JP2002290794A - Electronic camera device and image processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera capable of generating a thumb nail image corresponding to a digital zoom image in a short time. SOLUTION: An electronic camera having a digital zoom function and a generation function of the thumb mail image is configured to generate the thumb nail image 42 in response to the digital zoom image using thumb nail image 41 generated from the picked up original image. The thumb nail image 42 is developed by an enlargement processing of extracted image 410 having a predetermined size from the center portion of the thumb nail image 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera apparatus and an image processing apparatus having a digital zoom function.

[0002]

2. Description of the Related Art In recent years, electronic cameras (digital cameras) that convert a subject into image data by an electronic image pickup function and record the image data on a recording medium have become widespread. Electronic cameras use the digital processing function of captured images,
An electronic magnification function (hereinafter, referred to as a digital zoom function) for electronically enlarging an image, referred to as a digital zoom or an electronic zoom, is provided. With this digital zoom function, a pseudo zoom image that does not depend on the optical zoom function can be generated.

In principle, the digital zoom function is, as shown in FIG. 4, an original image (data size is M × N dots) taken by a photographing system (including an optical lens system and an image pickup device such as a CCD). This is a function for generating an image 400 (data size is assumed to be m × n dots) 400 extracted from the central region of the image 40, for example, by enlarging it to an image 50 of the same size as the original image. Thus, a digital zoom image 50 independent of the optical zoom magnification can be output.

[0004] In general, in an electronic camera, when a photographed image is recorded on a memory card and the original image is searched, a thumbnail (thumbnails) that can be easily viewed is used.
l) A function for generating a sample image called an image is provided. The thumbnail image is a sample image corresponding to the photographed main image, and is a reduced image having a small data size. In the electronic camera, a thumbnail image is recorded on the memory card together with the main image. With such a function, by displaying the thumbnail image on the monitor screen of the electronic camera, the photographed image recorded on the memory card can be easily searched. Further, even when a captured image is stored in a personal computer (PC) or the like, the stored captured image can be easily searched for by displaying the thumbnail image on the screen of the PC.

[0005]

Even when a digital zoom image by the digital zoom function is recorded on a memory card or the like, a thumbnail image corresponding to the digital zoom image is generated and recorded on the memory card or the like. In this case, as shown in FIG. 4, a digital zoom image 50 is created from the original image 40, the digital zoom image 50 is further reduced, and a thumbnail image (data size a ×
b dot) 51 is generated. In such a thumbnail image generation method, a digital zoom image 50 of particularly high quality is used.
, A relatively long image processing time is required.

Accordingly, an object of the present invention is to provide an electronic camera capable of generating a thumbnail image corresponding to a digital zoom image in a short time.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an electronic camera having a digital zoom function and a thumbnail image generation function, and uses a thumbnail image generated from a captured original image to generate a thumbnail image corresponding to the digital zoom image. This is the configuration to generate.

That is, the electronic camera according to the present invention includes a first image data generating means for generating first reduced image data having a smaller data amount than the image data based on the image data obtained by the imaging operation. In an operation mode in which enlarged image data enlarged by electronic enlargement processing is generated from image data, a second reduced image data corresponding to the enlarged image data is generated based on the first reduced image data. The image processing apparatus includes image data generating means and image output means for outputting data for generating a visible image from the second reduced image data.

[0009] Specifically, the first reduced image data is
It is a thumbnail image generated from a captured original image.
The electronic camera of the present invention uses a thumbnail image generated from an original image to generate a thumbnail image corresponding to the digital zoom image when generating a digital zoom image that is enlarged image data. Therefore, compared to the conventional method in which a thumbnail image is generated from a digital zoom image by image processing, a thumbnail image corresponding to the digital zoom image is relatively quickly processed by using a thumbnail image generated from the original image. Can be generated. This makes it possible to efficiently generate and record a thumbnail image together with the digital zoom image in the digital zoom operation mode.

[0010]

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

(Configuration of Electronic Camera) FIG. 1 is a block diagram showing a main part of an electronic camera according to this embodiment.

The electronic camera according to the embodiment is assumed to be a digital camera having a digital zoom function and a thumbnail generation function.

As shown in FIG. 1, the electronic camera generally records an image captured by a photographing system 1 in a recording system 21 as image data (digital data) obtained by various types of image processing. In addition, the display output system 22 is used for display.

The photographing system 1 includes an optical lens unit (including a zoom lens, a diaphragm, an autofocus lens, and the like).
10, an imaging device (CCD) 11, an imaging circuit 12,
And an A / D converter 13. The imaging device 11 is usually a CCD (charge coupled device) having several million pixels.
And photoelectrically converts a subject image incident through the optical lens unit 10. The imaging circuit 12 mainly includes an AGC
Various signal processing such as (automatic gain adjustment) processing and CDS (correlation double sampling) processing is performed. The A / D converter 13 converts an imaging signal output from the imaging circuit 12 into image data composed of a digital signal.

