JPH08181904A - Still camera - Google Patents

Abstract

PURPOSE: To select a compression rate with small power consumption at a high speed when the compression rate for data compression is automatically selected. CONSTITUTION: The still camera is provided with an image pickup section 25 picking up an image of an object to provide an output of analog image data, an A/D converter section 26 applying A/D conversion to the analog image data, an aperture 22 controlling an incident luminous quantity to the image pickup section 25 and a compression processing section 29 compressing image data from the A/D converter section 26 at a prescribed compression rate and also with a compression rate selection section 44 controlling a compression rate of the compression processing section 29 based on object distance by using a memory card 30 storing image data compressed by the compression processing section 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a still camera of a type in which a subject is imaged to obtain digital image data, the data is compressed and stored in a recording medium.

[0002]

2. Description of the Related Art FIG. 21 is a block diagram showing an example of a conventional still camera (hereinafter, may be abbreviated as "camera" as appropriate) in which an image of a subject is recorded as digital image data in a storage medium such as a memory card. It is a figure. The camera shown in FIG. 21 starts an imaging operation by half-pressing a release button (not shown). First, light from a subject passes through the lens 1, is controlled to have an appropriate amount of light by the diaphragm 2, and then is imaged on the image pickup unit 5 via the mirror optical system 3 and the electronic shutter 4. The light from the subject is photoelectrically converted by the image pickup unit 5, converted into digital data by the A / D conversion unit 6, and input to the signal processing unit 7. The signal processing unit 7 subjects the digital data to certain signal processing such as white balance correction, amplification, γ correction, and edge enhancement, and outputs an image signal. The image signal is temporarily stored in the buffer memory 8.

The image signal data stored in the buffer memory 8 is sent to the compression processing section 9 by the full-press operation of the release button, and after the known data compression processing is performed by the compression processing section 9, the memory card 10 is processed. It is stored in a memory (not shown).

The mirror optical system 3 also guides the subject light to the focus detection section 15 and the photometry section 16. The focus detection unit 15 detects the focus state based on the subject light and outputs the detection result to the control unit 20. The photometric unit 16 performs photometry on the subject light and outputs the photometric result to the control unit 20.

The control unit 20 controls each of the above-mentioned units.
In addition, the control unit 20 includes the focus detection unit 15 and the photometry unit 16
The calculation for focusing and proper exposure is performed based on the detection result input from the lens 1, and the lens 1, the diaphragm 2, and the shutter 4 are controlled based on the calculation result. This provides autofocus and autoexposure.

The camera shown in FIG. 21 has two modes, a compression manual mode and a compression auto mode. When shooting in the compression manual mode, the photographer can select a compression coefficient for data compression by the compression processing section 9, Data compression is performed according to the selected compression coefficient. on the other hand,
When capturing images in compressed auto mode, the buffer memory 8
Depending on the characteristics of the digital image data stored in the device or extracting some image data and operating the compression circuit, the camera side selects an appropriate compression ratio from the data length at that time, and the selected compression ratio Data compression is performed by.

As a method of automatically selecting the compression rate, for example, as disclosed in Japanese Patent Laid-Open No. 3-205963, data compression processing of digital image data is actually performed at an appropriate compression rate, and the data amount after compression is increased. There is a method of selecting a compression coefficient that minimizes the amount of data or the amount of data after compression is always constant.

[0008]

However, in the conventional still camera described above, when the photographer selects the compression auto mode, the digital image data stored in the buffer memory 8 is actually analyzed to determine the compression ratio. Since the configuration is such that the compression rate is selected or the data compression process is actually performed on the digital image data in the buffer memory 8, it takes a long time to select an appropriate compression rate. For this reason, it takes a long time from the start of the photographing operation until the data is stored in the memory card 8, which is a factor that prevents the continuous shooting from being speeded up. Further, since the data analysis circuit and the compression circuit are operated to select the compression rate, the power consumption is large.

An object of the present invention is to provide a still camera capable of selecting a compression rate at low power consumption and high speed when automatically selecting a compression coefficient for data compression.

