JPH11284940A - Still image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively and easily provide a print image of good image quality in a short time by controlling the characteristic of a signal processing circuit based on the analysis result of a comparison/analysis means. SOLUTION: A reference signal read from a reference signal memory 6 is supplied to one fixed contact point of a switch 7, whereas image data read from a memory 4 is supplied to the other fixed contact point of the switch 7. The reference signal is also inputted to a comparison analysis/characteristic control mechanism 8 and the image data is also inputted to the comparison analysis/characteristic control mechanism 8. The mechanism 8 compares read-out image data with the reference signal. Deformation (deformation of a hue, deformation of the saturation degree of a color, change of a γ value, change of white balance) of image data against luminance information and chrominance information, which are contained in the reference signal, is analyzed and the signal processing characteristic of a signal processing circuit 3 is controlled based on the analyzed result.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for photographing a still image electronically, such as an electronic still camera or a digital still camera, and more particularly, to an inexpensive setting operation for obtaining a printed image of good quality. The present invention relates to an apparatus that can be performed easily and in a short time.

[0002]

2. Description of the Related Art As a device for electronically photographing a still image,
An electronic still camera using a floppy disk or the like as a recording medium and a digital still camera using a digital recording medium such as a memory card exist. In addition, some video cameras (camera-integrated video tape recorders) that support still images that have a function of playing back one field or one frame of images of a captured moving image as a still image exist. . A scanner that scans a drawing and converts the reflected light into an electric signal to input graphic data to a computer or the like can also be said to be a device that captures a still image of the graphic on the drawing.

In the present specification, a device having a function of electronically capturing a still image, such as an electronic still camera, a digital still camera, a video camera or a scanner compatible with a still image, is referred to as a “still image capturing device”. ".

FIG. 5 is a block diagram showing a basic configuration of a digital still camera which is a kind of such a still image photographing apparatus. In the digital still camera 10, image light of a subject passing through the lens 1 is photoelectrically converted by the CCD image sensor 2. The output signal of the CCD image sensor 2 is subjected to predetermined video signal processing (level adjustment processing, signal processing) by a signal processing circuit 3 comprising an analog circuit or a digital circuit such as a DSP.
Image data (luminance signal and color signal) is generated by performing luminance signal processing, color signal processing, gamma correction processing, image compression processing, and the like. This image data is stored in the memory 4
(Equivalent to a memory card or the like).

[0005] The image data read from the memory 4 is
Output to the outside via the interface 5. There are various destinations for sending image data, such as a monitor and a personal computer. Digital still cameras are often used to print out captured images, and a printer 20 for that purpose is also one of the destinations. .

The basic structure of an electronic still camera or a video camera for still images is the same as that shown in FIG. 5 except that a floppy disk, a video tape, and the like correspond to the memory 4, respectively. Also, the basic configuration of the scanner,
It is the same as that shown in FIG. 5 except that it has a light source for illuminating the drawing and does not have a storage medium corresponding to the memory 4.

By the way, the basic characteristics (eg, color reproduction characteristics, luminance reproduction characteristics, color balance characteristics, γ characteristics (change rate of photosensitive density), etc.) of a printer used for printing out such a still image are various. However, if the combination of the digital still camera and the printer is not good, a print image with good image quality as expected by the user may not be obtained. In such a case, the following method (a) or (b) has conventionally been adopted as a method for improving image quality.

(A) Captured image data is loaded into a personal computer, and color tone processing and the like are performed using retouch software (application software for image processing). (B) The printout is repeated by trial and error while gradually changing the settings of the printer (and, if possible, the settings of the camera).

[0009]

However, the above method (a) requires an expensive personal computer and retouching software, and has a disadvantage that the operation requires a certain amount of learning. In addition, the method (b) has the disadvantages that it takes time and effort to obtain a print image of good image quality and often wastes a number of print sheets.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a still image photographing apparatus capable of performing an inexpensive, simple, and short time setting operation for obtaining a print image of good image quality. Things.

[0011]

According to the present invention, there is provided a still image photographing apparatus having a signal processing circuit for performing video signal processing on an output signal of an image pickup device as shown in FIG. Reference signal storage means for storing an output reference signal, reference signal output means for outputting the reference signal read from the reference signal storage means as a signal to be printed out, image data and a reference signal generated by a signal processing circuit. Comparison analysis means for comparing the reference signal read from the storage means and analyzing the deformation of the image data with respect to the reference signal, and characteristic control means for controlling the characteristics of the signal processing circuit based on the analysis result of the comparison analysis means. It is characterized by having.

