JP4001501B2 - Imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an imaging apparatus capable of recording still images and moving images, and is applicable to, for example, digital cameras, digital video tape recorders, other general cameras, and video tape recorders.
[0002]
[Prior art]
Here, a configuration example of a general digital camera will be described with reference to FIG. In FIG. 9, light incident on the lens 10 from the subject forms a subject image on the image sensor 14. The image sensor 14 converts the received light into an electrical signal by its photoelectric conversion action. There is a shutter 12 between the lens 10 and the image sensor 14, and a shutter drive circuit 26 controls the shutter 12 to control the amount and timing of light incident on the image sensor 12. The shutter drive circuit 26 is controlled by the system controller 22.
[0003]
The electrical signal photoelectrically converted by the image sensor 14 is input to a sample hold circuit (hereinafter referred to as “S / H circuit”) 16. The S / H circuit 16 samples and holds the electrical signal corresponding to the subject image, and obtains a signal level corresponding to each pixel. The signal sampled and held here is input to an analog / digital conversion circuit (hereinafter referred to as “A / D circuit”) 18 and converted into digital data. The digital data is subjected to processing such as interpolation processing, color processing, edge enhancement and the like by the image data controller 20 and is encoded. DRAM is often used as a temporary storage location for data for this processing operation. The system controller 22 holds data necessary for optimal operation of the system in an EEPROM (electrically erasable programmable ROM) 38, which is read from the EEPROM 38 as necessary and used for computations. The operation switch 46 is operated by an operator of the imaging apparatus, and includes a release switch, a power switch, and a recording / reproducing operation changeover switch.
[0004]
The data processed and encoded by the image data controller 20 is then encoded and compressed by a compression / decompression circuit 34 and stored in an image recording medium 36 such as a magnetic tape.
Since the imaging device 14, the S / H circuit 16, the A / D circuit 18, and the image data controller 20 need to operate in synchronization with each other, a signal for synchronizing them is generated by the timing pulse generation circuit 28, Supplied to each.
In addition, image data being captured and image data that has been captured and saved are sent to the display interface 40, converted into a signal format for display on the display device 42, and displayed on the display device 42. The
[0005]
FIG. 10 shows a part of the image data controller 20 of FIG. The digital image data output from the A / D circuit 18 in FIG. 9 is subjected to white balance correction processing by the white balance correction circuit 50. In white balance, the color temperature and spectral characteristics of the light source that illuminates the subject to be imaged vary, and the color seen by the subject and the color of the recorded image may change depending on the color temperature of the light source. Therefore, it is corrected so that it is close to the color seen by the eyes. The image data after the white balance correction is compressed in gradation by the γ correction circuit 52, compressed to a predetermined format by the compression / expansion circuit 54, and then recorded on the recording medium 36.
[0006]
The recorded image can be viewed by connecting to a PC or TV and playing it, but as mentioned above, the color temperature of the light source that illuminates the subject at the time of imaging varies. The white balance is not always correct. Especially when the image is taken outdoors, there may be a plurality of light sources with different color temperatures, so there may be a sense of incongruity between the impression seen with the eye and the image recorded with white balance correction. .
Even if the white balance correction is performed properly, the impression of the image may vary depending on the viewer, so correction may be performed according to preference using application software on a personal computer.
[0007]
[Problems to be solved by the invention]
However, when white balance correction is performed, it may be ambiguous what color the actual color was when the recorded image was viewed over time. Since the recorded image is after the white balance correction has already been performed by the imaging device, there is also a problem that it is difficult for a viewer to understand how the white balance processing of the imaging device has been performed.
[0008]
The present invention has been made to solve the above-described problems of the prior art. In an imaging apparatus used for imaging in various environments, both the color reference signal and the captured image data are subjected to white balance correction processing. In addition, by superimposing the color reference signal subjected to the white balance correction on a part of the image, it is possible for the operator or the person viewing the captured image to visually recognize how the white balance correction of the imaging apparatus has been performed. An object of the present invention is to provide an imaging apparatus.
[0009]
The reference color sample image is displayed at a predetermined position on the display screen so that the color can be accurately displayed on the screen of the color image display device, and a reference color sample member is disposed in the vicinity of the reference color sample member. A technique is known in which a display color adjustment operation device is provided so that a color sample image and a reference color sample member are compared and these colors match each other. That is the invention described in JP-A-11-19050 and JP-A-11-19051.
However, these conventional examples have a different purpose from the one in which it is possible to visually recognize how the white balance correction is performed as in the present invention, and to achieve the purpose as described below. The means are also different.