[0010]

[Means for Solving the Problems] Description will be made in association with FIG. The present invention comprises image pickup means (25, 26) for picking up a subject image and outputting digital image data, and data compression means 29 for compressing the image data from the image pickup means (25, 26) at a predetermined compression rate. Provision and compression means 29
The present invention is applied to a still camera configured to store the image data compressed by the recording medium 30. According to the first aspect of the invention, the above object is achieved by including the compression rate control means (40, 44) for calculating and controlling the compression rate of the data compression means 29 based on at least the distance to the subject. Description will be made in association with FIG. 7, which is an example. In the invention of claim 5, the above object is achieved by including the compression rate control means (40A, 44A) for calculating and controlling the compression rate of the data compression means 29 based at least on the focal length of the taking lens 21. . Description will be made in association with FIG. 13 which is an example. According to the invention of claim 9, the compression ratio control means (40B, 44B) for calculating and controlling the compression ratio of the data compression means 29 based on at least the distance to the subject and the focal length of the taking lens 21 is provided. The above object is achieved. Description will be made in association with FIG. 17, which is an example. In the thirteenth aspect of the present invention, the compression ratio control means for calculating and controlling the compression ratio of the data compression means 29 based on at least the distance to the subject, the focal length of the taking lens 21, and the aperture value of the aperture means 22 ( 40C, 44C)
By including, the above-mentioned object is achieved. It is preferable to determine the compression rate according to the settings of the image quality priority mode and the data length priority mode.

[0011]

According to the invention of claim 1, the compression ratio is calculated based on at least the distance to the subject. In the invention of claim 5, the compression ratio is calculated based on at least the focal length of the taking lens. In the invention of claim 9, the compression ratio is calculated based on at least the distance to the subject and the focal length of the photographing lens. In the thirteenth aspect of the invention, the compression ratio is calculated based on at least the distance to the subject, the focal length of the photographing lens, and the aperture value of the aperture means. The farther the shooting distance, the shorter the focal length, and the larger the aperture value, the larger the amount of data of each captured image.In image quality priority mode, the compression ratio is lowered to give priority to image quality, and in data length priority mode, the data amount is reduced. In order to keep the length almost constant, the compression rate is increased when the data amount is large, and the compression rate is decreased when the data amount is small.

In the means and means for solving the above problems which explain the constitution of the present invention, the drawings of the embodiments are used for easy understanding of the present invention. However, the present invention is not limited to this.

[0013]

【Example】

(Selection of compression ratio by shooting distance) FIG. 1 is a block diagram showing an embodiment of a still camera according to the present invention. The still camera of this embodiment, like the conventional camera described above, has a lens 21, a diaphragm 22, a mirror optical system 23, and a shutter 24, an imaging unit 25 on which light from a subject (not shown) is focused, and A / D conversion unit 26, signal processing unit 27 that performs signal processing such as γ correction, buffer memory 28 that temporarily stores image data, compression processing unit 29 that performs data compression processing, and image data recording Memory card 3
0, a focus detection unit 35 and a photometric unit 36, and a control unit 40 including a microprocessor and the like for controlling each circuit.

The image pickup unit 25 of the present embodiment is provided with an image pickup device such as a CCD, converts light from a subject imaged on the image pickup device into electric signals at predetermined intervals, and outputs analog signals in screen (frame) units. Output in image data format.

The compression processing unit 29 performs well-known quantization operation and code assignment operation on the digital image data,
Performs compression calculation of image data. The compression processing unit 29 has a plurality of quantization tables for the quantization operation, specifically, three quantization tables, and by selecting one of the quantization tables, the final data compression is performed. The rate is fixed. Hereinafter, the three compression rates corresponding to the selected quantization table will be referred to as a low compression rate (L), a medium compression rate (M), and a high compression rate (H), respectively.

