JPH11122573A - Still image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly conduct photographing from a photographing operation till the end of a recording action and to prevent compression processing more than as required from being conducted to maintain the image quality by extracting still image information from an image pickup element continuously, calculating a compression rate of the still image information continuously and conducting compression processing to the still image information according to the compression rate calculated just before the photographing operation. SOLUTION: A microcomputer 6 executes a software program in a ROM 6a based on an operation signal from an operation input section 17. Still image information converted into digital data is once stored in a DRAM 5 and the microcomputer 6 starts signal compression processing. A compression rate is decided by extracting continuously the still image information from a CCD 11 and calculating the compression rate continuously based on the contents of the extracted still image information. Then, when the photographing operation is made, the microcomputer 6 conducts compression processing to the still image information according to the compression rate already decided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a still image pickup apparatus for converting a subject image into a digital signal and recording the digital signal on a recording medium in the form of still image information.

[0002]

2. Description of the Related Art Conventionally, there is a still image pickup apparatus which picks up a subject image formed by a taking lens by an image pickup device and records it as still image information. As an image pickup device, for example, a CCD (Charge) for extracting image information obtained by photoelectrically converting a subject image
ge Coupled Device) is used. In this still image pickup apparatus, the still image information is recorded on a recording medium such as a semiconductor memory (RAM) or a floppy disk.

[0003] In this still image pickup apparatus,
In order to enable more still image information to be recorded on a recording medium, a method has been proposed in which still image information is compressed and then recorded on a recording medium. Various types of signal compression processing have been proposed, and one of them is a standard called “JPEG”. It should be noted that how much signal compression is performed in such signal compression processing, that is, the compression ratio differs depending on the content of the still image information to be compressed.

[0004]

In the above-described still image pickup apparatus, when recording still image information on a recording medium, that is, after photographing a subject, compression processing is performed on the still image information to be recorded. Is going. The compression ratio at this time is not determined in advance, and is determined according to the content of the still image information during the compression process.

If the data amount of the still image information after the compression processing is larger than the remaining recording capacity on the recording medium even after the compression processing, an error message stating "recording is not possible" is displayed. Interrupt the recording process,
Alternatively, recording on a recording medium is performed after recompression processing is performed with a higher compression ratio. Such a maximum compression process may be repeatedly performed many times when the data amount of the still image information is large.

Therefore, in this still image pickup apparatus, the time required from the time when the photographing operation is performed to the time when the recording operation is completed becomes long. Further, since the compression processing is performed according to the remaining recording capacity of the loaded recording medium, the image quality of the recorded still image information may be degraded more than necessary.

Therefore, the present invention has been made in view of the above-mentioned circumstances, and can quickly perform the operations from the photographing operation to the completion of the recording operation. Further, depending on the contents of the still image, compression processing more than necessary is performed. It is an object of the present invention to provide a still image pickup device capable of maintaining the image quality of the recorded still image information while preventing the recording of the still image information.

[0008]

A still image pickup apparatus according to the present invention picks up an image formed by a photographing lens by an image pickup element, extracts still image information from the image pickup element, and compresses the still image information. A still image capturing apparatus that records still image information from an image sensor and continuously outputs the still image information based on the content of the still image information in order to solve the above-described problem. The compression ratio is continuously calculated, and when a shooting operation is performed, the still image information is compressed according to the compression ratio calculated immediately before the shooting operation is performed and recorded on a recording medium. is there.

Further, in this still image pickup device, the compression ratio can be corrected according to the correction value input via the input device, using the calculated compression ratio as a reference value.

[0010]

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

A still image pickup apparatus according to this embodiment obtains still image information by picking up an image of a subject formed by a photographic lens by an image pickup device, converts the still image information into a digital signal, and stores the information in a floppy disk as a recording medium. This is a device for recording on a computer. The floppy disk is, for example, a disk-shaped magnetic disk having a diameter of 3.5 inches, and is a magnetic recording medium rotatably housed in a cartridge and constituting a disk cartridge.

As shown in FIG. 1, this still image pickup device is a so-called image pickup device C, which photoelectrically converts a subject image formed by a photographing lens in field units and picks up an image.
And a CD (Charge Coupled Device) 11.
Still image information obtained by interlacing the CCD 11 for each field is sent to a sample / hold / analog-to-digital conversion circuit 12 that creates still image information based on the still image information. The sample hold / analog-to-digital converter 12 converts the sent still image information into 10-bit digital data and sends it to the camera signal processing circuit 13. This camera signal processing circuit 1
3 generates an 8-bit luminance signal Y and a 4-bit color difference signal C from the sent digital data, and sends them to the DRAM controller 14.

