one shown in the figure is used. In this filter, the portion corresponding to each matrix element portion in FIG. All the coefficients up to the quadratic term for C, M and/or Y in the above equation are related to the light transmittance of the divided portion. One light-receiving element is arranged behind each of these divided portions, and receives the light transmitted through the filter. Coefficient a _0i (i=0,
1, 2) and b _0j (j = 0, 1, ... 5) from the light-receiving elements behind the filter divided portions are processed in the same manner as in the above embodiment to obtain the C' signal. Similarly, by processing the output signals from the light-receiving elements behind the filter division portion corresponding to coefficients a _1i and b _1j , as well as a _2i and b _2j , the M' signal and the Y' signal can be obtained at the same time. be able to.

In the embodiment shown in FIG. 5, the incident light beam 12
Four light beams proportional to the I, C, M, and Y signals are made incident at different angles of incidence, and three of the E/O elements are
The four comb-shaped electrodes produce an E/O effect proportional to the C, M, and Y signals, but conversely, four comb-shaped electrodes are provided in the E/O element, and these produce the I, C, M, and Y signals. C, M, and Y as the incident light flux 12 and producing an E/O effect proportional to the Y signal
A similar operation can be obtained by making three light beams proportional to the signal enter at different angles of incidence.

Further, in the embodiment of FIG. 5, a similar operation can be obtained by using a multiplexed light beam as in the embodiment of FIG. 4 as the incident light beam 12.

In addition, by arranging E/O elements in series in multiple stages as shown in FIG. 3 or 4, the above formula can be
It is also possible to perform calculations that include terms of higher order than third order regarding CM and/or Y. At this time, the grating pitch direction of each E/O modulation element can be set as appropriate depending on the direction in which the output light beam is taken out.

Furthermore, by using means such as additionally using a spatial light modulator, giving the light modulator a light transmittance based on a color signal, setting the optical path of each light beam appropriately, and using an appropriate filter, it is possible to Color correction including the term can also be performed in a similar manner.

The above description has been made regarding calculations for color correction, but the method and apparatus of the present invention can be applied not only to calculations for color correction but also to various calculations; for example, they can be applied to calculations for edge enhancement in image reading. can. In the calculation for edge enhancement, if the input signal intensity of a given pixel in an image is y and the input signal intensities of pixels on both sides adjacent to the pixel are x and z, the edge-enhanced output of the pixel is In order to obtain the signal y', the following calculation is performed.

y'=y+d(ax+by+cz) ³ =y+a ³ dx ³ +b ³ dy ³ +c ³ dz ³ +6abcdxyz +3a ² bdx ² y+3ab ² dxy ² +3b ² cdy ² z +3bc ² dyz ² +3c ² adz ² x+3ca ² dzx ² This is i.e. , is to perform an operation that adds a correction term d(ax+by+cz) ³ to the input signal y at the pixel, and it is generally known that this produces an edge-enhanced output signal with less noise and an edge-emphasized degree determined by the coefficient d. Well known (usually a=c=-1, b=2). Therefore,
In the present invention, an edge-enhanced output signal y' can be obtained by processing the three light fluxes having intensities corresponding to x, y, and z in the same manner as described in the color correction calculation above. . When the same calculation is performed for all pixels, as shown in FIG. 10, an output image having an edge-enhanced intensity A' is obtained from the intensity distribution A of each pixel in the input image.

[Effects of the Invention] According to the present invention as described above, since calculations are performed using light, the processing speed is extremely high, and advanced calculations can also be performed with a relatively simple configuration. Furthermore, advanced processing can be realized with a relatively simple configuration such as changing the angle of incidence of the incident light beam on the E/O modulation element or multiplexing the incident light beam.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a color imaging device.
FIG. 2 is a diagram showing the principle of operation of the E/O element. 3 and 4 are perspective views of the E/O element in the apparatus of the present invention. FIG. 5 is a partial perspective view of the device of the present invention, FIGS. 6 and 8 are luminous flux distribution diagrams, and FIGS. 7 and 9 are plan views of the filter. FIG. 10 is a graph of image signal strength. 10, 15...power supply, 11...light source, 12...
Incident light flux, 13, 13'...E/O element, 14,
14a, 14b, 14c... comb-shaped electrode, 16,
16a, 16b, 16c... Outgoing light flux, 17...
Filter, 18, 18-1 to 12... Light receiving element, 19a, 19b, 20... Adder.

Claims (1)

[Claims] 1. When n and m are integers of 2 or more, the following matrix operation, In an arithmetic device that performs unit strength and the above S ₁ ,
means for emitting n+1 light beams with intensities corresponding to S ₂ , ..., S _o ; and means arranged in a predetermined direction, each emitting the n+1 light beams with an intensity corresponding to S ₁ , S ₂ , ...S _o ; n grating-type electro-optic light modulators that diffract the light beams at different angles in a direction perpendicular to the predetermined direction, and the a ₁₁ , ..., a _oo and b ₁₁ ,
... an optical filter in which portions exhibiting a transmittance corresponding to the absolute value of b _on are arranged in a matrix in a predetermined direction and in a direction perpendicular to the predetermined direction, and transmit the light from the optical modulator; A plurality of photodetectors are arranged in a matrix corresponding to each part, and the output of each photodetector is added or subtracted to correspond to the above-mentioned S ₁ ′, S ₂ ′, ..., S _o ′. and an arithmetic circuit that obtains an electrical signal. 2. The arithmetic device according to claim 1, wherein the n+1 light beams have different wavelengths, and these light beams are superimposed and input to the optical modulator.