Reference numeral 41 is a half-push switch that is turned on by a half-push operation of a release button (not shown), and 42 is a full-push switch that is turned on by a full-push operation of the release button. Reference numeral 43 denotes a mode setting switch. When the mode setting switch 43 is turned on, the image quality priority mode is instructed, and when it is turned off, the data length priority mode is instructed.

In the image quality priority mode, the image quality of the subject image captured by the image capturing unit 25 is stored as much as possible, that is, the image quality is emphasized and the compressed image is stored in the memory card 30, and the image data of high image quality is reproduced. In this mode, the image quality is as high as possible. Therefore, since high-quality image data is compressed at a low compression rate and stored in the memory card 30, the image data length of one screen is not constant. On the other hand, the data length priority mode is a mode in which the image data length of one screen is stored as constant as possible in the memory card 30 regardless of the image quality of the subject image captured by the image capturing unit 25. Therefore, even high-quality image data may be compressed and stored at a high compression rate, and the image quality of the reproduced image data may deteriorate.

Reference numeral 44 denotes a compression rate selecting section equipped with a microprocessor or the like, which selects one of a low compression rate, a medium compression rate and a high compression rate in accordance with the photographing distance, and the quantum of the compression processing section 29. The control unit 40 sends a command signal for selecting the conversion table.
Send to. In the present embodiment, a lens encoder 52 that detects the lens position of the taking lens 21 is provided, and the lens position detected by this lens encoder 52 is used as the compression ratio selection unit 4.
4 to calculate the shooting distance. Lens encoder 5
Instead of 1, a distance measuring device may be provided to directly measure the shooting distance. Details of selection of the compression ratio will be described later.

Next, the operation of the camera of this embodiment will be described with reference to the flow charts of FIGS. 2 to 4 and FIG. The program shown in FIG. 2 starts when a release button (not shown) is half-pressed to turn on the half-press switch 41. First, in step S201, the photometric unit 36 performs a photometric operation on the subject light guided to the photometric unit 36 by the mirror optical system 23. The photometric result is input to the control unit 40. Similarly, in step S202, the focus detection unit 35 performs a focus state detection operation on the subject light guided to the focus detection unit 35 by the mirror optical system 23, and the control unit 40 detects the focus detection unit 35. The lens 21 is driven so that a focused state is obtained based on the result.
In step S211, the shooting distance from the lens position to the subject is calculated.

Next, in step S203, it is determined whether or not the full press switch 42 is turned on, and the switch 4
2 is in the ON state, the program proceeds to step S204, and if the switch 42 is in the OFF state, the program proceeds to step S2.
Move to 09. In step S209, it is determined whether the half-push switch 41 is turned on, and the switch 41
If is turned on, the process returns to step S201, and if the switch 41 is turned off, waits for a fixed time between step S210 and step S209. If the half-push switch 41 is not turned on during this fixed time, the program ends. .

In step S204, step S201
The control unit 40 controls the aperture value of the aperture 22 based on the result of the photometric operation performed in step S <b> 2, and further, in step S <b> 205, the control unit 40 controls the drive of the shutter 44. In step S206, a compression rate selection operation is performed. In a camera in which the program mode can be set, the shutter speed and the aperture value are calculated from the brightness detected by the photometry unit 36 using one program diagram selected from a plurality of program diagrams stored in advance. It In aperture priority mode and manual mode, the manually input aperture value is calculated, and in shutter priority mode,
The aperture value is determined based on the brightness and the input shutter speed.

FIG. 3 is a flow chart showing the details of the compression rate selection operation. The program shown in this flow chart is executed by the compression rate selection unit 44. Step S30
In 1, the compression rate selection unit 44 reads the shooting distance. Next, in step S302, the on / off state of the mode setting switch 43 is read via the control unit 40. As a result, when the switch 43 is on and the image quality priority mode is set, the program proceeds to step S303,
When the switch 43 is off and the data length priority mode is set, the process proceeds to step S308.