The image data obtained by the imaging system 1 is processed by an imaging adjustment system and an image processing system 18 in a narrow sense.
The information is recorded by the recording system 21 and displayed on the display output system 22. The imaging adjustment system includes a luminance signal processing unit 17 and an automatic white balance (AWB) function unit. Besides this,
The imaging adjustment system also includes an AE (auto exposure) function unit and an AF (auto focus) function unit. The luminance signal processing unit 17 performs a process for generating digital luminance data (Y data) from image data. The AWB function section is roughly divided into a micro area integrator 14, a WB evaluation section 15, a WB correction section 16
And The minute area integrator 14 divides the image data into predetermined minute areas, and calculates and outputs RGB data for each of the areas. The WB evaluation unit 15 includes a WB evaluation value calculation unit 150 and a WB detection unit 151. WB correction unit 16
Performs a WB correction process based on the WB detection value obtained from the WB evaluation unit 15.

The image processing system 18 in a narrow sense includes a color matrix correction section, a γ correction section, an LPF color separation processing section, a YC conversion section, and the like for the WB-corrected image data. An encoder function for generating digital code data of digital color data (C data) is realized. A video processing unit (including a video driver) 20 converts the Y data and C data output from the image processing system 18 into analog luminance signals (Y signals) and color signals (C signals), and outputs the converted signals to a display output system. 22. The image compression unit 19 receives the Y data and the C data from the image processing system 18, performs image compression processing of, for example, a JPEG system, and outputs the result to the recording system 21.

The display output system 22 includes an LC having a liquid crystal screen.
It has a D (liquid crystal display) monitor and a video output terminal, and displays a captured image (main image) and a thumbnail image related to the embodiment on the LCD screen. The video output terminal is connected to an external monitor such as a television set by NT.
An external output terminal for transmitting a video signal such as an SC signal. The recording system 21 records image data (including thumbnail images) that have been compressed by the image compression unit 19 using, for example, a memory card as a recording medium.

In this embodiment, as a component for generating a thumbnail image, an SDRAM (synchronous D) is used.
RAM) 30, a thumbnail generation unit 31 that generates a thumbnail image (first reduced image) from a captured image, and a thumbnail image (second reduced image) corresponding to a digital zoom image
And a setting unit 33 for setting digital zoom information related to the digital zoom function. SDRAM 30 is AWB
This is a work memory for temporarily storing RGB data output from the minute area integrator 14 of the functional unit.

In this embodiment, various processing circuits such as an image decompression unit and a strobe control unit, which are not directly related to a thumbnail image generation function, and a system controller and an operation input unit (release unit) constituting a control / operation system (A group of operation switches such as buttons and mode dials) is omitted from FIG.

(Thumbnail Image Generation Processing) Hereinafter, the generation processing of a thumbnail image corresponding to a digital zoom image according to the embodiment will be described with reference to the flowcharts of FIGS. 2 and 3 together with FIG.

First, in the electronic camera, image data (referred to as original image data) corresponding to the subject is obtained from the photographing system 1 in accordance with the operation of the control / operation system (including the operation of the release button and the like) (step). S1). Image data is
As described above, the image data is processed by the imaging adjustment system and the image processing system 18, recorded by the recording system 21, and displayed on the display output system 22.

Here, as shown in FIG. 2, the thumbnail generating section 31 reduces the original image data (data size is set to M × N dots) 40 and reduces the reduced image data (data size is set to a × b dots). ), And outputs the reduced image data as a thumbnail image 41 (step S).
2). Actually, the thumbnail generation unit 31 uses the RGB data temporarily stored in the SDRAM 30 from the small area integrator 14 of the AWB function unit to generate a thumbnail image 41.
Generate

When the operation mode of the digital zoom is not set from the setting unit 33, the enlargement processing unit 32 outputs the thumbnail image 4 generated by the thumbnail generation unit 31.
1 is sent to the recording system 21 and the display output system 22 (NO in step S3, S7). That is, the recording system 21 records a thumbnail image (after compression processing) 41 corresponding to the main image together with the main image obtained by compressing the original image data 40 on the memory card. Display output system 2
As a result, a thumbnail image 41 is displayed on the LCD screen at the time of the main image search processing or the like.

On the other hand, when the operation mode of the digital zoom is set from the setting unit 33, the control
A digital zoom image 43 is generated from image data (original image data) 40 obtained from the imaging system 1 by the operation system. Depending on the setting of the operation mode of this digital zoom,
The enlargement processing unit 32 generates a thumbnail image (second reduced image) 42 corresponding to the digital zoom image from the thumbnail image (first reduced image) 41 generated by the thumbnail generating unit 31.

