JPH05110979A - Picture recorder - Google Patents

Abstract

PURPOSE:To efficiently record picture data by constituting a picture recorder so that the picture obtained by the expansion processing corresponding to an arbitrarily set compression rate can be reproduced and monitored. CONSTITUTION:When an object is photographed and compressed data is obtained, a switch 18 is set to the connection state shown by a continuous line, and picture data compressed with the compression rate prescribed by a compression parameter part 14 at present is recorded in a memory 8. Compressed data read out from the memory 8 is supplied to a data compressing/ expanding part 7 and is subjected to the expansion processing in the expansion mode corresponding to the compression rate and is subjected to inverse orthogonal conversion by an orthogonal conversion/inverse orthogonal conversion part 6 and is recorded in a frame memory 5. Expanded data read out from the frame memory 5 is mixed with some information, which indicates that the present compression result generated from a system controller 15 is displayed, by a MIX part 20 and is converted to an analog signal by a D/A converter 13 and is outputted to an ECF/display part 17 or the like controlled by the system controller 15.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus,
In particular, the present invention relates to an image recording apparatus that enables setting of an optimum compression rate when image data is compressed and recorded in a memory. 2. Description of the Related Art An electronic still camera is an application example of an image recording apparatus for compressing image data and recording it in a memory. An electronic still camera uses a memory card such as an IC card as a recording medium for recording an optical image instead of a silver salt film, and performs recording, reading and reproduction through electrical processing such as predetermined digital processing. Attention has been paid to the ease of processing and the ease of various types of processing for images. In the image recording and reproduction processing of this kind of camera, at the time of recording, a subject image (optical image) that has passed through an optical system such as a lens
An image is formed on a photoelectric conversion element such as a CCD and converted into an electric signal (image data), and the obtained image data is subjected to DCT.
Performs orthogonal transform processing such as (Discrete Cosine Transform) and records it as compressed data on a memory card, and when reproducing a subject image as a still image, inverse orthogonal transform processing is performed on the image data read from the memory card. The compressed image data is expanded to reproduce the subject image. If the compression rate of the image data is increased, the number of frames that can be recorded in the memory increases, but the image quality deteriorates. On the other hand, if the compression rate is lowered, the image quality is improved but the number of recordable frames is reduced. By the way, there are various kinds of subject images, from a monotone screen with little change to a complex screen with great change, and when a monotonous screen is photographed and recorded, the reproduced image quality is high even if the compression ratio is high. The deterioration is not so noticeable. But,
In the case of shooting and recording a complicated screen, the image quality of the playback screen deteriorates significantly unless the compression rate is lowered. Therefore, Japanese Patent Laid-Open No. 2-3
No. 05189 proposes a still video camera in which various compression methods can be selected by an external signal and an appropriate compression method can be set according to a subject image.
Japanese Patent Laid-Open No. 2-105686 discloses a digital recording of a still image in which a plurality of types of compression ratios can be selectively set and a desired image quality mode can be set by selecting an appropriate compression ratio according to a subject image. A device is disclosed. As described above, in a conventional image recording apparatus such as an electronic still camera, a plurality of types of compression methods can be selected and set, and an operator can select an arbitrary compression method (compression ratio). Some are configured to allow you to select. However, for example, in an electronic still camera, when the compression rate is changed in consideration of the subject image, a predetermined compression rate is selected and set by the intuition of the operator. Is the selected compression rate optimal? It is not possible to know whether or not the captured image data is compressed and recorded in the memory, the compressed image data is read from the memory, decompressed, and then played back until the actual image quality corresponding to the compression ratio is reached. I cannot confirm the condition. Therefore, if a high compression rate is set with the intention of saving the memory capacity too much, only a low-quality playback screen can be obtained for the important subject image. Further, if a low compression rate is set in order to avoid such a situation, there is a problem that a large memory recording capacity is required for each frame, and it becomes uneconomical to utilize the memory capacity. Therefore, an object of the present invention is to provide an image data recording apparatus capable of confirming the image quality of the recorded image data when recording the image data in a memory with a variable compression rate. In order to solve the above-mentioned problems, an image recording apparatus according to the present invention comprises a signal compression means for compressing a supplied video signal at a set compression rate, and the above-mentioned signal. Setting means for variably setting the compression ratio in the compression means, memory means for temporarily storing the output signal of the signal compression means, and decompression processing corresponding to the compression processing for the signal read from the memory means. An external operation of signal decompressing means for applying a signal, a means for obtaining a signal for forming a visible image based on the output of the decompressing means, and a signal transfer for recording the signal read from the memory means on a recording medium. And a signal transfer means for performing the above. According to the present invention, the compression rate at the time of compressing and recording the image data can be arbitrarily set, and the image obtained by the expansion processing corresponding to the compression rate can be reproduced and monitored. As a result, it is possible to efficiently record image data while determining whether the set compression ratio is appropriate. Next, the present invention will be described with reference to the drawings. FIG. 1 shows an embodiment of an image data recording apparatus according to the present invention, and is a configuration block diagram of an application example to an electronic still camera. The image of the subject is C through the lens 1.