According to this still image photographing apparatus, a printout reference signal including predetermined image information is stored, and this reference signal is output as a signal to be printed out.

The setting operation to be performed by the user in order to obtain a print image of good image quality from an image captured by the still image capturing device is as follows. First, the reference signal output as the signal to be printed out is sent to the printer which the user intends to use, and the printout is performed. Subsequently, a printed image of the printed reference signal is shot by the still image shooting device.

Then, the output signal of the image pickup device having the printed image of the reference signal as a subject is processed by a signal processing circuit to generate image data. Then, the deformation of the image data with respect to the original reference signal is analyzed by the comparison analysis means. This deformation is caused by characteristics of the printer and the like. In other words, due to the characteristics of the printer and the like, the image quality of the print image is degraded by the analyzed deformation.

The characteristic control means controls the characteristic of the signal processing circuit.
Control is performed based on the analysis result of this comparison analysis means. When the still image captured by the still image capturing device is subsequently printed out by the same printer, the characteristics of the printer are corrected by the processing in the signal processing circuit, so that the image quality of the printed image is good. become.

As described above, according to the still image photographing apparatus, the printout of the reference signal is performed once, and a print image of the reference signal is photographed. Therefore, it is not necessary to prepare an expensive personal computer or retouching software and to learn the operation as in the related art, or to waste time, labor and print paper while changing printer settings. A print image with good image quality can be obtained in a short time. In particular, in the case where the same printer is not always used but the printer to be used is replaced or a plurality of printers are selectively used, there is a great advantage that the setting operation is simple and can be performed in a short time. It can be said that.

As an example, the characteristic control means controls the characteristics of the signal processing circuit so that the output signal of the image sensor is deformed in the reverse of the deformation of the image data analyzed by the comparison and analysis means. Is preferred. By doing so, the deformation of the image data due to the characteristics of the printer and the like is canceled out by the deformation in the signal processing circuit, so that a print image with better image quality can be obtained.

[0018]

FIG. 1 is a block diagram showing the structure of a digital still camera to which the present invention is applied. In FIG. 1, the same parts as those in FIG. .

The digital still camera 11 is provided with a reference signal memory 6. In the reference signal memory 6, when printed out, for example, as shown in FIG. 2, one of a total of nine colors of magenta M, cyan C, yellow Y, gray, white, black, red R, green G, and blue B is stored. A reference signal including luminance information and color information for obtaining a printed image in which a portion for each color is arranged in a grid pattern is stored.

The reference signal read from the reference signal memory 6 is supplied to a switch 7 provided at a stage before the interface 5.
Is supplied to one of the fixed contacts (7a in the figure). On the other hand, the image data read from the memory 4
Is supplied to the other fixed contact (7b in the figure). The switch 7 is controlled to be switched based on the operation of a predetermined operation button (not shown) provided on the operation panel of the digital still camera 11, thereby selecting a reference signal and image data. It can be externally output.

The digital still camera 11 is provided with a comparative analysis / characteristic control mechanism 8. The reference signal read from the reference signal memory 6 is also input to the comparison analysis / characteristic control mechanism 8. On the other hand, the image data read from the memory 4 is also input to the comparison analysis / characteristic control mechanism 8.

The comparison analysis / characteristic control mechanism 8 compares the image data read from the memory 4 with the reference signal read from the reference signal memory 6 to determine the luminance information and the color information (color information) contained in the reference signal. The image data is analyzed for deformation (hue deformation, color saturation deformation, γ value change, white balance change, etc.) with respect to FIG. 2), and based on this analysis result, the signal processing circuit 3 It controls the signal processing characteristics. The comparative analysis / characteristic control mechanism 8 is configured by, for example, storing a program for executing such processing in a microcomputer that controls each unit of the digital still camera 11.

Next, an example of a setting operation to be performed by a user in order to obtain a print image of good quality from an image captured by the digital still camera 11 and an operation of the digital still camera 11 corresponding thereto will be described.

