JPH11177923A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the electronic camera that records image data much more without deleting the existing image data by reducing a data capacity of a selected image even when a residual recordable capacity of a recording medium gets smaller. SOLUTION: The camera has photographing means 1-3, a signal processing section 7 that reduces the storage capacity of photographed image signals, and a recording section 12 that records the image signals whose capacity is revised onto a recording medium. In this case, the image signals whose recording capacity is revised are extracted and the storage capacity of the signals are furthermore reduced by the signal processing section 7 and the reduced signals are recorded again on the recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electronic camera, and more particularly, to an electronic camera.
The present invention relates to an electronic camera that controls a generated code amount when digital data of a video signal representing a still image is compressed.

[0002]

2. Description of the Related Art In a conventional electronic camera, especially a digital camera, a memory card is detachably connected to a camera body having an image pickup optical system and a solid-state image pickup device, and image information representing a still image picked up by the image pickup device is stored in this memory. It is recorded on the card in the form of a digital signal. At the time of recording, the photographer can select the compression ratio of the recorded image from a plurality of compression ratios or recording resolutions, and select the data capacity of the recorded image. In the camera body, the still image read from the memory card is reproduced on a television screen or a liquid crystal monitor built in the camera body. Also, image information recorded on the memory card is transferred to a large-capacity storage device such as a hard disk and used as an electronic album,
Image data communication is performed by being connected to the communication device.

[0003]

In the above-mentioned prior art, the amount of code generated in accordance with a captured image increases or decreases. In addition, by using a high-pixel image sensor, the amount of generated codes increases. For this reason, when a recording medium having the same recording capacity is used, if the number of pixels of the image sensor increases, the number of recordable images decreases. Japanese Patent Application Laid-Open No. 4-237281 allows a user to arbitrarily set the compression ratio of image data when recording an image. However, the code amount of an image once recorded cannot be changed. Unless an already recorded image is deleted in one recording medium, a new image cannot be recorded.

[0004] The present invention has been made in view of the above-mentioned problems, and the present invention provides a method of reducing image data by reducing the data capacity of a selected image even when the remaining recordable capacity of a recording medium is reduced. It is an object of the present invention to provide an electronic camera capable of further recording image data without deleting image data.

[0005]

An electronic camera according to the present invention comprises:
Imaging means for imaging the object scene, storage capacity changing means for changing the storage capacity of the image signal imaged by the imaging means by reducing the storage capacity, and recording means for recording the changed changed image signal on a recording medium. In the electronic camera having the configuration, the changed image signal is taken out, the storage capacity is reduced again by the storage capacity changing means, and the changed image signal is re-recorded on the recording medium.

Accordingly, even if the recordable area of the recording medium becomes small, the operator reproduces the already recorded image, selects the image, and changes the recording resolution or the compression coefficient of the selected image, thereby recording the image. It is possible to reduce the image data capacity and increase the free space on the recording medium,
It is possible to enhance the functions of the electronic camera.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of the configuration of an embodiment of the present invention. In the figure, the same parts are denoted by the same reference numerals. In the figure, 1 is an imaging lens, 2 is an aperture, 3 is an imaging element, and is a solid-state imaging device such as a CCD. Device. These are collectively called imaging means. 4 is a sample hold, 5 is an amplifier,
6 is an A / D converter, 7 is a signal processing unit (storage capacity changing means) which converts an image signal into a luminance signal and a color difference signal, and further performs compression processing of these signals, 8 is a D / A converter, 9 Is a liquid crystal display unit, 10 is a timing generator, 11 is a system controller, 12 is a recording unit (recording means) having a recording medium (not shown), 13 is a work buffer, 14 is a photometric element, 15 is a video amplifier, and 16 is an operator. Is an operation unit for designating a scaling factor for an image being reproduced.

Next, the operation in such a configuration will be described. The system controller 11 performs photographing, playback, transfer of various data, and other processes in the electronic camera.
Is controlled by The amount of light of the subject image captured by the imaging lens 1 is controlled by the aperture 2 and is formed on the imaging element 3. The image pickup signal photoelectrically converted by the image pickup device 3 is sampled by a sample hold 4, amplified by an amplifier 5 at an appropriate amplification rate, and then converted into a digital signal by an A / D converter 6. This digital signal is input to the signal processing unit 7 and converted into a luminance signal and a color difference signal.

The signal processing unit 7 performs a two-dimensional discrete cosine transform (DCT) on the converted data in units of 8 × 8 pixel blocks, and quantizes the obtained DCT coefficients. Thus, the compressed image data is
The data is sent to the recording unit 12 and recorded on a recording medium (not shown).

On the other hand, at the time of reproduction, image data is read out from a recording medium (not shown) to a work buffer 13 via a recording unit, and the signal processing unit 7 performs processing reverse to that at the time of recording, and converts a compressed signal into a luminance signal. A color difference signal is generated, developed in the work buffer 13, and converted into a D / A
The signal is converted into an analog signal by the converter 8 and supplied to a monitor built in the main body or to an external monitor via the video amplifier 15. Next, a compression ratio changing sequence will be described with reference to FIG. During the reproducing operation, when the compression ratio change mode is selected by a mode selection key (not shown), the system controller 11 issues a command to the signal processing unit 7 by data communication to indicate that the compression ratio change mode is set. The signal processing unit 7 that has shifted to the compression ratio change mode
Indicates that the mode is the compression ratio change mode on the liquid crystal display unit or an external monitor.

When the operator selects a compression ratio for the selected image from the operation unit 16 (step 1), the system controller 11 transmits the changed compression ratio to the signal processing unit 7. The signal processing unit 7 performs the compression process again on the image expanded on the work buffer 13 based on the received compression ratio (step 2), and temporarily stores the compressed data on the work buffer 13. In the signal processing unit 7,
The compression process is performed until one screen is completed (step 3). When the generation of the compressed data is completed, the compressed data of the selected image recorded on the recording medium (not shown) connected to the recording unit 12 is deleted. (Step 4),
The compressed data stored on the work buffer 13 is recorded in the deleted area (step 5). Next, a frame filling process is performed on the empty memory space generated by the deletion (step 6). As a result of the frame filling processing, the newly generated empty memory space is moved to the last part of the memory space.

When the frame filling process is completed, the signal processing unit 7 searches for an available memory space in the recording medium (step 7), calculates the number of recordable images, and transmits the number of recordable images to the system controller 11 (step 7). Step 8), the system controller 11 displays the recordable number on a display device (not shown).

According to the present invention, the change of the storage capacity from the operation unit is described by way of the example of the change of the compression ratio. However, the present invention is not limited to this.

[0014]

As described above, according to the configuration of the present invention, the code amount of recorded image data can be adjusted at the time of reproduction, so that the number of recordable images can be increased without deleting recorded data. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a processing flow of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Imaging lens 2 Aperture 3 Image sensor 4 Sample hold 5 Amplifier 6 A / D converter 7 Signal processing unit 8 D / A converter 9 Liquid crystal display unit 10 Timing generator 11 System controller 12 Recording unit 13 Work buffer 14 Photometric device 15 Video Amplifier 16 Operation unit

Claims (1)

[Claims] 1. An image pickup means for picking up an image of an object scene, a storage capacity changing means for reducing the storage capacity of an image signal picked up by the image pickup means and changing the storage capacity, and recording the changed changed image signal on a recording medium. An electronic camera, comprising: a recording unit that extracts the changed image signal, reduces the storage capacity again by the storage capacity changing unit, and re-records the data on the recording medium.