JP2002095009A - Electronic camera and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera and a printer which can reduce color noise without having to install a special color noise reducing means, and to realize cost reduction and miniaturization. SOLUTION: This electronic camera is equipped with an imaging means 12 for obtaining electronic image data through photoelectric conversion of an imaged object, a recoding means 22 for recording the image data obtained by the imaging means in a recording medium, a converting means 50 for converting image data obtained by the imaging means to luminance component data and color component data, and a changing means 40 of the number of picture elements for changing the number of picture elements of the image data, when the image based on the image data is displayed on a display unit, or in order to change an image size, when the image data are recorded. After the number of pixels is changed with the image being contracted regarding the color component data read from the recording medium, the means 40 changes the number of pixels, so as to enlarge the image of the contracted color component data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print of an image taken by an electronic camera.

[0002]

2. Description of the Related Art When an image photographed by an electronic camera is printed out, it is performed by an external printer or a built-in printer.

However, an image photographed by an electronic camera contains color noise of an image sensor. Even if the color noise is at a level that is inconspicuous when displayed on a monitor, it may be noticeable when printing. is there.

Therefore, it is conceivable to provide a dedicated color noise reduction means in order to reduce color noise. But,
It is not preferable to provide a dedicated color noise reduction unit from the viewpoint of cost reduction and miniaturization.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electronic camera and an image forming apparatus which can reduce color noise without providing any special color noise reduction means and can achieve cost reduction and miniaturization. With the goal.

[0006]

According to the present invention, the following means are provided to solve the above-mentioned problems.

An electronic camera according to the present invention has an image pickup means for obtaining electronic image data by photoelectrically converting a formed subject image, and records the image data obtained by the image pickup means on a recording medium. A recording unit for converting image data obtained by the imaging unit into luminance component data and color component data, and a display unit for displaying an image based on the image data on a display device or the image data. A pixel number conversion unit for converting the number of pixels of the image data in order to change an image size at the time of recording, wherein the pixel number conversion unit performs image conversion on the color component data read from the recording medium. After the number of pixels is converted so as to reduce the number of pixels, the number of pixels is converted so that an image of the reduced color component data is enlarged.

A preferred embodiment of the above electronic camera is as follows. (1) An output unit for outputting print image data including the color component data converted by the pixel number conversion unit to an external printer. (2) There is further provided printing means for printing an image based on print image data including the color component data converted by the pixel number conversion means. (3) compression means for compressing and obtaining compressed image data to record the luminance component data and the color component data on the recording medium, and decompressing the compressed image data read from the recording medium. And decompression means for obtaining luminance component data and color component data, and the pixel number conversion means converts the number of pixels to reduce the image of the color component data obtained by the decompression means,
And converting the number of pixels so as to enlarge the image with respect to the reduced color component data. (4) The image processing apparatus further includes low-pass filter processing means for performing low-pass filter processing on the color component data reduced by the pixel number conversion means, and wherein the pixel number conversion means performs low-pass filter processing by the low-pass filter processing means. Converting the number of pixels so as to enlarge the image of the color component data obtained. The embodiments described above may be applied separately, or may be applied in appropriate combinations.

A printer according to the present invention mounts a recording medium on which image data is recorded, and prints an image based on image data read from the recording medium mounted on the mounting means. And a pixel number converting means for converting the number of pixels of the image data in order to print the image by the printing means, wherein the pixel number converting means is read from the recording medium. After converting the number of pixels for the color component data of the image data so that the image is reduced, the number of pixels is converted so that the image is enlarged for the reduced color component data.

A preferred embodiment of the above printer is as follows. (1) Decompression means for decompressing compressed data including luminance component data and color component data read from the recording medium to obtain luminance component data and color component data, wherein the pixel number converting means After converting the number of pixels for the color component data obtained by the decompression means so as to reduce the image, the number of pixels is converted so that the image is expanded for the reduced color component data. (2) The image processing apparatus further includes low-pass filter processing means for performing low-pass filter processing on the color component data reduced by the pixel number conversion means, wherein the pixel number conversion means is low-pass filtered by the low-pass filter processing means. Converting the number of pixels so as to enlarge the image with respect to the color component data. The embodiments described above may be applied separately, or may be applied in appropriate combinations.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an external view of an electronic camera having a printer function to which the present invention is applied. FIG. 1A is a diagram viewed from the front side of the camera (that is, the subject side), and FIG. 1B is a diagram viewed from the back side of the camera.

In the electronic camera shown in FIG. 1, a zoom lens 11 for taking in an optical image of a subject, a release button 61 for taking a picture, and a light source for supplementing the quantity of light when the quantity of light of the subject is insufficient. A strobe 56 and a print cartridge lid 84 for a cartridge that stores paper for printing an image are arranged. In the electronic camera of FIG. 1, the film 85 is configured to be discharged from above the camera body 10.

On the back of the electronic camera, a mode switch 62 for setting various modes such as photographing, reproduction, printing, etc., a subject image taken from the zoom lens 11, and a recorded image are displayed. An image display LCD 30 for reproduction display, a zoom lever 63 for causing a zoom lens to perform zooming, and a cross key 6 that is integrally formed with the zoom lever and used for various selections and the like, for example.
4 are arranged. By pressing the print button 65, the image is printed, and the film 85 on which the image is printed is discharged from above the camera body 10.

FIG. 2 is a schematic block diagram of the above electronic camera.
FIG. 3 is a schematic block diagram of the printer. FIG. 3 has substantially the same configuration as that of FIG. 2 except for the function of the camera. Therefore, the same portions are denoted by the same reference numerals, and a detailed description thereof will be omitted. The optical image from the subject that has passed through the zoom lens 11 in FIG. 1) is converted into an electric signal by an image pickup device 12, for example, a CCD. And
The image signal is converted into an analog image signal by the
The digital signal is converted by the D converter 14. The digital signal is stored in a built-in memory 35 such as a RAM for temporary storage and then compressed by, for example, a JPEG compression process (the compression is described as JPEG compression in the following description), and the memory I / O is processed. Through F22,
The data is recorded on a removable memory card 20 inserted in the card slot 21.

The external interface 26 is for exchanging data between the electronic camera and an external device. The external interface 26 includes a communication interface such as RS232C, a serial interface, and the like. And other external devices.

The image recorded on the memory card 20 is temporarily read out to a built-in memory 35, and is stored in a video memory 33.
The video signal is converted into a video signal by the video output circuit 32 and displayed on the image display LCD 30, or is displayed as a video output on an external display device (not shown) connected to the video output terminal 31. The ROM 36 is composed of, for example, a rewritable nonvolatile memory (a flash memory such as an EEPROM) and stores a basic control program and the like.

The ASIC 40 performs JPEG compression / expansion processing for compressing an image for recording on a memory card and expanding a compressed image read from the memory card.
A resizing process (that is, a pixel number conversion process) for performing resizing according to the number of pixels for display or printing is performed. Note that a CCD driving circuit (not shown) is controlled by the control signal from the ASIC 40 to drive the image pickup device 12,
Further, the imaging circuit 13 is controlled.

System controller (Syscon) 50
Controls each unit according to an input operation from an operation unit 60 (for example, a release button 61, a zoom lever 63, a cross key 64, or the like in FIG. 1). A power supply unit 70 is connected to the system controller 50, and a battery 71
Is always on by the power from the The electronic camera is also operable with an external power supply, and operates by receiving supply of external power from an external power input terminal 72. At this time, for example, if the battery 71 is a rechargeable battery, the power supply 7
0 indicates that the battery 71 can be charged together with the operation of the camera by the external power supply. Further, a detection signal indicating whether or not the memory card 20 is attached is also input to the system controller 50, and it is also determined whether or not the memory card 20 is attached. Further, the system controller 50 also controls auto power off.

The system controller 50 performs various types of image processing, for example, a YUV system to RG
Conversion processing to B system, USM processing and LPF described later in detail
Processing, and further, color conversion processing for converting to RGB for a printer, and the like are performed.

The system controller 50 is provided with a strobe light emitting section 5.
6 (corresponding to the strobe 56 in FIG. 1) to emit strobe light, and to control the lens drive unit 58 to control the lens drive unit 58 to control the zoom lens system 11. It also has functions.

Further, the system controller 50 includes an LCD shutter 6
7 to change the amount of light from the LED 66,
By controlling the film drive control circuit 82, the film drive circuit 81 is driven to take out the film 85 from the film cartridge 80 and expose it while transporting it. Here, the image data for exposure to the film using the LCD shutter 67 is desired by the LCD control circuit 46 controlling the LCD shutter based on the image data fetched line by line by the line memory 45. The image is exposed to the film 85 as the image. The F battery 83 attached to the film cartridge 80
Is provided in a general instant camera, and does not particularly relate to the features of the present invention.

FIG. 3 is a block diagram of the printer. In FIG. 3, the same parts as those in FIG. 2 are denoted by the same reference numerals. However, since the imaging system is basically removed from the block diagram in FIG. 2, detailed description will be omitted.

FIG. 4 shows the internal memory 3 applied to the present invention.
5 is a diagram illustrating an example of a memory map of No. 5; FIG. The “card data area” is an area for temporarily storing card data. The “work area” is an area used as a work area for performing various processes. "Display data area"
Is an area for temporarily storing image data for display. The “print data” area is an area for temporarily storing image data for display for printing. in this way,
The built-in memory 35 is mapped and used.

FIG. 5 schematically shows an operation flow of the electronic camera configured as described above. This flow simply shows a typical flow of photographing and printing.

First, when the power is turned on by operating the mode switch 62 from the power-off state, a card check is performed. Here, when it is confirmed that the card is mounted, the mode is shifted to each mode. Become.

In the photographing mode, photographing is performed by operating the release button 61. First, AE / AF is performed in the first release operation (half-pressed state), and photographing is performed in the second release operation (fully pressed state). Do. The zoom operation is performed by tilting the zoom lever 63 in either the W or T direction as shown. The operation for achieving the zoom as shown in the figure may be achieved by tilting the lever in the direction of T. The flow of this shooting mode will be described with reference to FIG. FIG. 6 is a flowchart showing the basic flow of photographing.

First, it is determined whether or not the zoom lever has been operated (step A1). If the zoom lever has been operated, the lens is driven according to the operation of the zoom lever (step A2), and the next operation is performed. Wait for. When the first release operation is performed without operating the zoom lever (step A3), AE (auto exposure) and AF (auto focus) operations are performed (step A).
4) If the second release operation is performed (step A5), an imaging process is performed (step A5).
6). Then, the pixel number mode is determined (step A).
7) For example, in the case of the 640 × 480 mode, a pixel number conversion process for converting the number of pixels from 1280 × 960 pixels to an image of 640 × 480 pixels is performed (step A8).
In this case, the number of pixels of the image obtained by the image sensor is 1280 × 960 pixels. Therefore, if the pixel number mode is 1280 × 960, the pixel number changing process is unnecessary, and the process proceeds to the next process. At this point, since the number of pixels is the number of pixels corresponding to the pixel number mode, the image is subjected to WB (white balance) and other image processing (step A9), and data is processed by, for example, data processing by JEPG compression. Compress (Step A
10) Recording image data on a recording medium (step A)
11). In this way, the recorded image is recorded.

For printing in the print mode, 1
There are frame print and index print, and the default value is one frame print. In this case, a desired image is selected by the cross key and printed. The index print mode is set to the index print mode by tilting the zoom lever in the W direction, for example. Then, similarly to the one-frame printing, a desired index is selected and printing is performed.
The flow of the print mode will be described with reference to FIG.
FIG. 7 is a flowchart showing the basic flow of printing.

First, when an image file is read from the memory card 20 (step B1), image processing for display (1) is performed.
(For a frame) (step B2), and the image display LC
An image is displayed on D30 (step B3). At this point, the camera is basically in the single-frame print mode. Here, by operating the cross key 64 to select another image (step B4), the selected image file is read from the memory card 20 (step B4).
1) The operation up to step B4 is repeated. Next, it is detected whether or not the zoom lever 63 has been operated (step B5). If the zoom lever 63 has been operated (in this case, it is assumed that the lever has been operated in the WIDE direction), the index is set. In the mode, the thumbnail data composed of, for example, four frames as shown in FIG. 8 is read from the memory card 20 (step B6). Then, image processing for index display is performed on the read thumbnail data (step B7), and index display is performed on the image display LCD 30 (step B8). Then, during this display, the operation of the zoom lever 63 (step B9) and the operation of the cross key 64 (step B9)
10) and operation of the print button 65 (step B1)
It is determined whether or not 1) has been performed. If the zoom lever 63 is operated (in this case, the lever is operated in the TELE direction) (step B9), the mode shifts to the one-frame print mode (step B2), and the one-frame print Similar to the mode, the user can select another thumbnail image by operating the cross key. When another thumbnail image is selected by operating the cross key (step B10), the thumbnail image corresponding to the thumbnail image selected from the memory card 20 is selected. The thumbnail data is read out (Step B6), and Step B10
The operation up to is repeated. The operation from step B9 is repeated until the print button 65 is operated (step B11), and image processing for printing is performed by operating the print button 65 (step B11), and printing is executed. (Step B
14). In step B5, the zoom lever 6
If no operation 3 is performed, the operation from step B4 is repeated until the print button 65 is operated (step B12), and image processing for printing is performed by operating the print button 65 (step B12) (step B12). B13), print is executed (step B14).
Printing is performed in this manner.

FIG. 9 is a flowchart showing the flow of image processing for display. FIG. 9A is a flowchart for one-frame display, and FIG. 9B is a flowchart for index display. .

In the image processing in the case of one-frame display in FIG. 9A, first, a JPEG-compressed image is read, decompressed, and stored in the work area (step C).
1). In this case, image expansion is performed, for example, every eight lines. Next, the size of the image is determined (step C).
2) If the image size is larger than the display image size (for example, 1280 × 960 pixels), resizing processing (1280 × 960 pixels → 640 × 480 pixels) is performed and stored in the display data area ( Step C3).
If the image size is equal to the display image size in step C2, the image data is copied from the work area to the data display area (step C4). Then, when the operations from Step C1 to Step C4 are completed for all the lines (Step C5), all the image data are completed, and the process is completed.

In the image processing for the index display, the JPEG-compressed image is expanded for all lines and stored in the display data area (step D1). Then, this operation is completed for four frames (step D2).
By doing so, all the image data for display is prepared, and the process is terminated.

Based on the above basic operation, FIG.
A first embodiment of the present invention will be described with reference to FIG. FIG.
5 is a flowchart showing the flow of the first embodiment of the present invention. First, it is determined whether the image display is a one-frame display or an index display (step E1). Here, in the case of one-frame display, the present invention is applied, so that the following steps E2 to E4, which will be described in detail later, are executed. In the case of index display, the present invention is not applied. Execute. In the following description, the displayed image data is a Y component,
The description will be made assuming that the U component and the V component are included. In step E1, if it is a one-frame display, USM is applied to the Y component and stored in the print data area (step E1).
2). Here, the USM process is a process for sharpening an image. For example, as shown in FIG. 11, for example, the own pixel is set to “3”, and the lower pixel and the right pixel are set to “−”. This is a process of calculating the luminance of each pixel by performing weighting as “1”. The algorithm in this case is: For example, Yi _{″, j ″} = Yi _{′, j ′} * 3-Yi _{′ + 1, j′−}
Yi _{′, j ′ + 1} . Next, pixel number conversion processing is performed on the U and V components (for example, 640 × 480 → 160 ×
The process of reducing the number of pixels is applied to the image data 120 and stored in the work area (step E3). In this case, for example, the data in the work area is as shown in FIG. 12B before the pixel number conversion processing when a part of FIG. 12A is extracted, but FIG. The number of pixels is reduced according to the conversion formula shown in FIG. This conversion formula is a conversion formula when the number of pixels is reduced to 1/4. Then, for the U and V components whose number of pixels has been reduced by the pixel number conversion processing, the pixel number conversion processing is performed again to increase the number of pixels (160 ×
120 → 640 × 480), and stores it in the print data area (step E4). As described above, the spike noise can be suppressed by temporarily reducing the number of pixels and increasing the number of pixels again for the U component and the V component. As a result, the color noise of the image sensor is reduced by a special color noise reduction. It can be reduced without using any means.

FIG. 13 is a flowchart showing the flow of the second embodiment of the present invention. In FIG. 13, FIG.
The same processes as those described in FIG. FIG.
Steps up to step E3 of FIG. 3 are the same as those in FIG. After the pixel number conversion processing in step E3, the LPF is applied to the U component and the V component stored in the work area (step F1). This LPF processing is performed, for example, in FIG.
4 is performed by performing the operation shown in FIG. With this LPF processing, pixels having extremely different hues such as spike noise can be reduced. Then, after that, the pixel number conversion processing (step E)
Since the number of pixels is returned to the original number according to 4), the effect of the present invention can be further obtained. Note that the processing after step E4 is the same as that in FIG. 10, and a detailed description thereof will be omitted.

As described above, according to the present invention, the pixel number conversion processing is performed twice (the number of pixels is reduced → the number of pixels is increased twice), so that the noise of the image pickup device needs a dedicated color reduction means. Can be reduced. Further, by performing the LPF after the first pixel number conversion process, color noise can be more effectively reduced.

FIG. 15 is a schematic block diagram of the processing according to the present invention. FIG. 15A is a conventional processing block diagram. (B) of FIG. 15 and (c) of FIG.
Are processing blocks corresponding to FIGS. 10 and 13 of the present invention, respectively, and show processing from JPEG decompression to matrix conversion. In FIG. 15A, a JPEG file is JPEG-decompressed and each component of YUV is output. And LP of two components of UV
The F process is performed, the U'V 'component and the Y component after the process are subjected to matrix conversion, converted to RGB components, subjected to image processing for a printer, and output to the printer. In this case, since the LPF has to process all of the JPEG-decompressed UV components, it becomes very large, and there is a problem in terms of cost and processing. On the other hand, in the present invention, first, in FIG. 15B, the color noise is reduced by simply performing only the pixel number conversion process twice for the two UV components (first embodiment). Corresponding to the form). This way, without the need for a new configuration,
Color noise can be reduced. Further, in FIG. 15C, since the LPF processing is performed after the number of pixels is once reduced by the pixel number conversion processing, the LPF processing is performed for all JPEG-decompressed UV components as in the related art.
Since it is not necessary to perform the processing, the scale can be reduced even when the LPF processing is performed (corresponding to the second embodiment).

The present invention is not limited to the above embodiment of the present invention. In the above embodiment, an electronic camera with a built-in printer has been described, but the present invention may be applied to an electronic camera without a built-in printer. In this case, the print image processing shown in FIGS. 10 and 13 is performed to obtain print image data in the same manner as in the above-described embodiment, and the print image data is output to the external Output to It goes without saying that various modifications can be made without departing from the scope of the present invention.

[0038]

According to the present invention, the following effects can be obtained. The pixel number conversion unit converts the number of pixels to reduce the image only for the color component data first, and then converts the number of pixels to expand the image. Reduced. That is, in the present invention, since the pixel number conversion means that the electronic camera normally has for display on the display device or change of the image size is also used for reducing the color noise of the print image,
Since no separate means for reducing color noise is required, cost reduction and size reduction can be achieved.

Since the image data processed as described above is output to an external printer or a built-in printer,
Good printing with reduced color noise is possible with an external printer or a built-in printer.

By applying a compression (encoding) method using luminance component data and color component data converted from image data, the decompressed color component data can be directly used for color noise reduction. Since no color component data generation means for reducing color noise is required, cost reduction and size reduction can be achieved.

By the low-pass filter processing, high-frequency color noise such as spike noise can be reduced more effectively. Further, low-pass filtering is performed on the color component data whose pixel number has been converted so as to reduce the image, so that high-speed processing can be performed and the filter size can be reduced.

Since the pixel number conversion means for changing the image size so as to match the recording paper at the time of printing is also used to reduce the color noise of the print image, no separate means for reducing color noise is required. Cost and size can be reduced.

In the case where image data is converted into luminance component data and color component data and then compressed and recorded on a recording medium, the decompressed color component data is directly used for color noise reduction. Since no separate color component data generating means for reducing color noise is required, low cost and miniaturization can be achieved.

By the low-pass filter processing, high-frequency color noise such as spike noise can be reduced more effectively. Further, low-pass filtering is performed on the color component data whose pixel number has been converted so as to reduce the image, so that high-speed processing can be performed and the filter size can be reduced.

[Brief description of the drawings]

FIG. 1 is an external view of an electronic camera having a printer function to which the present invention is applied.

FIG. 2 is a schematic block diagram of an electronic camera.

FIG. 3 is a schematic block diagram of a printer.

FIG. 4 is a diagram showing an example of a memory map of a built-in memory 35 applied to the present invention.

FIG. 5 is a diagram schematically showing an operation flow of the electronic camera.

FIG. 6 is a flowchart showing the basic flow of photographing.

FIG. 7 is a flowchart illustrating a basic print flow.

FIG. 8 is a diagram showing a display example of a four-frame thumbnail image.

FIG. 9 is a flowchart illustrating a flow of image processing for display.

FIG. 10 is a flowchart showing the flow of the first embodiment of the present invention.

FIG. 11 is a view for explaining USM processing.

FIG. 12 is a diagram for explaining a pixel number conversion process according to the present invention.

FIG. 13 is a flowchart showing the flow of the second embodiment of the present invention.

FIG. 14 is a diagram for explaining LPF processing.

