JP2001061071A - Image correction device and image correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an image correction device that can surely extract a red-eye or gold-eye area with a simple algorithm. SOLUTION: The image correction device is provided with a display means that displays an image of an object photographed by emitting a strobe light onto the object, an image data selection means 46 that designates a prescribed area including eyes in the image displayed on the display means through a manual operation, an arithmetic means 50 that extracts a red-eye or gold-eye from a prescribed area designated by the manual operation and a red-eye correction means 51 that corrects the extracted red-eye or gold-eye.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image correcting apparatus and an image correcting method, and more particularly to an apparatus and a method for detecting a red eye generated when a subject such as a person is photographed by a strobe light and restoring the red eye.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 64532/1994 discloses that a subject having a low luminance and a photographing condition in which red-eye occurs when photographing using an electronic flash device are determined, and red-eye information indicating this is printed on the film margin. The printer discloses a method of performing a heating correction process after printing a frame in which red-eye information is detected.

[0003] Japanese Patent Application Laid-Open No. 2-114253 discloses a method of adjusting the amount of printing light applied to a red-eye portion of a photographic original during printing exposure.

Further, Japanese Patent Application Laid-Open No. 2-144528 discloses a red-eye occurrence warning signal when the distance signal between the optical axis of the photographing lens and the center of the strobe discharge tube and the subject distance have a predetermined relationship. A method is disclosed.

[0005]

However, in the above-mentioned Japanese Patent Application Laid-Open No. 2-64532, the correction processing is not described in detail. Requires fairly sophisticated techniques.

In Japanese Patent Laid-Open No. 2-114253, the red-eye portion is a very small area with respect to the entire area of the photograph, and color correction is performed only on this portion (red-eye portion) by a conventional method. Was very difficult.

Further, the above-mentioned Japanese Patent Application Laid-Open No. 2-144528
As described above, when the strobe and the camera are integrated and made compact as in a camera with a built-in strobe, there is a disadvantage that the probability of occurrence of red-eye is inevitably increased.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an image correcting apparatus and an image correcting method capable of reliably extracting a red-eye or gold-eye area with a simple algorithm. It is to provide a correction method.

[0009]

According to a first aspect of the present invention, there is provided an image correcting apparatus, comprising: display means for irradiating a strobe light to display a photographed image; Means for manually specifying a predetermined area including an eye in the displayed image; means for extracting red eye or gold eye from the predetermined area specified by the manual operation; means for correcting the extracted red eye or gold eye And

According to a second aspect of the present invention, in the image correction apparatus according to the first aspect, a predetermined area including a red eye or a gold eye is manually surrounded by a contour line.

According to a third aspect, in the image correction apparatus according to the first aspect, the image data extracted from the predetermined area is converted into data representing chromaticity, and based on the converted chromaticity data. Extract red or gold eyes.

According to a fourth aspect, in the image correction apparatus according to the third aspect, an area of the chromaticity data in which a red component is equal to or more than a predetermined value is determined as a red eye.

According to a fifth aspect of the present invention, in the image correction apparatus according to the third aspect, an area in which the red component and the green component of the chromaticity data are equal to or larger than a predetermined value is determined to be gold.

According to a sixth aspect, in the image correction apparatus according to the first aspect, red eyes are extracted based on a ratio of three color components.

According to a seventh aspect, in the image correction apparatus according to the first aspect, red eyes are extracted based on a ratio of three color components and a value of a red component.

An eighth aspect of the present invention is an image correction method, comprising the steps of displaying an image irradiated with strobe light on a display means, and displaying a predetermined area including an eye in the image displayed on the display means. The method includes a step of specifying by manual operation, a step of extracting a red eye or a gold eye from a predetermined region specified by the manual operation, and a step of correcting the extracted red or gold eye.

[0017]

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

FIG. 1 is a diagram showing the configuration of a red-eye correction system to which the red-eye correction device of the present embodiment is applied. In FIG. 1, a white light from a light source 1 is diffused by a diffusion plate 2
It is guided to the color line sensor 6 through the film 4 and the lens 5 inside. An image of the film is formed on a color line sensor 6 by a lens 5. The output signal of the color line sensor 6 is converted into a digital value by an A / D converter 8 via an amplifier circuit 7.

