JP4934256B2 - Color balance adjusting method and image display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The invention relates to a color balance adjustment method and an image display device, particularly to a color balance adjusting method and the image display device to better control the color balance of the displayed image when displaying the image under the illumination light source arbitrary .
[0002]
[Prior art]
Conventionally, images shot on a photographic film (hereinafter referred to as film) such as a negative film or a reversal film are printed on a photosensitive material (photographic paper) by projecting the film image onto the photosensitive material and exposing the photosensitive material to a surface. The so-called direct exposure (analog exposure) was the mainstream.
In contrast, in recent years, a printing apparatus using digital exposure, that is, an image recorded on a film is photoelectrically read, and the read image is converted into a digital signal. A digital photo printer that prints (finished) images by scanning and exposing the photosensitive material with recording light modulated in accordance with the image data to record the image (latent image) is put into practical use. It was done.
[0003]
In digital photo printers, the exposure conditions during printing can be determined by processing the image data as digital image data, so correction of image skipping and blurring caused by backlighting, flash photography, etc., sharpness (sharpening) ) Processing, color or density feria correction, etc. can be suitably performed to obtain a high-quality print that could not be obtained by conventional direct exposure.
However, the shooting state of a document image on a negative film that has been widely used by general users is not always uniform, and is used under various light sources such as daylight and fluorescent light. When creating a print from the above, if printing is performed with the light quality of the print light source constant, the color of the photographic light source is directly reflected in the print, which may result in an inappropriate print.
[0004]
Therefore, various devices have been conventionally made to adjust the color balance (white balance) on the print. A typical example is the LATD system based on Evans' principle (hypothesis) that “the average of all the colors in the world is gray.” LATD (Large Area Transmission Density) refers to the average transmission density of the entire screen. The LATD method measures the LATD of each frame on a color negative film and prints it according to the RGB density. By changing the light quality of the light source, the average color on the print is made closer to gray. That is, the color balance is obtained by regarding the average color tone of the entire shooting scene as gray.
[0005]
On the other hand, in recent years, digital still cameras (DSC) have begun to spread rapidly. In DSC, a captured DSC image is displayed on a display device and is directly subject to viewing. Therefore, before the DSC image is output as a print, the DSC image itself is not a beautiful image with white balance. must not. As with color negative films, DSC images are taken under various light sources, so if the DSC does not have a function to correct white balance, the image will be unsatisfactory. Therefore, most recent DSCs are equipped with an auto white balance (AWB) function that automatically performs white balance correction.
[0006]
Various techniques have been proposed for automatic white balance adjustment of digital cameras. For example, Japanese Patent Laid-Open No. 2000-78606 discloses a white balance adjustment device that adjusts white balance by changing a limiter region that regulates the gain of an output of an image sensor in accordance with the luminance of a subject. In other words, this is because a limiter that regulates the correction gain is provided because excessive color correction is applied to a scene where the color is biased. Therefore, this limiter area is provided with a light source corresponding to the luminance of the subject. The white balance is adjusted by changing according to the species.
[0007]
[Problems to be solved by the invention]
However, in the conventional white balance adjustment method, since the luminance data is calculated from the photographic scene and the light source is estimated, there is a problem that color failure occurs depending on the scene.
For example, there is a problem that it is difficult to achieve both faithful color reproduction in an indoor scene such as a fluorescent lamp or a tungsten light source and an outdoor scene with many trees.
[0008]
The present invention, wherein has been made in view of the conventional problems, and aims to provide a color balance adjusting method and the image display apparatus capable of optimizing the color balance in response to the type of light source .
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, a first color balance adjustment method according to the present invention is an image having a communication function and a color balance adjustment function under illumination of an illumination device whose illumination light characteristics are controlled by illumination control means. when the display device displays an image on a display screen, a method of image display apparatus adjusts the color balance of the displayed image, the illumination light properties information of the lighting apparatus from the illumination control unit having a communication function to the image display device transmitted, received image display device illumination light properties information of the lighting apparatus that is transmitted from the illumination control unit, in accordance with the received illumination light characteristic information of the lighting apparatus has an image display device adjusts the color balance of the displayed image This is the method.