The DRAM controller 14 has a luminance signal Y
And the color difference signal C to the panel signal processing circuit 16. The panel signal processing circuit 16 includes a luminance signal Y and a color difference signal C.
The three primary color signals R, G, and B are generated and sent to an LCD (liquid crystal display) panel 15 serving as a display device. The LCD panel 15 outputs a C signal based on the transmitted three primary color signals R, G, and B.
The image captured by the CD 11 is displayed. LCD panel 15
The OSD (On Screen Display (On Screen Display) that can display characters on the LCD panel 15
een Display)) 4 is connected.

The DRAM controller 14 controls the DRAM 5 for storing still image information, and sends the still image information to the microcomputer 6 serving as a control circuit and a compression processing circuit, and an FDC (Floppy Disk Controller) 18. . The DRAM 5 includes a CCD 11
The still image information of the still image obtained based on the electric signal from the storage unit is stored. That is, the DRAM controller 14
DR converts the luminance signal Y and the color difference signal C from the camera signal processing circuit 13 based on the control of the microcomputer 6.
It is stored in a predetermined area of AM5. The DRAM 5 is, for example,
It is composed of two memory chips each having a capacity of 4 megabytes, so that it has a total storage capacity of 8 megabytes.

The FDC 18 controls an FDD (Floppy Display Drive) 19 by a control signal, and sends and receives write data RDATA and read data WDATA to and from the FDD 19.
In step D19, the still image information is written to and read from the floppy disk.

Then, the microcomputer 6 has the DR
AM controller 14, DRAM5, OSD4 and FD
Control C18. The microcomputer 6, the DRAM controller 14, the DRAM 5, the OSD 4
And the FDC 18 are connected to each other by a common bus.

The microcomputer 6 includes an RO
M6a is provided, and the operation input unit 17 is connected. The ROM 6a stores a software program for controlling each block. The operation input unit 17 has a selection button for selecting one of the field mode and the frame mode. The operation input unit 17 has various operation buttons / switches such as a shutter button, operation such as zooming, editing such as data deletion, and a selection button for selecting the above-described image capturing mode. The operation content of the operation button / switch is detected, and the detected signal is sent to the microcomputer 6 as an operation signal. As the microcomputer 6, for example, RISC (Res
A duced Instruction Set Computer (reduced instruction set computer) type is used.

In the still image pickup apparatus, the microcomputer 6 executes a software program in the ROM 6a based on an operation signal from the operation input unit 17, thereby allowing the microcomputer 6 to perform a static operation at the time of photographing, reproducing, and editing. Processing such as signal compression processing and signal decompression processing of image information and file management is performed.

The signal compression processing of the still image information in the microcomputer 6 is performed by a signal compression method according to the so-called "JPEG" standard. The still image information converted into digital data is temporarily stored in the DRAM 5 and the microcomputer 6 operating as a JPEG processor starts signal compression processing.

Here, the microcomputer 6 determines the compression ratio of the signal compression processing by continuously extracting still image information from the CCD 11 and determining the still image information based on the content of the extracted still image information. The calculation of the compression ratio is performed continuously. Then, when the photographing operation is performed, the microcomputer 6 performs the compression processing of the still image information according to the already determined compression ratio.

That is, as shown in FIG. 2, when a series of images (A) to (D) are continuously picked up by the CCD 11, the image shown in FIG. In this case, the optimal compression ratio for the image shown in FIG. 2C is determined from the compression ratio for the image shown in FIG. CC
Since the image taken by D11 should normally be continuous, the idea is that the compression ratio for the image of each frame will not change extremely on a continuous time axis.

It should be noted that the optimum compression ratio in the still image pickup device is to increase the compression ratio if the purpose is to record images of as many frames as possible on a recording medium having a fixed capacity. Conversely, if the image quality is prioritized over the number of frames, the compression ratio should be reduced as much as possible.

Here, the microcomputer 6 performs only the signal compression processing except at the time of actual shooting in order to shorten the processing time of the signal compression and not to use the capacity of the DRAM 5 more than necessary. , The compressed still image information is discarded.

In order to calculate the compression ratio in real time, the DRAM 5 is provided with two DRAM chips capable of storing one frame of still image information.
In this DRAM 5, two DRAM chips alternately take in still image information. That is, this DRAM
5, the microcomputer 6 has one of the DRAs
While the still image information is read from the M chip and the signal is compressed, the other DRAM chip takes in the still image information of the next frame. The operation of the DRAM 5 is controlled by the microcomputer 6 via the DRAM controller 14.

