JP2001136429A - Electronic camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic camera that displays an image peaking processed and electronically zoomed. SOLUTION: An image processing section 431 applies analog processing to an image signal picked up by a CCD 214. An analog/digital converter 432 converts the image signal after the analog processing into a digital signal. A DSP 433 applies image processing to the image data after the digital conversion. The DSP 433 applies differentiation arithmetic operation to a luminance signal calculated at the image processing and sums a differentiation result to an original luminance signal Y to conduct peaking. Let an electronic zoom magnification be N, then the DSP 433 applies interpolation processing to a luminance signal Y' after peaking by a multiple of N longitudinally and laterally and writes the result to a frame memory 435. A display LCD 420 displays the image data written in the frame memory 435.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic camera which captures an image of a subject with an imaging device such as a CCD and records image data on a recording medium or the like.

[0002]

2. Description of the Related Art Conventionally, an image pickup apparatus that picks up an image of a subject passing through a photographic lens and outputs an image signal, and converts a high-frequency component signal into a low-frequency component signal with respect to an image signal output from the image pickup apparatus 2. Description of the Related Art There is known a video camera including an image signal processing circuit that performs a so-called peaking process, which emphasizes a high contrast portion of an image. For example, in the television camera described in Japanese Patent Publication No. 6-28392, focus adjustment is performed such that the spatial frequency characteristics of vision are corrected to enhance the contrast of an image by a viewfinder, and the edge of the image is sharp.

[0003]

When the peaking processing is applied to an electronic camera, the following problem occurs when the electronic zoom processing and the peaking processing performed in the electronic camera are performed in combination. The inventor has found. When performing a peaking process after performing an electronic zoom process of electronically enlarging an image by interpolating an imaging signal output from an imaging device, a high-frequency component included in the imaging signal by an electronic interpolation process by the electronic zoom process Decrease. For this reason, when peaking processing is performed to emphasize the high-frequency component signal with respect to the low-frequency component signal, there is a problem that the contrast of the image cannot be enhanced sufficiently. In particular, a problem tends to occur when the electronic zoom magnification is high.

It is an object of the present invention to provide an electronic camera capable of sufficiently enhancing an image signal when performing a combination of an enlargement process and a peaking process on the image signal.

[0005]

FIG. 3 shows an embodiment of the present invention.
The present invention will be described with reference to FIG. (1) An electronic camera according to the first aspect of the present invention includes a photographing lens.
An imaging device 214 that captures a subject image through the imaging device 2;
A signal processing unit 433 that performs predetermined processing on the image signal output from 214 to emphasize the image signal, a magnification change unit 433 that changes the magnification of an image based on the image signal independently of the signal processing unit 433, and an image signal. Display means 420 for displaying an image by
With the provision of the above, the above-described object is achieved. (2) An electronic camera according to a second aspect of the present invention is a photographing lens.
An imaging device 214 that captures a subject image through the imaging device 2;
A signal processing unit 433 that performs predetermined processing on the image pickup signal output from the 214 to emphasize the image pickup signal; a magnification change unit 433 that changes the magnification of an image based on the image pickup signal output from the signal processing unit 433; The above-described object is achieved by providing the display unit 420 that displays an image based on the imaging signal output from the unit 433. (3) An electronic camera according to a third aspect of the present invention is a photographing lens.
An imaging device 214 that captures a subject image through the imaging device 2;
Magnification changing means 433 for changing the magnification of the image by the imaging signal output from 214, the imaging signal output from the magnification changing means 433 is thinned out, and the thinned image signal is subjected to a predetermined process to perform the thinned image signal. Signal processing means 433 that emphasizes
The above-described object is achieved by providing a display unit 420 that displays an image based on the imaging signal output from the signal processing unit 433. (4) In the electronic camera according to the third aspect, the thinning of the imaging signal output from the magnification changing unit 433 is performed by a ratio of 1 / (the magnification changed by the magnification changing unit). It is characterized by being performed as follows.

[0006] In the section of the means for solving the above-mentioned problems, which explains the configuration of the present invention, the drawings of the embodiments are used to make the present invention easier to understand. However, the present invention is not limited to this.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS -First Embodiment- An embodiment of the present invention will be described below with reference to the drawings.
FIGS. 1A and 1B show the external appearance of an electronic still camera according to a first embodiment of the present invention when the electronic still camera is stored and when the electronic still camera is carried, wherein FIG. 1A is a view seen from above, and FIG. . 2A and 2B show the appearance of the camera shown in FIG. 1 during normal shooting, where FIG. 2A is a view seen from the front, FIG. 2B is a view seen from the top, and FIG. is there. Electronic still camera 1 according to this embodiment
Is a lens unit 1a including a movable lens 2 and a display LCD 4
Monitor unit 1b including 20 and both units
1a and 1b are relatively rotatably connected.