[0010]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided an image pickup apparatus capable of forming an image on an image pickup device by an optical system, converting an image picked up by the image pickup device into an electric signal, converting the image into digital data, and recording the color reference. A color reference signal generating means for generating a signal , inputting the image and the color reference signal to a white balance correction circuit inside the image data controller , and performing white balance correction processing on a part of the image subjected to white balance processing; The color reference signal is superimposed and recorded.
[0011]
According to a second aspect of the present invention, in the first aspect of the invention, the color reference signal that has undergone white balance processing and the color reference signal that has not been subjected to white balance correction processing are included in a part of the image that has undergone white balance correction processing. Is superimposed and recorded .
[0012]
According to a third aspect of the present invention, in the first aspect, characterized in that it have a selection switch for selecting whether or not to input the color reference signal to said white balance correction circuit.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of an imaging apparatus according to the present invention will be described with reference to the drawings. In FIG. 1, the same components as those in the conventional example shown in FIG. 9 are denoted by the same reference numerals. In FIG. 1, the lens 10 constitutes an imaging optical system, and a subject image is formed on the imaging surface of the image sensor 14. It has come to image. The image sensor 14 converts received light into an electrical signal by its photoelectric conversion action, and outputs an electrical signal corresponding to the subject image. A shutter 12 is disposed between the lens 10 and the image sensor 14. The shutter 12 is driven by a shutter drive circuit 26, and the shutter drive circuit 26 is controlled by a system controller 22 to control the amount and timing of light incident on the image sensor 14.
[0015]
The electrical signal photoelectrically converted by the image sensor 14 is input to the S / H circuit 16. The signal is sampled and held by the S / H circuit 16 to obtain a signal level corresponding to each pixel of the image sensor 14. The signal sampled and held here is then input to the A / D circuit 18 and converted into digital data. This digital data is subjected to encoding processing, color processing, edge enhancement, and the like in the image data controller 20 and is encoded. A DRAM is usually used as a temporary storage location for data for performing this data processing and encoding processing work. The system controller 22 retains data necessary for operating the system optimally in the EEPROM 38, reads out from the EEPROM 38 as necessary, and is used for calculation and the like. The operation switch 46 is used by an operator to operate the image pickup apparatus. The switch includes a release switch, a power switch, a recording / reproducing operation changeover switch, and the like.
[0016]
The image data that has been subjected to various processes by the image data controller 20 is then encoded and compressed by a compression / decompression circuit 34 and stored in an appropriate image recording medium 36 such as a magnetic tape, disk, or memory. . The image sensor 14, the S / H circuit 16, the A / D circuit 18, and the image data controller 20 need to operate in synchronization with each other, and signals for synchronizing them are generated by the timing pulse generation circuit 28, respectively. To be supplied.
[0017]
In addition, image data being captured and image data that has been captured and saved are sent to the display interface 40, converted into a signal format for display on the display device 42, and displayed on the display device 42. The
The system controller 22 also controls the operation of the lens driving circuit 24. When the operation of the lens driving circuit 24 is controlled by the system controller 22, the lens driving circuit 24 drives the imaging optical system including the lens 10 to perform focusing, zooming, and the like on the subject.
[0018]
FIG. 2 shows a part of the image data controller 20 in the embodiment shown in FIG. In FIG. 2, a color reference signal generation circuit 30 generates an arbitrary color reference signal, and the generated color reference signal is input before the white balance correction process. When the color reference signal is input to the image data controller 20, the color reference signal is subjected to the same correction processing as the captured image by the white balance correction circuit 50. The captured image data is subjected to γ correction processing by the γ correction circuit 52 together with the color reference signal, further compressed by the compression / decompression circuit 54, and recorded on the image recording medium 36.
[0019]
FIG. 2 shows an example of the color reference signal input position. The color reference signal is input to the input side of the white balance correction circuit. Here, a part of the captured image data may be replaced with a color reference signal, or the image data and the color reference signal are separately subjected to white balance correction processing, and the γ correction circuit 52 or the compression / decompression circuit 54 combines the two. May be.
[0020]
Since the image data compressed by the compression / decompression circuit 54 is recorded on the image recording medium 36, when the image data is reproduced on a personal computer or television, a color reference signal 60 is displayed on a part of the image as shown in FIG. You can confirm that it is recorded.
[0021]
FIG. 3 shows another example of the color reference signal input position. In this example, the output of the color reference signal generation circuit 30 is connected to both the input side and the output side of the white balance correction circuit 50, and the color reference signal is input to both the input side and the output side of the white balance correction circuit 50. Like to do. Here, part of the captured image data may be replaced with a color reference signal, or the image data and the color reference signal input to the input side of the white balance correction circuit 50 are separately subjected to white balance correction, You may combine three persons which added the color reference signal input into the output side of the white balance correction circuit 50 later. FIG. 8 shows an example of an image recorded by combining color reference signals. The lower left is a color reference signal 62 synthesized before white balance correction, and the lower right is a color reference signal 60 synthesized after white balance correction. Show. By comparing the two color reference signals 60 and 62, it can be seen at a glance how the color is corrected by the white balance correction circuit 50 of the imaging apparatus.