[0010]
A first image display device according to the present invention is an image display device that displays an image on a display screen under illumination of a lighting device whose illumination light characteristics are controlled by an illumination control unit, and displays the image on the display screen. An image display means, a receiving means for receiving illumination light characteristic information of the lighting equipment transmitted from the lighting control means having a communication function, and an image display according to the illumination light characteristic information of the lighting equipment received by the receiving means. Display control means for adjusting the color balance of the display image by the means.
[0011]
According to a second color balance adjustment method of the present invention, an image display device having a communication function and a color balance adjustment function displays an image on a display screen under illumination of an illumination device whose illumination light characteristics are controlled by an illumination control unit. When displaying, the image display device adjusts the color balance of the display image, and the installation position information indicating that the installation position of the lighting device is indoors from the illumination control means having a communication function to the image display device. The image display device receives the installation position information of the lighting device transmitted from the lighting control means , and the image display device adjusts the color balance of the display image according to the received installation position information of the lighting device. It is the method.
[0012]
A second image display device according to the present invention is an image display device that displays an image on a display screen under illumination of a lighting device whose illumination light characteristics are controlled by an illumination control unit, and displays the image on the display screen. and image display means for, is transmitted from the illumination control unit having a communication function, receiving means for receiving the installation position information indicating that the installation position of the lighting device is indoors, the installation position of the lighting apparatus received by the receiving unit Display control means for adjusting the color balance of the display image by the image display means according to the information.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the color balance adjusting method of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
[0015]
First, a first embodiment of the present invention will be described. In the first embodiment, when the lighting in the entire room is controlled by a home server personal computer, communication is performed between the personal computer and the camera, and the color balance is adjusted on the camera side according to the illumination light characteristics. It is.
FIG. 1 shows the configuration of a camera, illumination control means, etc. that implement the color balance adjustment method of the present embodiment. As shown in FIG. 1, the subject 10 is irradiated by the illumination device 12 and is photographed by the camera 20 under the illumination. The lighting device 12 is controlled by a personal computer (PC) 14 (lighting control means). The camera 20 has a communication function and communicates with the personal computer 14.
[0016]
The illumination device 12 is capable of controlling the amount of light by the personal computer 14, and for example, LED illumination is preferably exemplified. The camera 20 is exemplified by a digital camera, for example, and has a color balance (white balance) adjustment function. The camera 20 communicates with the personal computer 14 by the communication function, and acquires the illumination light characteristic information of the lighting device 12 from the personal computer 14. The camera 20 performs color balance adjustment using the acquired illumination light characteristic information.
[0017]
With the above configuration, in this embodiment, color balance adjustment is performed on the camera side as follows.
That is, when the subject 10 is photographed by the camera 20, information is communicated between the camera 20 and the personal computer 14 (illumination control means) by operating a predetermined switch or the like provided on the camera 20. Thereby, the personal computer 14 transmits the illumination light characteristic information to the camera 20, and the camera 20 acquires the illumination light characteristic information.
[0018]
Upon acquiring the illumination light characteristic information, the camera 20 performs color balance adjustment by the color balance adjustment function according to the illumination light characteristic information. At this time, it is assumed that the illumination light characteristic information includes not only light amount data but also information on the type of light source, that is, spectral distribution data.
Therefore, according to the present embodiment, it is possible to satisfactorily perform color balance adjustment over the entire screen according to the light source, and it is possible to obtain a high-quality image with good color balance.
[0019]
Next, a second embodiment of the present invention will be described.
The second embodiment is also executed by the system configuration shown in FIG. 1 as in the first embodiment. In the second embodiment, the lighting device 12 is controlled by the personal computer 14 in accordance with the shooting mode of the camera 20. The color balance is adjusted.
[0020]
That is, also in the present embodiment, the lighting equipment 12 in the entire room is controlled by the home server personal computer 14. When the subject 10 is photographed by the camera 20 under the illumination of the lighting device 12, communication is performed between the camera 20 and the personal computer 14, and photographing mode information indicating that the camera 20 is in a photographing posture is transmitted to the personal computer 14. To do.