During storage or carrying, as shown in FIG. 1, the lens unit 1a is rotated so that the lens unit 1a and the monitor unit 1b are flat. In addition, during normal photographing, as shown in FIG. 2, the lens unit 1a is rotated so that the movable lens 2 faces the subject. At this time, the monitor unit 1b is held so that the display LCD 420 faces the direction of the photographer.
You can shoot while watching 420.

The lens unit 1a includes an electronic flash device 4, a finder window 5, a red-eye reduction / self-timer display lamp 6, a finder eyepiece window 7, and the like, in addition to the movable lens 2. On the other hand, the monitor unit 1b includes a main switch 8, a release button 9, and a display panel 1 in addition to the display LCD 420.
0, Flash shooting mode button 11, Shooting distance mode button 1
2, image quality mode button 13, zoom operation button 14, monitor display button 15, menu button 16, selection dial 17,
Peaking area selection buttons 19a to 19d are provided.

The electronic still camera 1 has two operation modes: a recording mode for capturing an image of a subject and recording image data, and a reproduction mode for reading and reproducing the recorded image data. By a switching operation of the main switch 8, a recording mode (REC) and a reproduction mode (PLAY) are selected. The main switch 8 is switched to at least four positions of PLAY, OFF, REC (S), and REC (C). The recording mode is an operation mode in which a captured subject image is recorded as image data, and the reproduction mode is an operation mode in which the recorded image data is read and displayed on the display LCD 420. The recording mode is
It has two modes (S) and (C), (S) is a single-frame shooting mode for shooting one frame at a time, and (C) is a continuous shooting mode (or a moving image mode) for continuous frame shooting. .

FIG. 3 is a block diagram showing a circuit of the electronic still camera 1 according to the first embodiment. When the main switch 8 is switched to the recording mode: REC (S), the power of the electronic still camera 1 is turned on and the CPU 439 is set to the ROM.
The control program stored in 443 is started. The recording / playback switch 467 and the continuous shooting mode switch 468 are operated in conjunction with the main switch 8, and when the main switch 8 is operated to the REC (S) position, the recording / playback is switched. The switch 467 is switched to the recording mode, and the continuous shooting mode changeover switch 468 is switched to the one-frame shooting mode. The CPU 439 appropriately controls the blocks of each unit based on operation signals input from the operation members 46 such as the switches and buttons described above.

In FIG. 3, a subject light L is transmitted to a movable lens 2.
, Is incident on the electronic still camera 1, and the incident subject light L passes through the movable lens 2, the fixed lens 209, and the lens group 21 to form an image on the image sensor 214. The imaging element 214 is a CCD, and photoelectrically converts an optical image formed on each pixel into an electrical image signal. A digital signal processor (hereinafter referred to as DSP) 433 supplies a horizontal drive signal to the CCD 214 and a CCD drive circuit 434.
To supply a vertical drive signal to the CCD 214.

The image processing unit 431 is controlled by the CPU 439, samples the image signal photoelectrically converted by the CCD 214 at a predetermined timing, and amplifies the image signal to a predetermined signal level. Analog / digital conversion circuit (hereinafter A
A / D conversion circuit 432 converts the amplified image signal output from the image processing unit 431 into a digital signal, and outputs the digitally converted image data to the DSP 433 described above. The DSP 433 performs image processing such as contour compensation, gamma correction, and white balance adjustment on the image data output from the A / D conversion circuit 432.

Further, the DSP 433 controls a data bus connected to the buffer memory 436 and the memory card 424, and stores the processed image data in the buffer memory.
After the image data is once stored in the buffer memory 436, the stored image data is read out from the buffer memory 436, and a predetermined format process is performed for, for example, JPEG compression. Then, the data is recorded on the memory card 424. Also, DSP4
A frame memory 43 stores the image data after the image processing described above.
5 and display it on a display LCD 420 provided in the monitor unit 1b (FIG. 2), or read out and expand the captured image data recorded from the memory card 424, and store the expanded captured image data in the frame memory. The information is stored in the display 435 and displayed on the display LCD 420. Further, the DSP 433 performs data input / output timing management for recording the above-described image data on the memory card 424 and recording the decompressed photographed image data on the buffer memory 436.