In step S303, step S301
It is determined whether or not the shooting distance read in is a value equal to or larger than a predetermined constant d _{L. If} the determination is affirmative, the process proceeds to step S305, and if the determination is negative, the step S305 is performed.
Move to 304. In step S304, step S
The shooting distance read in step 301 is a predetermined constant d
_It is determined whether or not it is larger than _s (<d _L ), and if the determination is negative, the process proceeds to step S307, and if the determination is affirmative, the process proceeds to step S306.

In step S305, a low compression rate L is selected, and a command signal for selecting a quantization table for realizing this low compression rate L is sent to the control unit 40. In step S306, the medium compression rate M is selected, and this medium compression rate M
A command signal for selecting a quantization table for realizing is transmitted to the control unit 40. In step S307, the high compression rate H is selected, and a command signal for selecting a quantization table for realizing this high compression rate H is sent to the control unit 40. The above is summarized in the table shown in FIG.

FIG. 4 is a flow chart showing the details of the compression rate selection operation in the data length priority mode, which is also executed by the compression rate selection unit 44. First, in steps S401 and S402, operations similar to S303 and S304 in the flowchart shown in FIG. 3 are performed. Then, if the determination in step S401 is affirmative, the process proceeds to step S403, the high compression rate H is selected, and the command signal for selecting the quantization table for realizing the high compression rate H is the control unit 40. Sent to. When the determination in step S402 is negative, the process proceeds to step S405, the low compression rate L is selected, and the command signal for selecting the quantization table for realizing the low compression rate L is the control unit 40. Sent to. Furthermore, if the determination in step S402 is affirmative, step S402
Moving to 404, the medium compression rate M is selected, and at the same time, a command signal for selecting the quantization table for realizing the medium compression rate M is sent to the control unit 40. The above is summarized in the table shown in FIG.

As described above, in the image quality priority mode, a lower compression ratio is selected as the shooting distance becomes longer, and conversely, in the data length priority mode, a higher compression ratio is selected as the shooting distance becomes longer. As the shooting distance becomes longer, the depth of field becomes deeper, and many parts are in focus and an image with a large amount of data can be obtained. Therefore, in image quality priority mode, there is a large amount of data so that an image faithful to the subject can be obtained during playback. The operation of reducing the compression rate for image data is performed. On the other hand, the larger the amount of data is, the longer the data length after compression is. Therefore, in the data length priority mode, the image data having a large amount of data is stored so that the data length of one screen stored in the memory card 30 is as constant as possible. To increase the compression ratio.

Returning to FIG. 2, in step S207, the compression processing unit 29 executes data compression processing on the image data stored in the buffer memory 27 at the compression rate selected in step S206, and in step S208, data compression is performed. The generated image data is stored in the memory (not shown) of the memory card 30.

Therefore, according to the present embodiment, since the compression rate is automatically selected according to the photographing distance, the compression circuit is operated depending on the characteristics of the digital image data or a part of the image data is extracted. Compared to the conventional camera that selected the compression rate of data compression from the data length at that time,
The compression rate selection work can be performed at high speed. As a result, the time from the start of the shooting operation to the storage of the image data in the memory card can be shortened as compared with the conventional case, and high-speed continuous shooting becomes possible. Also, an A / D converter for selecting the compression ratio,
Since it is not necessary to operate the buffer memory and the compression circuit, no power is wasted.

(Selection of compression ratio by focal length) FIGS. 7 to 10
9 is a block diagram and a flowchart of a still camera according to another embodiment in which a compression rate is selected according to a focal length. When the taking lens 21 is a zoom lens, as shown in FIG. 7, a zoom encoder 51 for detecting the focal length of the taking lens 21 is provided, and the focal length detected by the zoom encoder 51 is provided to the compression rate selecting unit 44A. Supply.

FIG. 8 is a flowchart corresponding to FIG. 2. In step S211A, the focal length f is read from the zoom encoder 51. Others are the same as those in FIG. 2, and the same reference numerals are given and description thereof is omitted. 9 and 10 are flowcharts corresponding to FIGS. 3 and 4. 9 and 10 are different from FIGS. 3 and 4 in that the photographing distance is replaced by the focal length, d _L is replaced by f _L , and d _S is replaced by f _S. In the image quality priority mode, when the focal length is less than or equal to the lower limit value f _S , a low compression rate is selected in step S305A, and when it is an intermediate value between the upper limit value f _L and the lower limit value f _S , medium compression is performed in step S306A. Select the rate and the upper limit value f _L
In the above case, a high compression rate is selected in step S307A. The above is summarized in the table of FIG.