An image is formed on a CD (imaging device) 2 and converted into an image signal. The imaging process unit 3 performs predetermined processing such as γ correction on this image signal. The image signal output from the imaging process unit 3 is converted into a digital signal by the A / D converter 4 and then recorded in the frame memory 5 as image data. Image data of each unit block obtained by dividing one screen into blocks of a predetermined unit is read from the frame memory 5, and orthogonal transformation / inverse orthogonal transformation (FDCT / IDC) is performed.
After being subjected to orthogonal transformation (DCT in this case) in the T) section 6, the data compression / decompression section 7 performs final data compression processing. The system controller 15 is composed of a microcomputer and controls the entire electronic still camera. It includes a shutter release button, a TELE switch, and a WIDE.
Upon receiving various instruction signals from the switch group 21 such as switches and the compression parameter change instruction signal from the compression parameter change switch 16, etc., the control signal is sent to each unit. For example, during the focusing operation, the lens driving unit 11 is controlled to move the lens 1 to the optimum position on the optical axis. SSG part 12
Sends and receives signals to and from the system controller 15,
A predetermined signal is output to the CCD 2, the imaging process unit 3, the A / D conversion unit 4, the frame memory 5, and the like. The switch 18 is the system controller 1
The memory 8 is switched and connected to the data compressing / expanding section 7 and the connector 9 in response to the switching signal from 5. The connector 9 is
The memory card 10 is mounted and the memory card 10 is connected to the internal circuit of the camera. The switch 19 switches and connects the data compression / decompression unit 7 to the connector 9 in response to a switching signal from the system controller 15. The compression parameter unit 14 sends a compression parameter determined based on a signal output from the system controller 15 in response to a compression parameter change instruction signal from the compression parameter change switch 16 to the data compression / decompression unit 7 to perform a predetermined compression. It sets the rate. When photographing a subject and obtaining compressed data, the switch 18 is in a solid line connection state, and image data compressed at the compression rate currently defined by the compression parameter section 14 is recorded in the memory 8. To be done. Further, the compressed data read from the memory 8 is supplied to the data compression / decompression unit 7 via the switch 18 and subjected to decompression processing in a decompression mode corresponding to the compression ratio, and the FDCT / IDCT unit 6
Inverse orthogonal transformation is performed and recorded in the frame memory 5. The decompressed data read from the frame memory 5 is MIX
The unit 20 mixes some information (for example, character information) indicating that the current companding result is being generated, which is generated from the system controller 15, and then converted into an analog signal by the D / A converter 13. The analog video signal thus obtained is output as a video signal to the EVF / display unit 17 controlled by the system controller 15 or an external monitor display unit. By reproducing the recorded image on the display unit, the image quality of the image data compressed by the current compression rate can be confirmed. As a result of this confirmation, if the quality of the reproduced image is satisfactory,
The switch 18 is set to the broken line connection state, and the compressed image data recorded in the memory 8 is recorded in the memory card 10 via the connector 9. When the image data recorded in the memory card 10 is reproduced, the switch 19 is set to the connection state, and the compressed image data read from the memory card 10 via the connector 9 is compressed / compressed via the switch 19.