The buffer memory 436 stores image data from the CCD 214. The difference in the speed of input and output of image data to and from the memory card 424, the CPU 439 and the DSP 433.
It is used to mitigate the difference in processing speed in such as. The timer 445 has a built-in clock circuit and outputs time data corresponding to the current time to the CPU 439. This time data is stored in the memory card 42 together with the image data described above.
Recorded in 4.

FIG. 4 is a perspective view of the lens group 21 described above. Inside the lens group 21, an aperture plate 215 and a shutter plate 2
08 is provided adjacently, and the aperture plate 215 and the shutter plate 208 are sandwiched between the relay lenses 212a and 212b. The aperture plate 215 and the shutter plate 208 are formed in a disk shape, and are driven by step motors 408 and 415 (FIG. 3) provided at the rotation center of the disk, respectively. As shown in FIG. 4, the aperture plate 215 is provided with aperture openings 215a to 215g. Based on the area of the opening 215a through which all the subject light beams pass, the aperture areas of the aperture openings 215b to 215g are:
The opening area is set so that the opening area becomes half in order to reach the openings 215b to 215g. On the other hand, the shutter plate 208 is provided with a complete light blocking portion 208a for blocking all light beams, and an opening 208b for passing all light beams.

Referring to FIG. 3, the aperture driving circuit 453 has an A / A
The stepping motor 415 is driven by using the luminance of the subject detected from the image data output from the D conversion circuit 432 to the DSP 433 to drive the stepping motor 415 so that the aperture value is determined by a predetermined exposure calculation performed by the CPU 439. Set the opening diameter of 215. When the step motor 415 is driven, the aperture plate 215 sets an opening having a predetermined opening diameter on the optical path. The shutter drive circuit 454 drives the step motor 408 to set the opening 208b of the shutter plate 208 on the optical path when exposing the CCD 214, and to set the complete light-shielding section 208a on the optical path when the exposure is completed. The control of the exposure time is performed by an electronic shutter operation described later.

The lens drive circuit 430 drives the movable lens 2 to a focus position according to a command from the CPU 439. The lens drive circuit 430 can drive the movable lens 2 to the in-focus position not only by a command from the CPU 439 but also by an operation signal of the distance ring 462. The zoom lens drive circuit 429 drives the movable lens 2 according to a command from the CPU 439 to change the zoom magnification (focal length) of the movable lens 2 and an electronic zoom magnification described later.

A colorimetric element 417 detects the color temperature of the main object and its surroundings, and converts the data of the detected color temperature into a colorimetric circuit.
Output to 452. The colorimetric circuit 452 performs a predetermined process on the analog signal output from the colorimetric element 417 to convert the analog signal into a digital value, and outputs the converted digital signal to the CPU 439.
The interface 448 is provided so as to connect a predetermined external device (not shown) and transmit and receive data between the CPU 439 and the connected external device.

The switch 471 is turned on / off by a command from the CPU 439 in conjunction with the operation of the monitor display button 15 (FIG. 1), and turns on / off the power supplied to the display LCD 420. When the display LCD 420 performs a display operation, the power supplied from the power supply circuit 480 is turned on, and the display LC
When the display operation is not performed by D420, the power supplied from the power supply circuit 480 is turned off. The power is always supplied from the power supply circuit 480 to the other circuit blocks when the power is turned on by the main switch 8.

In addition, a display circuit 440 is connected to the CPU 439 to set the light emission mode of the flash device 4 by the flash shooting mode button 11, set the distance range by the shooting distance mode button 12, and set the compression ratio by the image quality mode button 13. Various setting states are displayed on the display panel 10.

-Peaking Process- The peaking process is performed by the DSP 433 on image data corresponding to a peaking area, which will be described later, of the image data processed by the DSP 433. CPU439
Is set to the peaking processing mode by the instruction of (1), the luminance signal Y calculated by using the image data at the time of image processing,
The color difference signal RY and the color difference signal BY are stored in a buffer memory 436.
Is read from. The read luminance signal Y is differentiated, and the differentiated luminance signal is added to the original luminance signal Y. The luminance signal Y ′ after the addition is treated as a luminance signal after the peaking process.