In the data length priority mode, if the focal length is less than or equal to the lower limit value f _S , a high compression rate is selected in step S403A, and if it is an intermediate value between the upper limit value f _L and the lower limit value f _S , the step is performed. The medium compression ratio is selected in S404A, and the upper limit value f
_{If L} or more, a low compression rate is selected in step S405A. The above is summarized as shown in FIG.

As described above, in the embodiments shown in FIGS. 7 to 10, in the image quality priority mode, the lower the focal length is, the lower the compression ratio is selected. On the contrary, in the data length priority mode, the shorter the focal length is, the higher the compression ratio is. Has been selected. This is because the shorter the focal length, the higher the range of subjects that can be captured on the screen, resulting in an image with a large amount of data, and the deeper depth of field that allows more parts to be in focus. In the mode, an operation of lowering the compression rate is performed for image data having a large amount of data so that an image faithful to the subject can be obtained during reproduction. On the other hand, the larger the amount of data, the longer the data length after compression. Therefore, in the data length priority mode, image data with a large amount of data is stored so that the data length of one screen stored in the memory card 30 is as constant as possible. On the other hand, the operation of increasing the compression rate is performed.

(Selection of compression ratio based on shooting distance and focal length) In the above, the compression ratio is selected only according to the shooting distance, or the compression ratio is selected only according to the focal length. The compression rate may be selected according to each combination. FIG. 13 is a block diagram of an example of such a still camera, and the same parts as those in FIGS. 1 and 7 are designated by the same reference numerals to describe the differences. Compression rate selection unit 4
4B, the lens position of the photographing lens 21 is supplied from the lens encoder 52, and the focal length is supplied from the zoom encoder 51, and the compression rate selecting unit 44B calculates the photographing distance from the lens position. The data compression processing unit 29 is controlled by calculating the compression ratio according to the focal length.

FIG. 14 is a main flowchart of this embodiment and corresponds to FIGS. 2 and 8. 2 and 8
The same reference numerals are given to the same portions as, and the differences will be described. In step S211B, the shooting distance and the focal length are detected. In step S206B, based on the photographing distance and the focal length detected in step S211B, as shown in FIGS.
An appropriate compression rate is calculated with reference to the table as shown in FIG.

FIG. 15 shows a table for selecting the compression ratio by the combination of the shooting distance and the focus adjustment in the image quality priority mode, and FIG. 16 shows the table by which the compression ratio is selected by the combination of the shooting distance and the focal length in the data length priority mode. Represents a table. 15 and 16, f1, f2, f
3, d1, d2, and d3 are as follows, respectively.

F1 <50 mm, 50 mm ≦ f2 ≦ 120
mm, 120 mm <f3 d1 <50 cm, 50 cm ≦ d2 ≦ 100 cm, 100
cm <d3

(Selection of compression ratio based on shooting distance, focal length and aperture value) The compression ratio may be selected according to the combination of the shooting distance, the focal length and the aperture value. FIG. 17 is a block diagram of an example of such a still camera, and the same parts as those in FIGS. 1, 7 and 13 are designated by the same reference numerals to describe the differences. The compression ratio selection unit 44C is supplied with the aperture value from the diaphragm 22, the lens position of the taking lens from the lens encoder 52, and the focal length from the zoom encoder 51, respectively, and the compression ratio selection unit 44C obtains the shooting distance from the lens position. The data compression processing unit 29 is calculated by calculating the compression rate according to the calculated shooting distance, focal length, and aperture value.