[0022]
Whether or not the color reference signal is input may be arbitrarily selected by the operator of the imaging apparatus. The selection switch 44 shown in FIG. 1 is a switch for that purpose. When selecting the input of the color reference signal with the selection switch 44, the color reference signal may be input before the white balance correction processing, as in the example shown in FIG. 2, or as shown in FIG. As in the example, the color reference signal may be input before the white balance correction process and after the white balance correction process.
FIG. 6 schematically shows an image when the color reference signal is not superimposed. 7 and 8 schematically show examples of images when the color reference signal is superimposed as described above.
[0023]
FIG. 4 is a flowchart illustrating an operation example of the embodiment of the imaging apparatus described above. First, when it is confirmed that the release switch is turned on (S1), preprocessing is performed (S2), the lens is driven to perform focus adjustment (S3), and an exposure operation is performed (S4). Captures a subject image and converts it into an electrical signal. Next, the state of the selection switch 44 for selecting whether or not to input a color reference signal, that is, whether it is on or off is confirmed (S5). If the selection switch 44 selects the input of the color reference signal, a color reference signal is generated (S6) and input to the white balance correction circuit, and the captured image data is read (S7). And the color reference signal are combined (S8), and white balance correction is performed on the combined signal (S10). That is, in this case, white balance correction is performed together with the image data and the color reference signal. If the selection switch 44 selects the one that does not input the color reference signal, the color reference signal is not generated, the captured image is read (S9), and white balance correction is performed only on this image data ( S10). After that, γ correction is performed (S11), compression is performed by a compression / decompression circuit (S12), recording is performed on an appropriate recording medium, and a series of imaging scans is completed.
[0024]
FIGS. 5A, 5B, and 5C show various examples of color reference signals generated by the color reference signal generation circuit. As can be seen from this example, a general color array or a gray scale array can be considered. These may be selected by the operator according to the application and preference.
[0025]
【The invention's effect】
According to the first aspect of the present invention, the color reference signal generation means for generating the color reference signal is provided, and the image and the color reference signal are input to the white balance correction circuit inside the image data controller , and the white balance processing is performed. by superimposing the color reference signal a white balance correction processing on a part of the image recording, the color reference signal included in the recorded image, or the operator white balance processing is how made to know be able to.
[0026]
According to the invention of claim 2 Symbol placement, in the invention according to the first aspect, a part of the white balance correction processed the image, the white balance processing by said color reference signal and a white balance correction process prior to the color By superimposing and recording the reference signal, the operator can know how the white balance processing was performed, and contrast the colors when the white balance processing is performed and when it is not performed. Can be observed.
[0027]
According to the invention described in claim 3 , it is possible to select whether or not to record the color reference signal in the recorded image.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of an imaging apparatus according to the present invention.
FIG. 2 is a block diagram illustrating a specific configuration example of an image data controller in the embodiment.
FIG. 3 is a block diagram illustrating another specific configuration example of the image data controller.
FIG. 4 is a flowchart showing the operation of the embodiment.
FIG. 5 is a chart showing various examples of color reference signals that can be used in the present invention.
FIG. 6 is a schematic diagram illustrating an example of an image when a color reference signal is not superimposed.
FIG. 7 is a schematic diagram illustrating an example of an image on which a color reference signal is superimposed.
FIG. 8 is a schematic diagram illustrating another example of an image on which a color reference signal is superimposed.
FIG. 9 is a block diagram illustrating an example of a conventional imaging device.
FIG. 10 is a block diagram showing a specific configuration example of an image data controller in the conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Lens which comprises optical system Image pick-up element 30 Color reference signal production | generation means 44 Selection switch 50 White balance correction circuit

Claims (3)

In an imaging apparatus capable of forming an image on an imaging element by an optical system, converting an image captured by the imaging element into an electric signal, converting the image into digital data,
A color reference signal generating means for generating a color reference signal;
The image and the color reference signal are input to a white balance correction circuit inside the image data controller, and the color reference signal subjected to white balance correction processing is superimposed and recorded on a part of the image subjected to white balance processing. An imaging device. 2. The imaging apparatus according to claim 1 , wherein the color reference signal subjected to white balance processing and the color reference signal before white balance correction processing are superimposed and recorded on a part of the image subjected to white balance correction processing. An imaging device that is characterized. An image pickup apparatus according to claim 1, an imaging apparatus, characterized by chromatic selection switch for selecting whether or not to input the color reference signal to said white balance correction circuit.

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