First, the user operates the operation buttons to output a reference signal from the digital still camera 11 and prints out the image using the printer 20. At this time, the reference signal is deformed according to the color reproduction characteristics, the luminance reproduction characteristics, the color balance characteristics, the γ characteristics, and the like of the printer 20. FIG. 3A conceptually shows how the reference signal is deformed and the like. The reference signal is A, the deformation received by the printer 20 is B ¹ , and the printed image is A * B.
Each is represented as ¹ .

Subsequently, the user sets the printout of the reference signal printed out in a shooting environment in which the color temperature and brightness of the illuminating light are the same as when the original subject is shot after this setting operation. So, digital still camera 1
Shoot with 1. At this time, the print image is deformed according to the color temperature and brightness of the illumination light. In FIG. 3, this deformation is represented by C ¹ , and the deformed print image is represented by A * B ¹ * C ¹ .

In the digital still camera 11, the CCD image pickup device 2 having the printed image subjected to this deformation as a subject
Are processed by the signal processing circuit 3 to generate image data, and this image data is stored in the memory 4. Then, the image data read from the memory 4 and the reference signal read from the reference signal memory 6 are input to the comparison analysis / characteristic control mechanism 8, and the deformation of the image data with respect to the reference signal is compared with the comparison analysis / characteristic. Control mechanism 8
Is analyzed by In the example of FIG. 3, the deformation analysis B ¹ * C ¹ is analyzed by the comparative analysis / characteristic control mechanism 8.

Based on the result of the analysis, the comparative analysis / characteristic control mechanism 8 instructs the signal processing circuit 3 to apply a reverse deformation to the image data to the output signal of the CCD 2. Instructs adjustment of signal processing characteristics. The signal processing circuit 3 adjusts the signal processing characteristics according to the instruction from the comparison analysis / characteristic control mechanism 8. In the example of FIG.
FIG. 4B shows the reverse deformation by the signal processing circuit 3 as C ⁻¹ *
^Expressed as B ^-1 .

As a result, assuming that the user repeats the printout of the reference signal and the photographing of the print image again in an attempt, as shown in FIG. 3B, the image data of the print image A * B ¹ * C ¹ Modified C in signal processing circuit 3
Receiving ^-1 * B ^-1 and canceling the modified B ¹ * C ¹ by the modified C ^-1 * B ^-1 , the characteristics and the like of the printer 20 are automatically corrected by the processing in the signal processing circuit 3. Therefore, image data equal to the reference signal A is obtained.

Therefore, when a still image obtained by photographing the original subject with the digital still camera 11 is printed out by the printer 20, deformation due to the photographing environment and the characteristics of the printer 20 is also caused by the signal processing circuit 3. , The characteristics of the printer 20 and the like are automatically corrected by the processing in the signal processing circuit 3, so that the image quality of the printed image becomes good.

In the above description, the operation has been described starting from the point where the reference signal is output. However, as another viewpoint, the operation will be described starting from the point where the print image is printed out. Print image (D)
But next D * C ¹ by receiving the deformation C ¹ in accordance with the color temperature or brightness, etc. of the illumination light, then modified by the signal processing circuit 3 C ^-1 * B by receiving ^-1 D * C ¹ * C ^-1 * B
^-1 = D * B ^-1 next, since the ^{D * B -1 * B 1 =} D by receiving the deformation B ¹ further printer 20, the results same printout is obtained with the original print image D as.

A specific example of the analysis result of the comparative analysis / characteristic control mechanism 8 and the adjustment of the characteristic of the signal processing circuit 3 based on the analysis result is as follows. (1) If the analysis result indicates that the hue is shifted by + 10 ° in the three-dimensional representation of color sensation as shown in FIG. 4, the hue is shifted by −10 °. (2) If the analysis result indicates that the color saturation is increased by 10%, the color saturation is reduced by 10%. (3) When the analysis result indicates that γ = 2.2, γ = 0.45 in γ correction. (4) If the analysis result indicates that the white balance is changing in the red direction, the sensitivity of blue is increased in white balance adjustment.

The original image of the subject undergoes a deformation opposite to the deformation caused by the shooting environment and the characteristics of the printer 20 in this manner.
Signal processing circuit 3 so as to give to the output signal of
By only adjusting the characteristics of the image data, the deformation of the image data due to the photographing environment and the characteristics of the printer 20 may be so complicated that the deformation of the image data is not completely canceled out. However, also in this case, the printer 20 is controlled by controlling the characteristics of the signal processing circuit 3 based on the analysis result of the comparative analysis and characteristic control mechanism 8 and adding other various elements as necessary. It is also possible to automatically correct the characteristics and the like by the processing in the signal processing circuit 3 to obtain a print image of good image quality.