FIG. 18 is a main flow chart of this embodiment and corresponds to FIGS. 2, 8 and 14. Figure 2
The same parts as those in FIGS. 8 and 14 are designated by the same reference numerals to describe the differences. In step S211C, the shooting distance, focal length, and aperture value are detected. In step S206C,
Referring to the tables of FIGS. 19 and 20, based on the shooting distance, the focal length, and the aperture value detected in step S211C,
Calculate an appropriate compression ratio.

FIG. 19 shows a table for selecting the compression ratio from the combination of the shooting distance, the focal length and the aperture value in the image quality priority mode, and FIG. 20 shows the shooting distance, the focal length and the aperture value in the data length priority mode. The table for selecting the compression rate from the combination of 19 and 20.
, F1, f2, f3, d1, d2, d3, F
1, F2 and F3 are as follows, respectively.

F1 <50 mm, 50 mm ≦ f2 ≦ 120
mm, 120 mm <f3 d1 <50 cm, 50 cm ≦ d2 ≦ 100 cm, 100
cm <d3 F1 <2.8, 2.8 ≦ F2 ≦ 5.6, 5.6 <F3

In the correspondence between the embodiments described above and the claims, the image pickup unit 25 and the A / D conversion unit 26 serve as the image pickup means, the diaphragm 22 serves as the diaphragm means, the compression processing portion 29 serves as the data compression means, and the memory. The card 30 is a recording medium, and the control unit 4
0, 40A, 40B, 40C and compression rate selection units 44, 44
A, 44B and 44C correspond to the compression ratio control means, and the compression mode setting switch 43 corresponds to the image quality priority mode setting means, the data length priority mode setting means and the compression mode setting means.

The details of the still camera of the present invention are not limited to the above-described embodiment, and various modifications are possible. As an example, in one embodiment, the compression rate is divided into three stages for automatic selection, but the automatic selection may be divided into the same number of stages as the number of diaphragm stages, or the compression ratio is linearly determined. You may change continuously. Further, in one embodiment, the quantization tables are prepared for the compression rate stages.
The compression rate may be changed by changing the weighting for one quantization table. Further, in the embodiment, all the compression ratios are automatically selected, but a compression mode switch and a compression ratio manual selection switch may be provided to allow the photographer to select the compression manual mode or the compression auto mode.

Note that the description of one embodiment is for so-called single-shot shooting, in which image data is stored in the memory card one screen at a time, but in the case of continuous shooting, the photometering section and the diaphragm are not operated during the shooting operation. Since it is operated and controlled, the above-described automatic compression ratio selection operation can be performed even during continuous shooting. Alternatively, the compression rate may be fixed during continuous shooting.

[0044]

As described in detail above, according to the present invention, the compression rate of the data compression means is controlled according to the photographing distance, or the compression rate is controlled according to the focal length.
The compression rate selection work can be performed at a higher speed than the conventional still camera. As a result, the time from the start of the shooting operation to the storage of the recording medium can be shortened as compared with the conventional case, and high-speed continuous shooting becomes possible. In addition, since it is not necessary to operate the compression circuit or the like for selecting the compression ratio, power consumption is not wasted. The compression ratio is controlled according to the shooting distance and the focal length like the still camera according to claims 9 to 12, or the compression ratio is controlled according to the shooting distance, the focal length and the aperture value like the still camera according to claims 13 to 15. If the ratio is controlled, finer compression ratio control becomes possible.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a still camera according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the still camera according to the embodiment.

FIG. 3 is a flowchart illustrating details of a compression rate selection operation according to an embodiment.

FIG. 4 is a flowchart for explaining details of a compression rate selection operation in a data length priority mode according to an embodiment.

FIG. 5 is a diagram illustrating a compression rate selected in an image quality priority mode according to a shooting distance.

FIG. 6 is a diagram illustrating a compression rate selected in a data length priority mode according to a shooting distance.

FIG. 7 is a block diagram showing a configuration of a still camera according to a second embodiment of the present invention.

FIG. 8 is a flowchart for explaining the operation of the still camera according to the second embodiment.

FIG. 9 is a flowchart for explaining details of a compression rate selection operation in the second embodiment.