[0021]
Upon receiving the shooting mode information, the personal computer 14 controls the illumination device 12 to control the wavelength distribution of the illumination light so that the illumination light has a color balance suitable for the camera 20. Specifically, for example, when the lighting device 12 is LED lighting, the RGB output ratio is adjusted.
[0022]
At this time, the control of the lighting device 12 by the personal computer 14 may be not only the color balance adjustment but also the light amount adjustment. For example, control may be performed so that the amount of light is increased only during shooting so that shooting can be performed without a strobe.
In addition, the distribution of illumination light that is difficult to produce a shadow at the time of photographing may be obtained by increasing the amount of light from the wall surface.
[0023]
In each of the embodiments described above, the lighting device 12 is controlled by the personal computer 14 (lighting control means), and communication is performed between the camera 20 and the personal computer 14 to transmit information. However, the present invention is not limited to this. For example, the illumination control unit may be integrated with the illumination device, and further, a communication unit may be installed therein, so that the camera and the illumination device communicate directly.
[0024]
Next, a third embodiment of the present invention will be described.
In the third embodiment, the camera only records illumination light characteristic information, and when reproducing an image in a laboratory or the like, the camera performs color balance adjustment using the illumination light characteristic information.
[0025]
FIG. 2 shows a system configuration for executing this embodiment.
As shown in FIG. 2, also in this embodiment, the indoor lighting device 12 that irradiates the subject 10 is controlled by the personal computer 14. The camera 20 is assumed to have a function of recording illumination light characteristic information. For example, when the camera 20 is a film camera, the illumination light characteristic information may be recorded on a film or the like by a magnetic, optical, or other method for each photographing frame. When the camera 20 is a digital camera, each image data may be recorded in an image file (image recording medium) corresponding to the image data.
[0026]
In the laboratory 22, when film or image data obtained by photographing a subject image is received, the film is processed by the digital photo printer 24 and displayed on the display 26, or the image data is output to a recording medium (image file). Or output as a print 28.
The digital photo printer 24 reads illumination light characteristic information from a film or an image recording medium (or directly input data) at the time of print output or image display, and adjusts the color balance for each photographed image based on this. Do.
[0027]
In this embodiment, when the subject 10 is photographed by the camera 20, the camera 20 communicates with the personal computer 14 and acquires the illumination light characteristic information of the lighting device 12 controlled by the personal computer 14. The camera 20 records the acquired illumination light characteristic information on a film or the like.
For example, in the case of a film of a new photographic system (APS), as is well known, an image of a photographic scene on the back surface (non-emulsifier surface) side of the film, that is, the upper part of the image recording area of each frame in which the photographic image is recorded and A magnetic recording layer is formed in the lower area, and cartridge ID, film type, etc., and illumination light characteristic information are recorded together with other photographing information.
In the case of a digital camera, the characteristic information of the illumination light when the image is captured corresponding to each captured image is recorded on the recording medium.
[0028]
After photographing, when a recording film or the like on which an image photographed by a photographing film or a digital camera is recorded is brought into the lab 22, the photographed image is processed by the digital photo printer 24, and the image is reproduced.
At this time, illumination light characteristic information is read from a film or the like, and when image processing is performed, color balance adjustment corresponding to an output target such as the display 26 or the print 28 is performed based on the information.
[0029]
In the first and third embodiments described above, the illumination light characteristic information is transmitted when communicating and transmitting information between the personal computer and the camera. Information may be transmitted to the camera side, and the auto white balance function of the camera or color balance processing in the laboratory may be used.
This is intended to simplify the process by simply identifying whether it is indoors or outdoors, and adjusting the color balance accordingly.
[0030]
As described above, according to each embodiment, by using illumination light characteristic information, color balance adjustment according to the type of light source can be performed, and faithful color reproduction is possible.
[0031]
Next, a fourth embodiment of the present invention will be described.