That is, as shown in FIG. 2, the enlargement processing section 32 extracts an image 410 of a predetermined size from the central area of the thumbnail image 41, and enlarges the image to the data size of the thumbnail image (a × b dots). By processing, a thumbnail image 42 is generated (steps S4, S5). in short,
The enlargement processing unit 32 outputs the original image data (M × N dots) 40
A thumbnail image (second reduced image of a × b dots) 4 corresponding to the digital zoom image using a thumbnail image (first reduced image of a × b dots) 41 generated from
2 is sent to the recording system 21 and the display output system 22 (step S6). That is, the recording system 21 records, on the memory card, a thumbnail image 42 corresponding to the main image together with the main image which is a digital zoom image.
In addition, the display output system 22 displays a thumbnail image 42 on the LCD screen at the time of search processing of the main image.

As described above, according to the embodiment, in the digital zoom operation mode, a thumbnail image (first image) generated from the original image data 40 which is a captured image is generated instead of a thumbnail image generated from a conventional digital zoom image. A thumbnail image 42 corresponding to the digital zoom image is generated using the (1 reduced image) 41. Therefore,
As compared with the conventional generation method, the thumbnail image 42 corresponding to the digital zoom image can be generated independently of the digital zoom image generation processing. In short, the image processing necessary for the generation processing of the thumbnail image 42 is only the processing of the enlargement processing 32, so that the processing is performed in a relatively short time. This makes it possible to efficiently generate a thumbnail image corresponding to a digital zoom image, as compared with a conventional generation method.

When generating a thumbnail image of the original image as described above, when performing image processing at the time of generating the thumbnail image according to the operation mode of the digital zoom, a thumbnail image corresponding to the original image is generated. It is more preferable to improve the image quality of the thumbnail image corresponding to the digital zoom by adaptively controlling a parameter different from the case, for example, a parameter relating to edge processing.

Although the above embodiment has been described with reference to the case of an electronic camera device, the present invention is not limited to this device, and is useful for, for example, a film scanner or an image processing device for editing a photographed image. It is.

[0029]

As described above, according to the present invention, in the digital zoom operation mode, a thumbnail image corresponding to a digital zoom image is generated using a thumbnail image corresponding to a captured image instead of the digital zoom image. . Therefore, a thumbnail image corresponding to the digital zoom image can be generated in a short time and efficiently, and can be recorded together with the digital zoom image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of an electronic camera according to an embodiment of the present invention.

FIG. 2 is an exemplary view for explaining a method of generating a thumbnail image corresponding to a digital zoom image according to the embodiment;

FIG. 3 is an exemplary flowchart for explaining a thumbnail image generation method according to the embodiment;

FIG. 4 is a view for explaining a conventional thumbnail image generation method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photographing system 10 ... Optical lens unit 11 ... Image sensor (CCD) 12 ... Imaging circuit 13 ... A / D converter 14 ... Micro area integrator 15 ... WB evaluation part 16 ... WB correction part 17 ... Luminance signal processing part 18 ... Image processing system 19 Image compression unit 20 Video processing unit 21 Recording system 22 Display output system 30 SDRAM 31 Thumbnail generation unit 32 Enlargement processing unit 33 Digital zoom information setting unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/91 J

Claims (9)

[Claims] A first image data generating unit configured to generate first reduced image data having a smaller data amount than the image data based on image data obtained by an imaging operation; A second image data generating unit configured to generate second reduced image data corresponding to the enlarged image data based on the first reduced image data in an operation mode in which enlarged image data enlarged by the enlargement processing is generated; And an image output means for outputting data for generating a visible image from the second reduced image data. 2. The electronic camera device according to claim 1, wherein said first image data generation means is configured to generate a thumbnail image from said image data obtained by an imaging operation. 3. The image processing apparatus according to claim 1, wherein the second image data generating unit is configured to generate, as the second reduced image data, a thumbnail image corresponding to the enlarged image data. An electronic camera device according to claim 1. 4. The image processing apparatus according to claim 1, wherein the first image data generating unit is configured to generate the first reduced image data as image data for obtaining photometric information or information on a subject such as white balance from the image data obtained by the imaging operation. 2. The electronic camera device according to claim 1, wherein the electronic camera device is configured to generate 5. The image processing device according to claim 1, wherein the second image data generating unit is configured to generate second reduced image data corresponding to the enlarged image data based on the first reduced image data. The electronic camera device according to claim 4, wherein 6. The second image data generating unit is configured to generate the second reduced image data as the thumbnail image under image processing conditions different from those of the first image data generating unit. The electronic camera device according to claim 1, wherein: 7. The apparatus according to claim 1, wherein said image output means is configured to output the second reduced image data as visible image generation data together with the enlarged image data. Electronic camera device. 8. A first thumbnail image generating means for generating a first thumbnail image having a smaller data amount than the original image based on the recorded original image, and electronically enlarging using the original image. A second image data generating unit configured to generate a second thumbnail image corresponding to the enlarged image data by using the first thumbnail image in an operation mode for generating enlarged image data enlarged by processing; An image processing apparatus comprising: 9. The image according to claim 8, wherein said second image data generating means is configured to generate a thumbnail image corresponding to a digital zoom image as said second thumbnail image. Processing equipment.