As described above, according to the digital still camera 11, the printout of the reference signal is performed only once, and the printout of the reference signal is photographed. . Therefore, it is not necessary to prepare an expensive personal computer or retouching software and learn the operation as in the related art, or to waste time and print paper while changing printer settings. Thus, a print image with excellent image quality can be obtained.

In the above example, the setting operation is performed under the same photographing environment as when photographing the original subject.
However, as another example, in a digital still camera having a function that allows the user to adjust the white balance, setting operations are performed under a different shooting environment from when shooting the original subject, and when shooting the original subject, Alternatively, the user may adjust the white balance before shooting. In particular, when the original shooting location of the subject is outdoors, if the setting operation is performed indoors in advance, only the white balance adjustment needs to be performed outdoors, so the printer is carried outdoors. Time and effort can be saved.

In the above example, the comparative analysis / characteristic control mechanism 8 applies a reverse deformation to the image data to the CC.
The characteristics of the signal processing circuit 3 are controlled so as to be given to the output signal of the D imaging device 2. However, by causing the comparison analysis / characteristic control mechanism 8 to control the characteristics of the signal processing circuit 3 in a different form, the characteristics and the like of the printer 20 are automatically corrected by the processing in the signal processing circuit 3. You may.

In the above example, the comparison analysis / characteristic control mechanism 8 automatically sets the signal processing circuit 3 based on the analysis result.
Is controlled. But as another example,
For example, such an analysis result may be displayed on a monitor of a digital still camera, and the user may manually adjust the signal processing characteristics of the signal processing circuit 3 with an operation button on an operation panel while viewing the display.

Further, in the above example, as shown in FIG. 2, the reference signal of nine colors of a total of magenta M, cyan C, yellow Y, gray, white, black, red R, green G and blue B is used as the reference signal. A signal is used to obtain a printed image in which a portion of each color is arranged in a grid pattern. However, a signal that can obtain a printed image in another appropriate arrangement, or a color other than these colors is used. May be used as the reference signal.

In the above example, the present invention is applied to a digital still. However, it goes without saying that the present invention can be applied to an electronic still camera, a video camera or a scanner compatible with still images. In addition, the present invention is not limited to the above-described embodiments, and may take various other configurations without departing from the gist of the present invention.

[0039]

As described above, according to the still picture photographing apparatus of the present invention, the reference signal is printed out once.
By simply photographing a print image of this reference signal, a print image of good image quality can be obtained thereafter. Accordingly, a print image of good quality can be obtained inexpensively, easily and in a short time.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of a configuration of a digital still camera to which the present invention has been applied.

FIG. 2 is a diagram illustrating an example of a reference signal.

FIG. 3 is a diagram conceptually showing a state of deformation of a reference signal and the like.

FIG. 4 is a diagram showing an example of a three-dimensional expression of color sensation.

FIG. 5 is a block diagram showing a basic configuration of an existing digital still camera.

[Explanation of symbols]

Reference Signs List 1 lens, 2 CCD imaging device, 3 signal processing circuit, 4 memory, 5 interface, 6 reference signal memory, 7 switch, 8 comparative analysis / characteristic control mechanism, 10, 11 digital still camera, 20
Printer

Claims (2)

[Claims] 1. A still image photographing apparatus having a signal processing circuit for performing video signal processing on an output signal of an image sensor, wherein: a reference signal storage means for storing a printout reference signal including predetermined image information; A reference signal output unit that outputs the reference signal read from the signal storage unit as a signal to be printed out, and compares the image data generated by the signal processing circuit with the reference signal read from the reference signal storage unit. And
A stationary analyzing means for analyzing the deformation of the image data with respect to the reference signal; and a characteristic controlling means for controlling characteristics of the signal processing circuit based on an analysis result of the comparative analyzing means. Picture taking device. 2. The still image photographing apparatus according to claim 1, wherein the characteristic control unit is configured to change a characteristic of the signal processing circuit into a reverse of a deformation of the image data analyzed by the comparison analysis unit. A still image photographing apparatus characterized by controlling so as to give to an output signal of an image sensor.