FIG. 10 is a flowchart for illustrating details of a compression rate selection operation in a data length priority mode of the second embodiment.

FIG. 11 is a diagram illustrating a compression rate selected in an image quality priority mode according to a focal length.

FIG. 12 is a diagram illustrating a compression rate selected in a data length priority mode according to a focal length.

FIG. 13 is a block diagram showing a configuration of a still camera according to a third embodiment of the present invention.

FIG. 14 is a flowchart for explaining the operation of the still camera according to the third embodiment.

FIG. 15 is a diagram illustrating a compression rate selected in an image quality priority mode according to a shooting distance and a focal length.

FIG. 16 is a diagram illustrating a compression rate selected in a data length priority mode according to a shooting distance and a focal length.

FIG. 17 is a block diagram showing the structure of a still camera according to a fourth embodiment of the present invention.

FIG. 18 is a flowchart for explaining the operation of the still camera according to the fourth embodiment.

FIG. 19 is a diagram illustrating a compression rate selected in an image quality priority mode according to a shooting distance, a focal length, and an aperture value.

FIG. 20 is a diagram illustrating a compression rate selected in a data length priority mode according to a shooting distance, a focal length, and an aperture value.

FIG. 21 is a block diagram showing a configuration of a conventional still camera.

[Explanation of symbols]

 21 Photographic lens 22 Aperture 25 Imaging unit 26 A / D conversion unit 28 Buffer memory 29 Compression processing unit 30 Memory card 35 Focus detection unit 36 Photometric unit 40, 40A, 40B, 40C Control unit 44, 44A, 44B, 44C Compression ratio selection Part 51 Zoom encoder 52 Lens encoder

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 7/24 H04N 7/13 Z

Claims (16)