The digitally converted signal is sent to a memory 11 by a workstation 10 through an I / O port 9.
Is stored as image data. The sensor scanning device 12 scans the color line sensor 6 in a direction orthogonal to the sensor 6 to obtain one frame of image data. Video RAM 13
Stores monitor display data obtained by converting the image data into a predetermined density and color. The display data is displayed on a monitor 14 as a display unit.

The magnetic head 15 is a magnetic head for reading data recorded on a magnetic recording portion of a film as described later. The magnetic data read by the magnetic head 15 is amplified and waveform-shaped by the signal processing circuit 16,
It is stored in a memory in the workstation 10 via the I / O port 9. A film feed roller 17 feeds the film 4. Reference numeral 18 denotes a notch detection sensor. Thus, the scanner 19 is configured.

The LSI card 20 stores correction data, the number of notches, data on the intervals between the notches, and the like. The workstation 10 performs various calculations and controls, such as print color balance control and temperature control, which will be described later, based on various information obtained from the scanner 19. Further, the printer 21 is a device for copying an optimum print based on information calculated by the workstation 10.

FIG. 2 is an overall control block diagram of the camera. In the figure, reference numeral 22 denotes a CPU for controlling and calculating the entire camera. 23 is a photometric sensor for exposure control, 24 is an amplifier circuit for amplifying the analog output signal of the photometric sensor 23, and 25 is an AD converter for converting the analog output signal of the amplifier circuit 24 to a digital signal.

The photometric data converted to digital values is CP
The film sensitivity SV and the photographic lens aperture value A stored in the memory in the U22 and input by the photographic information input circuit 26
An apex calculation is performed between V and the exposure correction value CV to obtain a shutter speed TV. 27 is an optical system for distance measurement. The principle of distance measurement is obtained from the distance between two images obtained by dividing the pupil of a known photographing lens, and the distance measurement optical system 27 is constituted by a field lens separator lens and the like.

Reference numeral 28 denotes a CCD, and 29 denotes a CCD drive circuit. The CCD output signal sequentially transmitted according to the timing signal of the drive circuit 29 is amplified by the amplifier circuit 30 and then converted to a digital value by the AD converter 31. The CCD output signal converted to the digital value is output to the CPU 2
2 is stored in the memory. In the CPU 22, the above CCD
A defocus amount of the photographing lens is calculated based on the output signal.

The CPU 22 also calculates the distance 1 to the subject. The CPU 22 drives the lens driving circuit 32 based on the defocus amount, and sets the taking lens to a focal position. The above focus detection operation is performed after the CPU 22 detects that the AF start switch 32 is closed. 33 is a flash device. A signal S1 is connected from the CPU 22 to the strobe device 33. S1
Is a signal for causing the strobe device 33 to start strobe light emission. Whether or not to fire a strobe is controlled according to the result of the apex calculation.

Reference numeral 34 denotes a liquid crystal display section for displaying photographing information such as a shutter speed and a camera mode. Reference numeral 35 denotes a liquid crystal drive circuit that drives the liquid crystal display unit 34. When the strobe light is emitted and the distance to the subject is shorter than a predetermined value, it is determined that the possibility of occurrence of red eyes is high.
Is recorded in the magnetic recording section 37 of the predetermined section. The signal processing circuit 58 and the magnetic head 39 are devices for writing magnetic information.

FIG. 3 shows a film 36 having a magnetic recording section 37.
FIG. Reference numeral 40 denotes a release switch. When the release switch 40 is closed, the energization of the magnet 41 for stopping the shutter front curtain system is interrupted, and the shutter front curtain starts running. When the film exposure is performed for a predetermined time, the power to the shutter rear curtain system stopping magnet 42 is cut off, the rear curtain of the shutter runs, and the exposure ends.

Next, the operation of the red-eye correction system of FIG. 1 will be described with reference to the flowcharts of FIGS.

In FIG. 8, first, shading correction is performed (S1). Here, the sensitivity variation of the sensor,
The distortion due to the uneven light amount of the light source is corrected. Then
Based on the image data detected by the color line sensor 6, the entire screen average transmission density (LATD) of the film is measured (S2). And LATD and LSI card 20
The density and color correction of the video data R, G, and B for displaying the film image on the monitor 14 are performed based on the correction data from (S3 to S5). Next, the corrected video data is stored in the video RAM 13 (S6).