The microcomputer 6 which has calculated the compression ratio
Stores this value in the RAM in the microcomputer 6 and updates it every frame. When the still image information is actually recorded on the floppy disk, an optimum compression ratio is calculated based on the value of the compression ratio of one frame before, which is already stored in the RAM of the microcomputer 6, and a signal is calculated based on the compression ratio. Perform compression processing.

As shown in FIG. 3, the microcomputer 6 displays the calculated compression rate via the LCD panel 15 and uses the compression rate as a reference value via an operation input unit 17 serving as an input device. The compression ratio is corrected according to the correction value input by the user. That is, the microcomputer 6 calculates the compression ratio calculated in real time as O
It is displayed on the LCD panel 15 via SD4. Then, the user of this still image capturing apparatus sets the compression rate by increasing or decreasing the compression ratio by operating the increase / decrease key 17a on the operation input unit 17 based on the information displayed on the LCD panel 15, and then sets the data on the floppy disk. Can be recorded. At this time, if the remaining recording capacity of the floppy disk has room and the quality of the recorded image is to be high, the compression ratio may be reduced. Conversely, if there is no room for the remaining recording capacity of the floppy disk, or if the image quality of the image to be recorded is not important, the compression ratio may be increased.

When an operation to start shooting is performed, the microcomputer 6 performs signal compression processing at the calculated or corrected compression ratio, and converts the compressed still image information into
Once stored in the DRAM 5, the still image information is written to the floppy disk.

The compression ratio in the signal compression processing by the microcomputer 6 is to determine the amount of data that can be recorded from the remaining recording capacity of the floppy disk, and to automatically determine the compression ratio according to this data amount. It may be.

Further, in this still image pickup apparatus, based on the selection result of the image pickup mode by the selection button provided on the operation input unit 17, that is, the result of selecting between the field mode and the frame mode, One frame of still image information is created. That is, in the frame mode, one frame of still image information is created based on a plurality of fields of still image information. In the field mode, one frame of still image information is created as data corresponding to one frame based on the still image information of any one field.

Here, a field is a frame that constitutes one frame by a plurality, and the still image pickup device transmits an electric signal of the field unit from the CCD 11 by interlaced scanning in which the CCD 11 is scanned in units of the field. We are taking out. In this embodiment, one frame is composed of two fields, an ODD field, which is a field composed of odd-numbered scanning lines, and an EVEN field, which is a field composed of even-numbered scanning lines.

The still image pickup device has a flash lighting device 34. The flash lighting device 34 has at least one flash lighting unit, and operates under the control of the microcomputer 6. The flash illumination light emitting section of the flash illumination device 34 irradiates illumination toward the subject during the photoelectric conversion period for one field, and terminates the illumination before the photoelectric conversion for the next field. Have time. Therefore, the still image pickup device obtains effective still image information for one field by one light emission of any one of the flash illumination light emitting units of the flash illumination device 34 having the above-described flash time characteristics. Can be.

The flash illuminator of the flash illuminator 34 is constituted, for example, by using a strobe discharge tube which discharges a halogen gas enclosed in a so-called glass tube by applying a high voltage to obtain a flash. It has a capacitor for obtaining a high potential. As the halogen gas sealed in the glass tube, there is, for example, xenon gas.

In the still image pickup apparatus configured as described above, the microcomputer 6 includes the operation input unit 17
The operation of each block including the flash lighting device 34 is determined based on the selection result of the image capturing mode by the selection button of
The imaging by the CCD 11 is performed.

As shown in FIG. 4, the still image pickup apparatus configured as described above has a substantially rectangular parallelepiped outer shape and is configured to be portable. The outer housing 31 of the still image pickup device has a shutter button 3
2. A photographing lens 33 and a flash illumination device 34 are provided. The shutter button 32 can be pressed by a finger or the like of the user holding the still image pickup device.

On one side surface 35 of the outer casing 31 of the still image pickup device, a storage and mounting section 2 having an insertion opening 35a is provided. The storage mounting section 2 can be opened and closed by an opening and closing lid 3. The storage mounting section 2 is loaded with a disk cartridge 101 configured to store the floppy disk 100 therein from the side surface section 35 side. The disc cartridge 101 is mounted on the storage mounting section 2 such that the disc cartridge 101 is inserted from the shutter plate 101a side. An FDD 19 for writing and reading still image information and the like to and from the floppy disk 100 is provided in the storage mounting unit 2.
Are arranged.