In each of the embodiments described above, illumination light characteristic information is transmitted between the camera and a personal computer that controls the lighting device. The fourth embodiment described below controls the image display device and the lighting device. The illumination light characteristic information is sent to and from a personal computer to adjust the color balance of the displayed image.
[0032]
FIG. 3 shows the configuration of a system that executes this embodiment.
Also in the present embodiment, the indoor lighting device 12 is controlled by the personal computer 14. It is assumed that the viewer 32 is looking at the image display device 30 (display screen of a television or a personal computer) under the illumination of the lighting device 12.
In the present embodiment, the display screen of the image display device 30 is automatically controlled according to the illumination light characteristics at this time, or conversely, the illumination light is automatically controlled according to the display content (display mode) of the display screen. .
[0033]
For example, when the image display device 30 is a television, the illumination light is controlled according to the display content (display mode). For news programs, normal illumination is used. For movie programs, illumination is applied. It is possible to darken or create a cinema-like atmosphere as a tungsten-like color.
In this case, or even when the display screen is controlled according to the illumination light, the contents of the display screen control according to the illumination light and the illumination light control according to the display contents are set in advance and arbitrarily. Preferably it can be changed.
[0034]
As described above, the color balance adjustment method of the present invention has been described in detail. However, the present invention is not limited to the above embodiment, and various improvements and modifications are made without departing from the gist of the present invention. Of course it is also good.
[0035]
【Effect of the invention】
As described above, according to the present invention, it is possible to perform good color balance adjustment according to illumination light, and it is possible to perform faithful color reproduction that does not depend on the shooting scene.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing an outline of a system that executes a color balance adjustment method according to a first embodiment of the present invention;
FIG. 2 is an explanatory diagram showing an outline of a system that executes a color balance adjustment method according to a third embodiment of the present invention;
FIG. 3 is an explanatory diagram showing an outline of a system that executes a color balance adjustment method according to a fourth embodiment of the present invention;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Subject 12 Lighting equipment 14 Personal computer 20 Camera 22 Lab 24 Digital photo printer 26 Display 28 Print 30 Image display device 32 Viewer

Claims (4)

When an image display device having a communication function and a color balance adjustment function displays an image on a display screen under illumination of a lighting device whose illumination light characteristics are controlled by an illumination control means , the image display device A method for adjusting the color balance,
It transmits illumination light characteristic information of the lighting device from the illumination controller having a communication function to the image display device,
The image display device receives illumination light characteristic information of the illumination device transmitted from the illumination control means ,
Depending on the received illumination light characteristic information of the lighting device, a color balance adjustment method, wherein the image display device is to adjust the color balance of the displayed image. An image display device that displays an image on a display screen under illumination of an illumination device whose illumination light characteristics are controlled by an illumination control means ,
Image display means for displaying an image on the display screen;
Receiving means for receiving illumination light characteristic information of the lighting equipment , transmitted from the illumination control means having a communication function;
An image display apparatus comprising: display control means for adjusting a color balance of a display image by the image display means in accordance with the illumination light characteristic information of the illumination device received by the reception means. When an image display device having a communication function and a color balance adjustment function displays an image on a display screen under illumination of a lighting device whose illumination light characteristics are controlled by an illumination control means , the image display device A method for adjusting the color balance,
Sending installation position information indicating that the installation position of the lighting device is indoor from the illumination control means having a communication function to the image display device ,
The image display device receives the installation position information of the lighting device transmitted from the lighting control means ,
A color balance adjustment method, wherein the image display device adjusts the color balance of a display image according to the received installation position information of the lighting device . An image display device that displays an image on a display screen under illumination of an illumination device whose illumination light characteristics are controlled by an illumination control means ,
Image display means for displaying an image on the display screen;
Receiving means for receiving installation position information indicating that the installation position of the lighting device is indoors, transmitted from the illumination control means having a communication function;
An image display apparatus comprising: display control means for adjusting a color balance of a display image by the image display means in accordance with the installation position information of the lighting device received by the reception means.

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