Next, the film magnetic data is read (S
7) As a result, when the frame currently being processed is likely to have red-eye, an instruction is given on the monitor 14 in FIG. 1 to set a red-eye area at the lower left of the screen as shown in FIG. You. When the operator traces a relatively narrow area including the red eye with the light pen, this area is displayed as an outline of the correction section area as shown by a dotted line in FIG.

FIG. 5 is a diagram showing a basic configuration for arranging the transparent touch panel switch 38 on the screen of the monitor 14 and detecting the area designated by the operator at the workstation. FIGS. 6 and 7 are diagrams for explaining the configuration of the transparent touch panel in detail. The transparent touch panel switch 38 and the monitor 14 are configured as shown in FIG. Reference numeral 39 denotes a graphic sheet serving as an operation surface of the transparent touch panel switch 38. Graphic sheet 3
9, a transparent upper electrode 40 and a lower electrode 41 are arranged via a spacer 42, and an electrode X integrated with the upper electrode 40 and an electrode Y integrated with the lower electrode 41 are provided at a position where the spacer 42 does not exist. Normally, one switch (38a) of the transparent panel switch 38 which is provided so as not to be in contact with the transparent panel switch 38
Is configured.

Graphic sheet corresponding to electrodes X and Y
39 is pressed by a finger or a pen on the electrode X.
And Y come into contact and the switch is turned on. Transparent panels
The lower electrode 41 of the switch 38 is
It is adhered on the display screen of the monitor 14. FIG. 6 (a)
As shown in FIG.
X₁, X_Two, X_Three… Connected to multiple switches
They are arranged in a matrix that crosses each other. Now
Transparent panel switches 38 arranged in a matrix
At line X₁, X_Two, X_ThreeVia IO port 9
6 (b) sequentially from the workstation 10.
When such repetitive pulses are sent, the transparent panel
Depending on which switch on switch 38 is on
Line Y ₁, Y_Two, Y_Three... the above line X on the throat line
₁, X_Two, X_ThreeWhich line pulse is output
Is determined. The device for indicating the red-eye area is as described above.
Known light pen input method other than the transparent panel switch and
It may be indicated by a mouse.

Returning to FIG. 8, when the setting of the red-eye area (S9) is completed, the workstation 10 next inputs an image of the area where the red-eye exists (S10). Next, red-eye correction is performed from the designated area (S11).
The red-eye correction will be described later in detail.

If there is no possibility of occurrence of red-eye in S8, the print density and the R, G, B color correction are performed (S12, S13). Next, after a reflectance-voltage linear signal (BGR) is converted into a density-voltage linear signal (YMC) by a gamma correction unit (not shown), gray components in the three-color signal are separated (under color removal: UCR and UCR). ), And a black signal is generated (S14, S15).

Then, color correction masking is performed using a predetermined masking equation (S16). Next, after gradation correction is performed, sharpness correction such as edge enhancement smoothing is performed (S17, S18). Next, printing is executed based on the image data on which the above processing has been performed (S19). Next, the film 4 is fed by one frame, and the same processing is executed again (S20).

Next, the red eye correction program shown in FIGS. 9 to 12 will be described.

In FIG. 9, first, chromaticity conversion processing is performed on three color component outputs RGB of a color image of a predetermined area including red eyes (S30). The chromaticity conversion is a conversion process in which the brightness of a color pixel is kept constant and only a hue component is left. Assuming that the chromaticity conversion output of the three color components is rgb,

[0038]

(Equation 1)

## EQU2 ## When the chromaticity conversion is completed, the average value r ^* of the red component is calculated (S31). Next, with respect to the chromaticity conversion value r of the red component of all pixels in the predetermined area, an image area satisfying r> r ^* + C0 (C0 is a constant) (2) is extracted (S32). Assuming that C0 is substantially equal to 30, it has been found that only the red-eye region can be extracted by equation (2). Table 1 shows the average values r ^* , g ^* , b ^* of the three color components of each pixel after the chromaticity conversion in the area A including the red eye as shown in FIG. It is a result of actually measuring the average values r ^* , g ^* , and b ^* of the three color components of each pixel after the chromaticity conversion.

[0040]

[Table 1]

It should be noted that instead of equation (2), r> r ^* × K0 (K0 is a constant) (3)

As can be seen from Table 1, the red-eye region is characterized in that the red chromaticity conversion output value r ^* is much larger than the average value r ^* of the chromaticity conversion outputs of a relatively wide region including the red eye. You can see that there is.

Returning to FIG. 9, a color conversion process is performed on the extracted image area (S33). As a method of determining the color of the conversion, the color is expressed by the color r ^* : g ^* of the area A in FIG.
It has been found that when the brightness is slightly darkened in accordance with b ^* , there is no strange feeling. Alternatively, a method of presenting a color sample on a monitor and selecting an appropriate color from the sample may be used.

In rare cases, the red eye may include a shining portion of gold (hereinafter referred to as “gold eye”).
This part cannot be extracted by the algorithm of FIG. Table 2 shows the average value R of the three color component outputs of the image output of the gold portion.
The average output R ^* , G ^* , B ^* of the three color components in the area corresponding to A in FIG. 4 including ^* , G ^* , B ^* and the gold eyes is obtained.

[0045]

[Table 2]

FIG. 10 shows an algorithm for extracting the gold. In FIG. 10, first, outputs R ^* , G ^* , and B ^* of three color components in a portion corresponding to the area A in FIG. 4 are obtained (S4).
0). Next, an image area where the red component R and the green component G of each pixel are R> R ^* + C1, G> G ^* + C2 (C1 and C2 are constants) (4) is extracted (S41). Next, a color conversion process is performed using the extracted image region as a gold region (S4).
2). That is, as can be seen from Table 2, the gold area is extracted and color-corrected by utilizing the fact that G ^* and R ^* are larger than the area A in the gold area as compared to the other areas.

It should be noted that instead of equation (4), R> R ^* × K1, G> G ^* × K2 (K1 and K2 are constants) (5)

FIG. 11 shows the ratio G / R and B of the three color components of each pixel.
/ R, that is, another embodiment in which red eyes are extracted based on the tint of each pixel. In FIG. 11, first, 3
An image area where the ratio of the color components RGB is C3 <G / R <C4 and C5 <B / R <C6 (where C3 to C6 are constants) (6) is extracted (S50). Next, color correction is performed on the extracted area (S51).

In the method shown in FIG. 11, the skin tone and the red-eye color may sometimes be the same, and in this case, unless the area A shown in FIG.

FIG. 12 is an improvement of this, and focuses on the fact that the red-eye region is brighter than other regions, and adds a condition of brightness to the tint component.

In FIG. 12, first, the average values R ^* , G ^* , and B ^* of the three color components RGB of each pixel are calculated (S6).
0). Next, an image area of C3 <G / R <C4 and C5 <B / R <C6 and R> R ^* + C7 (C3 to C7 are constants) (7) is extracted (S61). Next, a color conversion process is performed on the extracted red-eye region (S62). (7)
In the formula, G> G ^* + C8 instead of R> R ^* + C7
(C8 is a constant).

Although FIGS. 9 to 12 have been described as independent algorithms, some of them may be used in combination. For example, if the conditions of the image area extraction in FIGS. 9 and 10 are combined in OR, it is possible to repair eyes in which red eyes and gold eyes are mixed.

In the above, all the arithmetic processing is performed in the workstation 10. FIG. 13 is a block diagram illustrating the configuration of another embodiment of the present invention.
In FIG. 13, reference numeral 44 denotes a scanner for converting a film image into digital image data of three color components. Reference numeral 45 denotes an image memory for storing the converted digital image data. Reference numeral 46 denotes image data selecting means for extracting only image data of a designated area from the image memory 45. 47 is a means for calculating the average values R ^* , G ^* , B ^* of the respective three-color image data RGB selected by the image data selecting means 46; 48 is each of the three colors selected by the image data selecting means 46; This is means for obtaining chromaticity conversion values r, g, b from the image data R, G, B. 49 is an average value of the above r, g, b, r ^* , g ^* ,
This is a means for obtaining b ^* . Numeral 50 denotes means for calculating an algorithm and extracting a red-eye area as shown in FIGS. Reference numeral 51 denotes red-eye correction means for correcting the color of the red-eye area. Reference numeral 52 denotes an image processing means for performing various image processing as described above in order to print the red-eye-corrected image data, and reference numeral 53 denotes a printer.