The color difference signal RY and the color difference signal BY read out from the buffer memory 436 are the same as those of the color difference signal RY and the color difference signal BY when the luminance signal after the above-described differential operation is larger than a predetermined value. The values are replaced with 0, respectively, to obtain a color difference signal after the peaking process. On the other hand, when the luminance signal after the differential operation is equal to or less than the predetermined value, the buffer memory 43
6, the color difference signal RY and the color difference signal BY read from
Is used as a color difference signal after the peaking process.

The above-described peaking processing is performed on the image data corresponding to the peaking area, and the image data subjected to the peaking processing is written into the frame memory 435, so that the peaking processing is performed on the display LCD 420. The image data is displayed. At this time, in the peaking process, since the color difference signal of the portion where the luminance signal after the differential operation is larger than the predetermined value is replaced with 0, the data of this portion is displayed on the display LCD 420 as white. That is, a portion having a high contrast, such as the outline of the subject image, is displayed with high luminance and emphasized white.

On the other hand, in the peaking process, the color difference signals of the portion where the luminance signal after the differential operation is equal to or less than the predetermined value are the color difference signals RY read from the buffer memory 436, respectively.
And the color difference signal BY is used as it is. That is, the data of the low contrast portion of the subject image is displayed on the display LCD 42 based on the color difference signals RY and BY.
Displayed as 0. When the peaking processing mode is released by a command from the CPU 439, the luminance signal Y, the color difference signal RY, and the color difference signal BY read from the buffer memory 436 are read.
Means frame memory without peaking
The data is written to the display 435 and displayed on the display LCD 420.

As described above, in the electronic still camera 1, the recording mode (REC (S) and REC (C)) and the reproduction mode (PLAY) are switched by the recording / reproduction switch 467 operated in conjunction with the main switch 8. Selected. In both operation modes, a menu setting mode for selecting / setting a camera operation is provided. The electronic still camera 1 according to the first embodiment is characterized by a camera operation set in a menu in the recording mode, and thus the menu setting will be described in the recording mode.

-Recording Operation- When the main switch 8 is switched to a recording mode for single-frame shooting: REC (S), the electronic still camera 1 is switched to a recording mode for single-frame shooting when the power is turned on. In this recording mode, a half-press signal and a full-press signal are input to the CPU 439 from a half-press switch and a full-press switch (hereinafter, referred to as the release button 9) interlocked with the release button 9, respectively. When a half-press signal from the release button 9 is input, the CPU 439 detects the focus adjustment state of the movable lens 2 based on the contrast of the image data by the CCD 214. Then, the movable lens 2 is driven to the in-focus position so that the subject light incident on the movable lens 2 forms an image on the CCD 214 as an imaging device. When a half-press signal from the release button 9 is input to the CPU 439, the CPU 439
Detects the brightness of the subject from the image data obtained by the CCD 214, and performs an exposure calculation based on the detected brightness.

When the zoom operation button 14 is operated, the CP
The zoom lens drive circuit 429 drives the movable lens 2 according to a command from U439 to change the focal length. The focal length of the zoom operation button 14 is moved to one of the telephoto side (T) and the wide-angle side (W).

When the release button 9 is turned on following the half-press signal and a full-press signal is input to the CPU 439, the result of the exposure calculation and the mode setting preset by the flash photography mode button 11 are set according to the result. The flash device 4 emits light, and the subject light L from the movable lens 2 forms an image on the light receiving surface of the CCD 214, so that signal charges corresponding to the brightness of the subject image are accumulated in the CCD 214. The timing of the CCD 214 is controlled by the DSP 433 and the CCD drive circuit 434, and the signal charges stored in the CCD 214 are discharged by the drive pulses output from the two circuits, and input to the image processing unit 431 including a noise removal circuit and a DC reproduction circuit. Is done. After analog processing such as noise removal and gain control is performed on the analog image signal by the image processing unit 431, the analog image signal is converted into a digital signal by the A / D conversion circuit 432.

The digitally converted signal is the above-mentioned DS
The image data is led to P433, where image pre-processing such as contour compensation and gamma correction is performed and temporarily stored in the buffer memory 436. Then, image data is exchanged between the CPU 439 and the buffer memory 436, a white balance adjustment value is obtained from the stored image data, and a white balance adjustment is performed by the DSP 433 based on the adjustment value. The subsequent image data is stored in the buffer memory 436 again.
Is stored in The image data stored in the buffer memory 436 is processed into image data for display by the DSP 433,
By writing this image data into the frame memory 435, a shooting screen called a freeze image is displayed on the display LCD 420.