In this still image pickup apparatus,
As shown in FIG. 5, an LCD panel 15 is provided on the rear side of the outer housing 31. At the time of shooting, a subject image is displayed on the LCD panel 15. Then, as described above, the microcomputer 6 always calculates the compression ratio based on the still image information constantly taken out from the CCD 11.

In this still image pickup apparatus,
When the subject is photographed by pressing the shutter button 32, the disc cartridge 1 loaded in the FDD 19 is
The still image information of the object photographed on the floppy disk 100 in the image No. 01 and the index image information of the still image information are signal-compressed and recorded.

At this time, the compression ratio of the still image information recorded on the floppy disk 100 is the compression ratio determined based on the compression ratio of the image taken immediately before the taken image, or this compression ratio. The compression ratio is corrected by a key operation on the operation input unit 17 based on the ratio.

In this still image pickup apparatus, L
Around the CD panel 15, various operation buttons and switches 36a, 36b, 36c, 36d, 36e, 36f, 3
6g and the like are provided, and by operating these various operation buttons and the like, operations relating to photography such as adjustment of the focal length of the photographing lens 33 during photography and operations such as editing of still image information can be performed. In addition, the selection operation between the field mode and the frame mode described above can be performed.

Further, the opening / closing of the opening / closing lid 3 is performed by the opening / closing operation section 3
7 is moved up and down so that the engaging claws 38a and 38b interlocked with the opening / closing operation portion 37 and the engaging portion 3
This is performed by releasing or holding the engagement state with a and 3b.

In the still image pickup apparatus thus configured, the subject can be photographed by pressing the shutter button 32. At this time, the optical signal from the subject is converted into an electric signal by the CCD 11, and the converted electric signal is interlaced and scanned to obtain one-field still image information. In the still image pickup device, when the flash lighting device 34 is used, by selecting the field mode, the still image information is obtained based on one field of still image information obtained by illuminating the flash lighting device 34. The still image information for one frame is generated, and the LCD panel 15 is generated based on the still image information.
The still image is displayed above.

[0042]

As described above, the still image pickup apparatus according to the present invention continuously extracts still image information from the image pickup device, and also performs the extraction of the still image information based on the contents of the still image information. The compression ratio is continuously calculated, and when a shooting operation is performed, the still image information is compressed according to the compression ratio calculated immediately before the shooting operation is performed.

In this still image pickup apparatus, the compression ratio can be corrected according to the input correction value, using the calculated compression ratio as a reference value.

That is, according to the present invention, from the photographing operation to the completion of the recording operation can be quickly performed, and depending on the content of the still image, the unnecessary compression processing is prevented from being performed. An object of the present invention is to provide a still image pickup device capable of maintaining image quality.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a still image capturing apparatus according to the present invention.

FIG. 2 is a front view showing an image which is always input to calculate a compression ratio in the still image capturing apparatus.

FIG. 3 is a front view showing display contents on a display device for correcting a compression ratio in the still image pickup device.

FIG. 4 is a perspective view showing the appearance of the still image pickup device as viewed from the front.

FIG. 5 is a perspective view showing the appearance of the still image pickup device as viewed from the back.

[Explanation of symbols]

6 microcomputer, 11 CCD, 17 operation input unit, 100 floppy disk, 101 disk cartridge

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor: Naomitsu Morita, Koda-cho, Nada-gun, Aichi Prefecture

Claims (2)

[Claims] 1. An image pickup device comprising: a photographing lens; and an image pickup device for picking up an image formed by the photographing lens. Still image information accumulated in the image pickup device is taken out by an image pickup operation of the image pickup device. A still image capturing apparatus for compressing the still image information and recording the still image information on a recording medium, wherein the still image information is continuously extracted from the image sensor, and the still image information is extracted based on the content of the extracted still image information. A control circuit for continuously calculating the compression ratio of the image data; a compression processing circuit for performing a compression process on the still image information in accordance with the compression ratio determined by the control circuit when a shooting operation is performed; Recording means for recording, on a recording medium, the still image information which has been subjected to the compression processing, and wherein the control circuit calculates the value immediately before the photographing operation is performed when the photographing operation is performed. The which was compression rate determined in the compression ratio for the compression of still picture information to be recorded on the recording medium, the still image capturing apparatus characterized by controlling the compression circuit. 2. The control circuit displays the calculated compression ratio via a display device, and corrects the compression ratio in accordance with a correction value input via the input device using the compression ratio as a reference value. The still image pickup apparatus according to claim 1, wherein: