JPH10336494A - Digital camera with zoom display function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the digital camera by which a moving image/still image during image pickup or a reproduced image at reproduction is displayed with zoomup. SOLUTION: A zoom frame selection means 31 is used to select a zoom frame designated by the user among several kinds of zoom frames of a prescribed size, a zoom frame display means 32 is used to expand frame data corresponding to a size of the designated zoom frame as an image so that the center of the zoom frame is in matching with a center of a screen of a liquid crystal display device 16 and the image is superimposed on an image expanded in a frame memory at present and the resulting image is displayed on the liquid crystal display, device 16. A zoom frame moving means 33 moves the zoom frame superimposingly displayed on the image in the middle of the screen so as to surround a desired image (noted image) through the button operation of the user. An image magnification display means 34 magnifies the noted image surrounded by the zoom frame to have a size of the screen of the liquid crystal display device 16 by the linear interpolation method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital camera, and more particularly, to a digital camera with a zoom display function which enables zoom-in display of moving images and reproduced images (still images) displayed on a liquid crystal display during image pickup. And

[0002]

2. Description of the Related Art In recent years, digital cameras (electronic still cameras) have been developed and sold and are becoming popular. 2. Description of the Related Art A digital camera is configured to photoelectrically convert imaging light with a light / charge conversion element such as a CCD to obtain image data, record the image data on a recording medium, and output the image data to an external image processing device such as a personal computer (hereinafter, a personal computer). The external image processing apparatus performs print image data creation processing, outputs the created print image data to a printer, and prints / reproduces a captured image on paper.

Many digital cameras are equipped with a liquid crystal display for displaying a moving image being picked up and a reproduced image from image data recorded on a recording medium. 640 × 480 pixels, 320 × 240 at standard resolution
Many are about pixels.

[0004] In addition, a liquid crystal display is usually provided at the center of the back of the digital camera, or in the case of a flat type, due to a demand for securing a screen as large as possible as easy to see on a digital camera of a limited size. , Behind the double door.

[0005]

As described above, many digital cameras have a liquid crystal display and are configured to display a moving image being captured and to display a reproduced image from image data recorded on a recording medium. I have.

At the time of photographing, the photographer gazes at the subject from the gaze opening of the viewfinder and secures the focal point to perform photographing. In this case, it is preferable that the photographing be performed by zooming like a conventional optical camera with a zoom mechanism. . In a conventional optical camera with a zoom mechanism, zooming is performed by changing the focal length of a lens. In this case, a part of the incident light is taken out from the optical path of the lens by a prism to make the subject zoomed up in the viewfinder's field of view and incident on the viewfinder, thereby focusing the camera in the viewfinder's field of view and the camera. It is configured to match the imaging at

[0007] Further, in a digital camera, a zoom-up is possible by changing the focal length in the same manner as in a conventional optical camera (for example, a three-fold zoom in which the focal length is 37 mm to 111 mm in terms of a conventional camera). There is a digital camera with a function, and it is necessary to take out the incident light by a prism in the same manner as the receiving optical camera in order to make the viewfinder and the image formed by the CCD coincide with each other.

However, a conventional camera having a zoom mechanism, whether it is an optical camera or a digital camera, has a problem that it is more expensive than a camera without a zoom mechanism.

Here, if a zoomed-up image can be obtained without using a conventional zoom mechanism in a digital camera, it is expected that the digital camera will contribute to the popularization of the digital camera.

SUMMARY OF THE INVENTION The present invention has been made based on the above problems and requirements, and is directed to a digital camera with a zoom display function capable of zooming up a moving image, a still image, and a reproduced image displayed on a liquid crystal display during imaging. For the purpose of providing.

[0011]

In order to achieve the above object, a digital camera with a zoom display function according to the present invention is a digital camera that photoelectrically converts an image pickup light and then records it as image data on a recording medium. Image display device capable of display, target image specifying means for specifying a desired target image, and enlarged image display means for enlarging the specified target image at a predetermined magnification and displaying the enlarged target image on the image display device And the following.

In an embodiment of the present invention, in the digital camera with a zoom display function, the image-of-interest designating means includes a zoom-frame selecting means for selecting a zoom frame for designating an enlargement range surrounding a desired image of interest; It is preferable to include a zoom frame display unit that is superimposed and displayed on the image display device, and a zoom frame moving unit that moves the zoom frame to surround a desired image of interest.
It is preferable that the enlarged image display means includes a pixel interpolation means for interpolating pixels based on the selected magnification. In this case, it is preferable that the magnification of the image of interest is set to a magnification selected from the powers of two, and the pixel interpolating means is configured to perform pixel interpolation by a linear interpolation method based on the magnification.

[0013]

FIG. 1 is a block diagram showing a configuration example of a digital camera according to the present invention.

Referring to FIG. 1, a digital camera 100 includes an optical system 1 comprising a lens and a diaphragm mechanism and the like, on which a reflected light from an object to be photographed is incident on a CCD 2, and a CCD 2 for converting the imaging light from the optical system 1 into an electric signal. And a signal processing unit 3 that processes signals from the CCD 2 and outputs it to the frame memory 6 as multi-valued (R, G, B) raster data (image data), and the operations of the signal processing unit 7 and the recording medium control unit 8. A control unit 4 for controlling execution of control, image processing, image compression processing, and the like;
An input means 5 for inputting an instruction from a user by operating a switch or the like, converting the digital signal into a digital signal, and providing the digital signal to the control unit 4, frame memories 6, 6 ', and R, G, B raster data on the frame memory 6 for luminance. A signal processing unit 7 that converts the image into a component Y and color difference components U and V and compresses the image to perform a reduction process for creating a thumbnail image; and receives an output of the signal processing unit 7 and converts and compresses the output into Y, U, and V components. A recording medium control unit 8 for controlling the writing of the recorded image data and the reduced image data at a predetermined position on a recording medium 9 and for controlling the reading of the recorded image data, and data between an external device such as a personal computer and a printer. A serial interface 12 used for transmission and reception of the data, a display means 15 such as an LED lamp for displaying a switch status and a function, and a liquid for displaying a photographed image or an imaging target. Display means 16 comprising a crystal display or the like.

The control unit 4 includes a CPU, a RAM and an R
It is composed of an MPU having an OM.

The frame memory 6 is normally used as an image display memory of the liquid crystal display 16 (1024 × 768 pixels), and the image data is developed in a bitmap image. The frame memory 6 'is used as a menu display memory of the liquid crystal display 16. During display on the liquid crystal display 16, the contents of the frame memory 6 and the frame memory 6 'are superimposed and displayed.

FIG. 2 is a block diagram showing an example of the configuration of the zoom display means 30. The operation mode display means 30 includes a zoom frame selection means 31, a zoom frame display means 32, a zoom frame moving means 33, and an image enlargement display means 34. It is composed of

The zoom frame selection means 31 selects one specified by the user from several types of rectangular zoom frames having a predetermined ratio with the liquid crystal display 16. When one type of zoom frame is used, the zoom frame selecting means 31 may not be provided.

As will be described later, it is desirable that the size of the zoom frame be a power of 1/2 of the vertical and horizontal size of the screen in the interpolation processing performed when the image is enlarged. In the present embodiment, the size of the zoom frame is set to four types of 1/2, 1/4, 1/8, and 1/16 of the screen size, and any one of them is selected by the zoom frame selecting means 31. doing.

The zoom frame display means 32 develops data corresponding to the designated size of the zoom frame into the frame memory 6 'so that the center of the zoom frame coincides with the center point of the screen of the liquid crystal display 16, and the current image is displayed. The image is superimposed on the image developed in the frame memory 6 and displayed on the liquid crystal display 16.

Thus, when the user designates a zoom frame, the zoom frame appears on the screen of the liquid crystal display 16 on which the image is displayed so as to overlap the image (FIG. 3C).
In this case, the center of the screen of the liquid crystal display 16 coincides with the center of the zoom frame.
6 is displayed at the center of the screen.

The zoom frame moving means 33 moves (coordinate conversion) the zoom frame, which is superimposed on the image at the center of the screen, so as to surround a desired image portion (hereinafter referred to as an image of interest) by a button operation of the user.

The image enlargement display means 34 enlarges the image of interest surrounded by the zoom frame to the size of the screen.

More specifically, when the target image is surrounded by a 1/16 zoom frame, the image is enlarged 16 times by the pixel interpolation method. It is enlarged by 8 times by the interpolation method. When it is surrounded by a 1/4 zoom frame, it is enlarged by 4 times by the pixel interpolation method, and when it is surrounded by a 1/2 zoom frame, it is a pixel interpolation method. , And the image of interest is displayed on the entire screen of the liquid crystal display 16. The pixel interpolation method will be described later.

The digital camera 100 rewrites the frame memory 6 more than ten times a second during imaging, and the moving image is displayed on the liquid crystal display 16. It is desirable that the current image be made a still image and then the target image be enlarged without being updated (if not a still image, it is necessary to perform an enlargement operation every time the frame memory 6 is updated, The enlargement operation time must be performed within the update time of the frame memory 6 (for example, if the maximum magnification is 16 times, and if the update time of the frame memory 6 is 1/15 (second), the enlargement is 16 times at the maximum. (It is necessary to repeat the double enlargement operation four times).

FIG. 3 is an explanatory diagram of the zoom display by the zoom frame display means 30.

In FIG. 3A, image data of the mountains 67, 68 and the house 69 are developed in the frame memory 6 and images of the mountains 67, 68 and the house 69 are displayed on the liquid crystal display 16.

When the user selects a 枠 zoom frame on the screen by the zoom frame selection means 31, a zoom frame 62 having a の size of the screen is displayed in the frame memory 6 'as shown in FIG. 3B. Be expanded.

Next, an image and a zoom frame 62 are displayed on the liquid crystal display 16 by superimposing the frame memory 6 and the frame memory 6 'on the display means 32 as shown in FIG.

When the user designates the house 69 as the image of interest, the zoom frame moving means 33 moves the zoom frame 62 so as to surround the house 69 as shown in FIG.
I do.

When the user confirms the image of interest (the house 69) surrounded by the zoom frame 62, the image enlargement display means 34 converts the coordinates of the image within the zoom frame 62 and then interpolates the image in the frame memory 6 with pixel interpolation. The image is displayed on the liquid crystal display 16 after being magnified four times by the method. In this case, the zoom frame may be deleted on the frame memory 6 ', or may be displayed so as to be superimposed on the enlarged image.

If the image of interest is too small to be enlarged even if it is enlarged, the zoom frame selecting means 31 to 31 are again used.
What is necessary is just to repeat the zoom-up by the image enlargement display means 34.

In this embodiment, the zoom display means 30 is constructed so that the image of interest is surrounded by a zoom frame and the image within the range is enlarged to the size of the screen. An image of interest is specified by a cursor-shaped moving point of a size, an image near the cursor is enlarged at a fixed magnification around the cursor position, and the enlarged image is displayed with the cursor position at the center of the screen. You can also do so. If the target image is shifted or the size after the enlargement is not sufficient, the designation of the target image by the cursor is repeated until the target image has a desired size.

In this case, the zoom display means 30 can be configured to enlarge the image near the cursor at a desired magnification centering on the position of the cursor. However, when the linear interpolation method described later is used, Magnification 2x, 4x, 8
It is desirable to specify a power of 2 such as double, 16 times, and so on. When configuring the zoom display means 30 so that an arbitrary magnification can be specified, it is desirable to use a high-speed pixel interpolation method described later.

Further, as shown in FIG. 4, the image enlargement display means 34 includes an enlargement method determination means 341 and a moving image enlargement means 34.
2. It is composed of a still image enlargement unit 343, and it is determined whether the image is being captured or the image is being reproduced by the enlargement method determination unit 341. During the image capture, the moving image enlargement unit 342 uses the simple interpolation method to update the frame memory 6 within the update time. The image of interest is enlarged, and the image formed on the CCD when the shutter button is pressed is set as a still image, and the image at the image of interest (enclosed by the zoom frame or centered on the position designated by the cursor) The image (image) is linearly interpolated and enlarged, and when the image is being reproduced, the image data image (the liquid crystal display 16) taken into the frame memory 6 from the recording medium 9 or 10.
May be enlarged by linear interpolation using the still image enlargement unit 343.

In this embodiment, the pixel interpolation method used in the image enlargement display means 34 is a linear interpolation method. However, the present invention is not limited to this. For example, the image can be enlarged by a simple interpolation method. However, instead of changing the focal length of the lens to obtain a zoom image, instead of enlarging the image and obtaining a zoom image,
A linear interpolation method or a high-speed interpolation method (described later) that can maintain a certain level of resolution is used instead of the simple interpolation method, which has a disadvantage that the quality of an enlarged image is rapidly reduced as the image quality is coarse and the enlargement ratio is large. It is desirable.

The zoom display means 30 may be constituted by a program. However, when the resolution is 1024 × 768, which is larger than that of the conventional digital camera, as in the digital camera 100 of this embodiment, the image enlargement display means 34 is used. In order to improve the enlargement speed of the zoom display means 30, the zoom frame selection means 31, the zoom frame display means 32 and the zoom frame moving means 33 of the zoom display means 30 are configured by a program, and the pixel interpolation method of the image enlargement display means 34 is hardened. It is desirable to configure with hardware. In this case, as the pixel interpolation method used in the image enlarged display means 34, it is desirable to use a linear interpolation method in which the image quality can be compared with other methods.

<Pixel Interpolation Method> In the case of enlarging an image, simply increasing the distance between adjacent original pixels makes it impossible to obtain an image having a resolution capable of maintaining image quality. After conversion to a position suitable for the enlargement magnification and rearrangement on the bitmap, new pixels are positioned between the original pixels, and the enlarged bitmap is interpolated with new pixels to obtain enlarged image data.

In this case, there are a typical linear interpolation method and a simple interpolation method as pixel interpolation methods.

1. Linear interpolation method The linear interpolation method is a method of performing resolution conversion by linearly interpolating between two adjacent points A and B as shown in FIG. 5 to maintain a constant level of resolution.

In FIG. 5, two adjacent points are represented by A (0, Ay),
Assuming that B (1, By), a newly inserted point P (Px,
Py) can be expressed as follows.

Py = (By−Ay) × Px + Ay (1) where Py is the gradation of point P for which Py is to be obtained, Ay is the gradation of known point A (8-bit positive integer), and By is the known point B. (A positive integer of 8 bits), and Px is the distance of point P from point A. Also, 0 ≦ Px ≦ 1.

This is expanded two-dimensionally and the known points are represented by A,
Assuming that B, C, and D are used, and R is an insertion point, Py = (By−Ay) × Px + Ay (2) As shown in FIG. 6, Qy = (Dy−Cy) × Px + Cy (3) When a new point R is obtained from the two points P and Q, Ry = (Qy−Py) × Rx + Py (4), so that the equations (2) and (3) are substituted for Py and Qy, and Ay, By, When Cy and Dy are arranged, the point R
Can be expressed by the following equation (5).

Ry = (1-Rx) × (1-Px) × Ay
+ (1-Rx) × Px) × By + Rx × (1-Px) ×
Cy + Rx × Px × Dy (5) Equation (5) is a general equation for two-dimensional linear interpolation.

In the linear interpolation method, the gradation between two points can be obtained, and the resolution of the enlarged image can be kept at a certain level, so that the image quality can be compared with other methods. However, when performing an interpolation operation using a computer, the values of Rx and Px in the calculation formula are 、 １, 1 and 2, respectively.
If the values are / 4, 1/8, ... (powers of 2 such as 2 times, 4 times, 8 times, etc.), the calculation result can be obtained by the shift operation. For other multiples, for example, 5 times, 6 times, 7 times, 9 times, 1
When the magnification becomes 0 times, complicated division is needed,
It takes a long time to process. Therefore, when the zoom display means 30 is configured to select a zoom frame using the zoom frame selection means 31 as in the present embodiment, the size of the zoom frame is set to １ ／, ４, 1 .., 1/16,... Is preferably a reciprocal of a power of 2 (enlargement magnification is a power of 2 such as 2, 4, 8, 16 or 16).

The above linear interpolation method can be configured by a program, or can be configured as a linear interpolation circuit using an adder and a multiplier.

2. Simple interpolation method The simple interpolation method uses the original pixels A, B,
When the positions of C and D are obtained, and the magnifications are R and S (both are positive integers), the original pixel is copied R-1 times in the X direction,
This is a method in which the original pixels are copied S-1 times in the Y direction after the copying in the X direction is completed to fill the intervals.

First, the position of each original pixel is determined, and each original pixel is arranged. Then, for each original pixel, R-1 original pixels are copied and filled in the X direction sequentially from the right side of the original pixel. After the interpolation in the X direction is completed,
S-1 lines are copied in the direction to fill the space between lines. The above-described operation is repeated for the pixels subsequent to the next row to interpolate the matrix of the original pixels at a desired magnification R × S.

FIG. 7 is an explanatory diagram of the simple interpolation method, in which the sub-scanning direction is X, the main scanning direction is Y, and the magnification is R = 4, S = 5.

As shown in FIG. 7A, the origin is defined as an original pixel A, and adjacent original pixels A (0,0) and B (0,
First, when an image composed of C (1,0) and D (1,1) is enlarged four times in the X direction and five times in the Y direction, the positions of the original pixels A, B, C, and D after the enlargement are obtained. Are A (0,0), B (0,
5), C (4,0) and D (4,5) (FIG. 7)
(B)).

Therefore, the original pixels A, B, C, and D are copied only 4-1 = 3 times in the X direction to fill the interval, and when the copying in the X direction is completed, 5-1 = 4 times in the Y direction. Copy a line. By this operation, as shown in FIG.
A double-magnified image is formed on the bitmap.

The simple interpolation method is the fastest in comparison with other interpolation methods. However, since the gradation is not adjusted and only copying is performed, the image quality is coarse and the larger the enlargement ratio, the larger the enlarged image. Since the quality is rapidly reduced, it is desirable to enlarge the image by about four times. However, the present invention can be used when enlarging a moving image that is updated more than ten times a second.

3. High-speed pixel interpolation method In addition to the above-described linear interpolation method and simple interpolation method, a pixel interpolation method combining a linear interpolation method and a simple interpolation method.
No. -276468 can be used.

In the high-speed pixel interpolation method, for an arbitrary interpolation magnification R, a linear interpolation magnification S not exceeding the interpolation magnification R is determined, then linear interpolation is performed with the magnification S, and thereafter, simple interpolation is performed for V = RS. Even when the interpolation magnification is not a power of 2 (for example, 11 times), a clear enlarged image can be obtained at high speed.

[0055]

FIG. 8 is a diagram showing an embodiment (an example of the configuration of the back) of the digital camera 100. A liquid crystal display 16 for displaying an image being picked up or a reproduced image and a menu is provided on the right side of the back. On the left side, a button 17 for designating the zoom magnification of the displayed image is provided, and on the left side, a button 18 for selecting a zoom frame, a button 19 for moving a zoom frame,
20 and 21 are provided.

In FIG. 8, a viewfinder 25 is provided on the upper left side of the rear surface, an LED 26 is provided on the right side of the viewfinder 25, and a power switch 27 for the liquid crystal display 16 is provided on the upper right side of the liquid crystal display 16. .

FIG. 9 is a flowchart showing an operation example of the digital camera 100 during the zoom display operation. Hereinafter, description will be made with reference to FIGS. 3 and 8.

In step S1, when the user presses the button 18, the zoom frame selection means 31 sets the zoom frame counter to 1 and passes control to the zoom frame display means 32. Take the reciprocal of the power and take a zoom frame of that size (1 on the LCD screen)
(A zoom frame having a size of / 2) is displayed so as to be superimposed on the currently displayed image with the center of the screen as the center of the zoom frame (FIGS. 3A and 3B).

In step S2, the user further presses button 18
When is pressed, the zoom frame selection means 31 adds 1 to the zoom frame counter value and counts up, and passes control to the zoom frame display means 32. The zoom frame display means 32 calculates the reciprocal of the power of 2 by the zoom frame counter value. The zoom frame data of that size is image-developed on the frame 6 'so that the center of the zoom frame coincides with the center point of the screen of the liquid crystal display 16, and is superimposed on the currently displayed image and displayed. In other words, when the user keeps pressing the button 18, 1/2, 1
/ 4, 1/8, and 1/16 zoom frames are sequentially displayed.
However, in this embodiment, 1/16 of the screen (counter value ≦ 4)
When the button 18 is kept depressed any longer, the counter value is set to 1 again. When the user releases the button 18 from the button 18, the zoom frame selection unit 31 sets the currently displayed zoom frame to the selected zoom frame 62 (FIG. 3).
(C)).

The zoom frame to be developed by the zoom frame display means 32 is defined in advance as data (for example, a data table) by the zoom frame display means 32 itself, and the zoom frame display means is developed so that the image is developed according to the count value. 32 may be configured, or the zoom frame display means 32 may be configured to calculate the coordinates of the zoom frame image according to the counter value and develop the image.

At step S3, the user presses the buttons 19, 2
When 0 or 21 is pressed, the zoom frame moving means 33 moves the zoom frame 62 displayed on the image in the center of the screen so as to be superimposed on the image at a constant pitch, right and left or up and down. Thus, the user can move the zoom frame 62 so as to surround the image of interest 69 (FIG. 3D).

In step S4, when the user presses the button 17, the image enlargement display means 34 sends the coordinates of the zoom frame 62 (the coordinates (i,
j), (k, j), (k, l), (i, l)), find the coordinates of the frame memory 6 corresponding to the coordinates, and cut out the target image 69 surrounded by the zoom frame 62. Then, coordinate conversion is performed so that the center point is set to the center point (α, α) of the frame memory, and then enlarged by the linear interpolation method.

For example, as shown in FIG. 3, when a zoom frame 62 of の of the screen is selected, an image portion surrounded by the zoom frame 62 is cut out, and the center of the frame memory 6 and the center of the zoom frame 62 are extracted. Are moved (coordinate conversion) so that they match, and pixels are interpolated and enlarged by a linear interpolation method (FIG. 3).
(E)).

The enlarged image data is recorded on the recording medium 9 or the extended recording medium 10 or transmitted to an external device.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and it goes without saying that various modifications can be made.

[0066]

As described above, according to the present invention, it is possible to specify a desired image portion in an image displayed on an image display device such as a liquid crystal display and to perform zoom-up display. When a camera is configured, image data enlarged by zoom-up can be obtained without providing a mechanism for projecting a part of light passing through a lens to a viewfinder. Further, since there is no need to provide a mechanism for projecting a part of the light passing through the lens to the viewfinder, a digital camera with a zoom display function that is less expensive than a conventional digital camera with a zoom display function can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a digital camera according to the present invention.

FIG. 2 is a block diagram illustrating a configuration example of a zoom display unit.

FIG. 3 is an explanatory diagram of zoom display by a zoom frame display unit.

FIG. 4 is a block diagram illustrating a configuration example of an image enlargement unit.

FIG. 5 is an explanatory diagram of a linear interpolation method.

FIG. 6 is an explanatory diagram of a linear interpolation method.

FIG. 7 is an explanatory diagram of a simple interpolation method.

FIG. 8 is a diagram illustrating an embodiment (an example of a rear configuration) of a digital camera.

FIG. 9 is a flowchart illustrating an operation example of the digital camera during a zoom display operation.

[Explanation of symbols]

 Reference Signs List 16 liquid crystal display (image display means) 31 zoom frame selecting means (target image specifying means) 32 zoom frame displaying means (target image specifying means) 33 zoom frame moving means (target image specifying means) 34 image enlargement displaying means 62 zoom frame ( Attention image designating means) 69 Attention image 100 Digital camera

Claims (4)

[Claims] 1. A digital camera that photoelectrically converts imaging light and then records the imaged light on a recording medium as image data.
An image display device capable of displaying a moving image, an attention image designating unit for designating a desired attention image, and an enlarged image for enlarging the designated attention image at a predetermined magnification and displaying the enlarged attention image on the image display device A digital camera with a zoom display function, comprising: a display unit. 2. The digital camera with a zoom display function according to claim 1, wherein the image-of-interest specifying means selects a zoom frame for specifying an enlargement range surrounding a desired image of interest, and a zoom frame. A zoom frame display means for superimposing and displaying an image on the image display device, and a zoom frame moving means for moving the zoom frame to surround a desired image of interest. Digital camera. 3. The digital camera with a zoom display function according to claim 1, wherein the enlarged image display means includes pixel interpolation means for interpolating pixels based on the selected magnification. With digital camera. 4. The digital camera with a zoom display function according to claim 3, wherein the enlargement magnification of the image of interest is a magnification selected from powers of two, and the pixel interpolation means performs a linear interpolation method based on the magnification. A digital camera with a zoom display function, which is means for interpolating pixels according to (1).