The data is sent to the decompression unit 7, the FDCT / IDCT unit 6 operates, and the decompression process corresponding to the compression is performed and recorded in the frame memory 5. The video data read from the frame memory 5 is transferred to the D / A converter 13 via the MIX unit 20.
To be converted into an analog signal and sent as an image signal E
The image is reproduced by sending it to the VF / display unit 17 or the external monitor display unit. At this time, the MIX unit 20 is not supplied with the character information from the system controller 15, and the normal reproduction screen is displayed. The flowchart of FIG. 2 shows the image recording operation processing procedure in the embodiment of FIG. When the power of the electronic still camera is turned on (step S
1) First, the compression parameter is set to a default value (step S2). Next, the shutter release 1 is "O".
If it is "N" (step S3), and if it is "ON", the image data read from the memory 8 of FIG. 1 is expanded and processed through the frame memory 5-MIX unit 20-D / A converter 13. As a video signal, it is sent out and displayed on the display unit, that is, an image when compressed / decompressed with the currently set compression parameter is displayed (step S4).
The operator views the displayed image and determines whether or not the image quality of the image is satisfactory, that is, whether or not to change the compression parameter (step S5). If the image quality is not satisfactory, the compression parameter is changed (step S6), and the process returns to step S3. Step S5
When the image quality is satisfactory and there is no need to change the compression parameter, the shutter release 2 is turned on.
Then (step S7), the image data is recorded in the memory card (step S8), and the process returns to step S3. FIG. 3 is a schematic view of the electronic still camera in the embodiment shown in FIG. The electronic still camera body 100 is provided with a lens 101, a shutter button 102, a TELE switch 103 and a WIDE switch 104, and the switches 103 and 104 also serve as switches for changing the compression rate. That is, in step S5 of FIG. 2, when the shutter release 1 is ON and the image quality is not satisfactory and the compression rate is desired to be lowered, the WIDE switch 104 is pressed, and when the compression rate is desired to be increased, the TELE switch 103 is pressed to increase the compression rate. Set appropriately. It goes without saying that the compression rate variable setting can be performed by any other switch means. Although the above embodiments describe the application examples of the electronic still camera, the present invention can be applied to an image recording apparatus that performs arbitrary compression / decompression processing other than the electronic still camera. As described above, in the image recording apparatus according to the present invention, the compression rate when compressing and recording the image data can be arbitrarily set, and the decompression processing corresponding to the compression rate can be set. Since the image obtained by can be immediately reproduced, it is possible to efficiently record the image data while determining the suitability of the set compression ratio, and particularly when applied to an electronic still camera, the optimum image quality can be obtained. The compression rate can be set arbitrarily.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of an image recording apparatus according to the present invention,
It is a block diagram of a configuration of an application example to an electronic still camera. FIG. 2 is a flowchart showing an image recording operation processing procedure in the embodiment of FIG. FIG. 3 is a schematic view of the electronic still camera in the embodiment of FIG. [Explanation of reference numerals] 1 lens 2 CCD 3 imaging process unit 4 A / D
Converter 5 Frame memory 6 FDC
T / IDCT section 7 Digital compression / expansion section 8 Memory 9 Connector 10 Memory card 11 Lens drive section 12 SSG
Unit 13 D / A converter 14 Compression parameter setting unit 15 System controller 16 Compression parameter change switch 17 EVF / Display unit 18, 19
Switch 20 MIX section 21 Switch group 100 Electronic still camera body 101 Lens 102 Shutter button 103 TEL
E switch 104 WIDE switch

Claims (1)

Claims: A signal compression means for compressing a supplied video signal at a set compression rate; a setting means for variably setting the compression rate in the signal compression means; and an output signal of the signal compression means. For temporarily storing the signal, a signal decompressing unit for decompressing the signal read from the memory unit, the decompressing process corresponding to the compression process, and a visible image based on the output of the decompressing unit. An image recording apparatus comprising: a means for obtaining a signal; and a signal transfer means for transferring the signal read from the memory means to a recording medium in accordance with an external operation. ..