FIG. 15 is a schematic block diagram of a process according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Camera main body 11 ... Zoom lens system 12 ... Image sensor 13 ... Imaging circuit 14 ... A / D converter 20 ... Memory card 21 ... Card slot 25 ... External input / output terminal 26 ... External interface 30 ... Image display LCD 31 ... Video output terminal 32 Video output circuit 33 Video memory 35 Built-in memory 36 ROM 40 ASIC 45 Line memory 46 LCD control circuit 50 Syscon 56 Flash light emitting unit 57 Lens drive control circuit 58 Lens drive unit Reference Signs List 60 operation unit 61 release button 62 mode switch 63 zoom lever 64 cross key 65 print button 66 LED 67 LCD shutter 70 power supply 71 battery 72 external power input terminal 80 film cartridge 81 Film drive circuit 82 ... fill Drive control circuit 83 ... F battery 84 ... print cartridge cover 85 ... Film

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 1/393 H04N 5/225 F 5C053 1/46 9/07 C 5C055 5/225 9/64 R 5C065 5/91 101 : 00 5C066 9/07 9/79 G 5C076 9/64 1/46 Z 5C079 // H04N 101: 00 5/91 J F term (reference) 2H054 AA01 BB11 2H104 AA19 2H106 AA80 AA85 AB04 AB95 BA27 BA29 BA36 5B057 BA02 CA01 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CC01 CD05 CE03 CE05 CE18 DB02 DB06 DB09 5C022 AA13 AB68 AC69 5C053 FA04 FA08 FA27 GA11 GB36 HA06 HA09 KA04 KA12 KA24 KA25 LA02 LA03 5C055 AA06 BA06 EA04 GA01 A03 CC03 DD03 GG49 5C066 AA01 AA05 AA13 BA01 CA05 DA01 DC01 DD07 GA02 GA05 HA03 HA04 HA06 KC02 KE01 KE09 KM02 5C076 AA21 AA22 BB01 CB04 5C079 HB01 HB04 HB11 LA02 LA14 LA26 LA37 NA02 NA09 NA25 PA00 PA03

Claims (8)

[Claims] An imaging unit configured to photoelectrically convert the formed subject image to obtain electronic image data; a recording unit configured to record the image data obtained by the imaging unit on a recording medium; A conversion unit for converting the image data obtained by the imaging unit into luminance component data and color component data; and changing an image size when displaying an image based on the image data on a display device or recording the image data. And a pixel number conversion unit for converting the number of pixels of the image data, wherein the pixel number conversion unit performs pixel conversion on the color component data read from the recording medium so as to reduce an image. An electronic camera, wherein after converting the number, the number of pixels is converted so as to enlarge the image of the reduced color component data. 2. The electronic camera according to claim 1, further comprising an output unit for outputting print image data including the color component data converted by the pixel number conversion unit to an external printer. Electronic camera. 3. The electronic camera according to claim 1, further comprising printing means for printing an image based on print image data including color component data converted by said pixel number conversion means. Electronic camera. 4. The electronic camera according to claim 1, wherein the compressed image data is compressed to record the luminance component data and the color component data on the recording medium. Compression means for obtaining the image data; and expansion means for expanding the compressed image data read from the recording medium to obtain luminance component data and color component data. An electronic camera, comprising: converting the number of pixels so as to reduce an image of the color component data obtained by the above, and then converting the number of pixels so as to expand the image of the reduced color component data. 5. The electronic camera according to claim 1, wherein a low-pass filter process is performed on the color component data reduced by the pixel number conversion unit. An electronic camera, further comprising: means for converting the number of pixels, wherein the number-of-pixels converting means converts the number of pixels so as to enlarge an image of the color component data which has been low-pass filtered by the low-pass filtering means. 6. A mounting unit for mounting a recording medium on which image data is recorded, and a printing unit for printing an image based on image data read from the recording medium mounted on the mounting unit. A number-of-pixels conversion means for converting the number of pixels of the image data so that the image is printed by the printing means, wherein the number-of-pixels conversion means comprises a color component of the image data read from the recording medium. A printer characterized in that after converting the number of pixels to reduce the image of data, the number of pixels is converted to expand the image of the reduced color component data. 7. The printer according to claim 6, wherein the expansion means for expanding the compressed data including the luminance component data and the color component data read from the recording medium to obtain the luminance component data and the color component data. Furthermore, the pixel number conversion means converts the number of pixels to reduce the image of the color component data obtained by the decompression means, and then increases the number of pixels to expand the image with respect to the reduced color component data. A printer characterized by converting. 8. The printer according to claim 6, further comprising low-pass filter processing means for performing low-pass filter processing on the color component data reduced by said pixel number conversion means. A printer, wherein the number conversion means converts the number of pixels so as to enlarge an image of the color component data which has been low-pass filtered by the low-pass filter processing means.