[Claims] 1. An image pickup unit for picking up a subject image through a taking lens to output digital image data, and a data compression unit for compressing image data from the image pickup unit at a predetermined compression ratio. A still camera configured to store image data compressed by means in a recording medium, comprising a compression rate control means for calculating and controlling a compression rate of the data compression means based on at least the distance to the subject. Still cameras that are characterized. 2. The still camera according to claim 1, further comprising image quality priority mode setting means for setting an image quality priority mode for compressing the image data by emphasizing image quality of a subject image captured by the image capturing means. The still camera, wherein when the image quality priority mode is set, the compression rate is lowered as the shooting distance increases. 3. The still camera according to claim 1, wherein a data length is set to a data length priority mode for compressing the image data so that the data length of the image data recorded on the recording medium becomes substantially constant. A still camera, further comprising a priority mode setting means, wherein when the data length priority mode is set, the compression rate is increased as the shooting distance increases. 4. The still camera according to claim 1, wherein an image quality priority mode in which the image data is compressed by emphasizing an image quality of a subject image captured by the image capturing unit, and the image recorded in the recording medium. A compression mode setting means for setting a data length priority mode for compressing the image data so that the data length of the data becomes substantially constant is further provided, and in the case where the image quality priority mode is set, as the shooting distance becomes longer, A still camera, wherein when the compression rate is low and the data length priority mode is set, the compression rate is increased as the shooting distance increases. 5. An image pickup means for picking up a subject image through a taking lens and outputting digital image data, and a data compressing means for compressing image data from the image pickup means at a predetermined compression ratio. A still camera configured to store image data compressed by a recording medium in a recording medium, comprising a compression ratio control unit for calculating and controlling a compression ratio of the data compression unit based on at least a focal length of the photographing lens. Still camera that is characterized. 6. The still camera according to claim 5, further comprising image quality priority mode setting means for setting an image quality priority mode for compressing the image data by emphasizing image quality of a subject image captured by the image capturing means. The still camera, wherein when the image quality priority mode is set, the compression rate is lowered as the focal length becomes shorter. 7. The still camera according to claim 5, wherein the data length is set to a data length priority mode for compressing the image data so that the data length of the image data recorded on the recording medium becomes substantially constant. A still camera, further comprising a priority mode setting means, wherein when the data length priority mode is set, the compression rate is increased as the focal length becomes shorter. 8. The still camera according to claim 5, wherein an image quality priority mode in which the image data is compressed by emphasizing the image quality of a subject image captured by the image capturing means, and the image recorded in the recording medium. A compression mode setting means for setting a data length priority mode for compressing the image data so that the data length of the data becomes substantially constant is further provided, and when the image quality priority mode is set, the shorter the focal length becomes, A still camera, wherein when the compression rate is low and the data length priority mode is set, the compression rate is increased as the focal length becomes shorter. 9. An image pickup means for picking up a subject image through a taking lens and outputting digital image data, and a data compressing means for compressing image data from the image pickup means at a predetermined compression ratio. In a still camera configured to store image data compressed by a recording medium in a recording medium, a compression ratio of the data compression unit is calculated and controlled based on at least a distance to the subject and a focal length of the photographing lens. A still camera, which is provided with a compression rate control means for controlling the compression rate. 10. The still camera according to claim 9, further comprising image quality priority mode setting means for setting an image quality priority mode for compressing the image data by emphasizing image quality of a subject image captured by the image capturing means. The still camera, wherein when the image quality priority mode is set, the compression rate is lowered as the shooting distance becomes longer and the focal length becomes shorter. 11. The still camera according to claim 9, wherein a data length is set to a data length priority mode for compressing the image data so that the data length of the image data recorded on the recording medium becomes substantially constant. A still camera, further comprising priority mode setting means, wherein when the data length priority mode is set, the compression rate is increased as the shooting distance becomes longer and the focal length becomes shorter. 12. The still camera according to claim 9, wherein an image quality priority mode in which the image data is compressed by emphasizing the image quality of a subject image captured by the image capturing unit, and the image recorded in the recording medium. A compression mode setting means for setting a data length priority mode for compressing the image data so that the data length of the data becomes substantially constant is further provided, and in the case where the image quality priority mode is set, as the shooting distance becomes longer, , And the compression rate decreases as the focal length decreases, and when the data length priority mode is set, the compression rate increases as the shooting distance increases and the focal length decreases. A still camera. 13. An image pickup unit for picking up an image of a subject through a taking lens and outputting digital image data, a diaphragm unit for adjusting an amount of light incident on the image pickup unit, and image data from the image pickup unit to a predetermined value. A still camera, comprising: a data compression unit for compressing at a compression rate, wherein the image data compressed by the compression unit is stored in a recording medium, wherein a distance to a subject, a focal length of the photographing lens, and the diaphragm unit. A still camera, comprising: a compression rate control means for calculating and controlling a compression rate of the data compression means based on at least the aperture value. 14. The still camera according to claim 13, further comprising image quality priority mode setting means for setting an image quality priority mode for compressing the image data by emphasizing image quality of a subject image captured by the image capturing means. A still camera, wherein when the image quality priority mode is set, the compression rate is lowered as the shooting distance becomes longer, the focal length becomes shorter, and the aperture value becomes larger. 15. The still camera according to claim 13, wherein the data length is set to a data length priority mode for compressing the image data so that the data length of the image data recorded on the recording medium becomes substantially constant. When the data length priority mode is set, a further priority mode setting means is provided, and as the shooting distance becomes longer and the focal length becomes shorter,
A still camera, wherein the compression rate is increased as the aperture value is increased. 16. The still camera according to claim 13, wherein an image quality priority mode in which the image data is compressed by emphasizing an image quality of a subject image captured by the image capturing unit, and the image recorded in the recording medium. A compression mode setting means for setting a data length priority mode for compressing the image data so that the data length of the data becomes substantially constant is further provided, and in the case where the image quality priority mode is set, as the shooting distance becomes longer, When the focal length is shorter and the aperture value is larger, the compression rate is lower, and when the data length priority mode is set, the longer the shooting distance, the shorter the focal length, and the aperture. A still camera characterized in that the higher the value, the higher the compression rate.