Next, the operation of FIG. 13 will be briefly described.

The digital image data converted by the scanner 44 is stored in the image memory 45. From the image data stored in the image memory 45, only data in a predetermined area designated by the image data selecting means (designating means) 46 is selected, and the average value R ^* , G ^* of the three color components is selected by the average image data calculating means 47 ^. , B ^* are calculated. Further, the chromaticity data r, g, b are calculated by the chromaticity conversion means 48. Further, the chromaticity average value calculating means 49 calculates the average values r ^* , g ^* , b ^{* of the} chromaticity data. The arithmetic means 50 executes the various arithmetic operations shown in FIGS. 9 to 12 based on the above data to extract the red-eye region. When the red-eye area is extracted, the red-eye correction means 51 corrects the color of the red-eye data in the image memory 45.

The image data whose red-eye has been corrected is subjected to various kinds of image processing by the image processing means 52 and then printed by the printer 53.

[0057]

As described above, in the present invention,
An image photographed by irradiating a strobe light is displayed on a display means, and a predetermined area including an eye in the image displayed on the display means is designated by a manual operation. Since the gold eyes are extracted, it is possible to easily and reliably detect the red-eye or gold-eye area. In addition, since the face image is color-separated into three color components and the red-eye or gold-eye region is extracted based on the hue or chromaticity or the ratio of the three-color components, the red-eye or gold-eye region can be reliably detected with a simple algorithm. It becomes possible to extract.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a red-eye correction system to which a red-eye correction device according to an embodiment is applied.

FIG. 2 is an overall control block diagram of the camera.

FIG. 3 is a plan view of a film having a magnetic recording unit.

FIG. 4 is a diagram for explaining how to set a red-eye area.

FIG. 5 is a diagram showing a basic configuration for detecting, by a workstation, an area designated by an operator.

FIG. 6 is a diagram for describing a configuration of a transparent touch panel in detail.

FIG. 7 is a diagram showing a structure of a transparent touch panel.

FIG. 8 is a flowchart illustrating the operation of the red-eye correction system of FIG. 1;

FIG. 9 is a diagram for explaining an algorithm for red eye correction.

FIG. 10 is a diagram for explaining an algorithm for extracting gold eyes.

FIG. 11 is a diagram illustrating another embodiment of a red-eye correction algorithm.

FIG. 12 is a diagram showing an example in which the embodiment of FIG. 11 is improved.

FIG. 13 is a block diagram showing a configuration of another embodiment of the present invention.

[Explanation of symbols]

 44 Scanner 45 Image Memory 46 Image Data Selection Means 47 Average Image Data Calculation Means 48 Chromaticity Conversion Means 49 Chromaticity Average Value Calculation Means 50 Calculation Means 51 Red Eye Correction Means 52 Image Processing Means 53 Printer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // G03B 27/80 H04N 1/40 D

Claims (8)

[Claims] 1. A display means for displaying an image photographed by irradiating strobe light, a means for manually designating a predetermined area including an eye in an image displayed on the display means, and a designation by the manual operation An image correcting apparatus, comprising: a unit for extracting a red eye or a gold eye from a predetermined area that has been extracted; and a unit for correcting the extracted red or gold eye. 2. The image correction apparatus according to claim 1, wherein a predetermined area including a red eye or a gold eye is manually surrounded by a contour line. 3. The image according to claim 1, wherein the image data extracted from the predetermined area is converted into data representing chromaticity, and red-eye or gold-eye is extracted based on the converted chromaticity data. Correction device. 4. The image correcting apparatus according to claim 3, wherein an area of the chromaticity data in which a red component is equal to or more than a predetermined value is determined as red-eye. 5. The image correcting apparatus according to claim 3, wherein an area where a red component and a green component of the chromaticity data are equal to or larger than a predetermined value is determined to be gold. 6. The image correction apparatus according to claim 1, wherein red eyes are extracted based on a ratio of three color components. 7. The image correcting apparatus according to claim 1, wherein red eyes are extracted based on a ratio of three color components and a value of a red component. 8. A step of displaying an image irradiated with strobe light on a display means, a step of manually designating a predetermined area including an eye in the image displayed on the display means, and a step of designating by the manual operation. Extracting a red-eye or gold-eye from the predetermined area, and correcting the extracted red-eye or gold-eye.