The image data subjected to the image pre-processing as described above is further processed by the DSP 433 in JPEG format.
A format process (image post-processing) for compression is performed. Further, the data is compressed at a predetermined ratio according to the JPEG method, a predetermined data name is given by the CPU 439, and the time information from the timer 445 is stored in the flash memory or the like. It is recorded on a recording medium (PC card, CF card, etc.) 424.

FIG. 5 is a view for explaining a menu setting screen of the recording mode displayed on the display LCD 420 of the electronic still camera 1. When the menu button 16 in FIG. 1 is pressed in the recording mode, a menu setting screen as shown in FIG. 5A is displayed on the display LCD 420 of the electronic still camera 1. When the selection dial 17 or the zoom operation button 14 (which functions as a selection switch in the menu setting mode) is operated, for example, the item of “AE operation” is selected from the menu, and the release button 9 (the menu setting mode) is selected. When the “AE operation” is selected and pressed, the menu setting screen relating to the AE operation mode as shown in FIG. 5B is displayed on the display LCD 420. The AE operation mode is a “program mode” that determines an aperture value and a shutter speed (exposure time) under predetermined conditions in accordance with a detected brightness value of a subject in an exposure calculation performed by the CPU 439, and a brightness of the detected subject. "Aperture priority mode" that determines the shutter speed according to the value and the set aperture value, "Shutter priority mode" that determines the aperture value according to the brightness value of the detected subject and the set shutter speed, shooting "Off (manual)" in which the user determines the aperture value and shutter speed.

Selection dial 17 or zoom operation button 14
Is operated, for example, the item of "aperture priority mode" is selected from the menu. When the release button 9 is pressed and the item of “aperture priority mode” is selected and determined, an operation mode for determining the shutter speed in accordance with the detected luminance value and the set aperture value is selected.

When the "AF operation" item is selected from the menu by the selection dial 17 or the zoom operation button 14 (FIG. 6A), the release button 9 is depressed and the "AF operation" is pressed.
When “operation” is selected and determined, a menu setting screen relating to the AF operation mode as shown in FIG. The AF operation mode is a "continuous AF mode" in which the focus detection operation is always performed when the camera is set to the recording mode by the main switch 8, and when a half-press signal from the release button 9 is input to the CPU 439. "Single AF mode", which is performed only when the electronic still camera 1 does not perform the focus detection operation, and "Off (manual)" in which the photographer manually focuses.

Selection dial 17 or zoom operation button 14
Is operated, the item of "single AF mode" is selected from the menu. When the release button 9 is pressed and the item of “single AF mode” is selected and determined, an operation mode in which focus detection is performed only once when a half-press signal is input to the CPU 439 is selected.

These setting contents of the menu become effective when the menu button 16 is pressed again to return from the menu setting mode to the recording mode.

The menu setting as described above is used to set in detail the camera operation relating to the photographing functions such as the exposure correction, the metering method and the selection of the white balance adjustment value in addition to the AE mode and the AF mode described above. Things. During this menu setting mode, display LC
A menu screen as shown in FIGS. 5 and 6 is displayed on D420, and a screen of a subject image captured through the movable lens 2 is not displayed.

-Thinning-out reading-The display LCD 420 is a small liquid crystal display provided in the monitor unit 1b of the electronic still camera 1 as shown in FIG. 1, and displays the total number of pixels imaged by the CCD 214. The number of pixels is small. Therefore, when displaying the subject image picked up by the CCD 214 on the display LCD 420, the CCD 214
Is read out at a predetermined rate M in accordance with the display resolution of the display LCD 420.

FIG. 7 is a view for explaining the arrangement of pixels constituting the subject image picked up by the CCD 214 and the pixels which are thinned out and read in order to display the subject image on the display LCD 420. In FIG. 7, the pixels painted black are the display LCD.
Pixels which are decimated and read out for display at 420 are shown. For pixels picked up by the CCD 214, for example, M = 5, that is, read out at a ratio of one pixel for every five pixels in the vertical and horizontal directions of the pixel array. Is done.

When a color filter is provided on the CCD 214 for picking up a color image, when the R, G, B primary color filters are arranged in a Bayer array as shown in FIG. And G, Ye, C as shown in FIG.
In some cases, complementary color filters for y and Ma are arranged. FIG.
In both cases (a) and FIG. 8 (b), if pixels are read out by thinning out multiples of two in every two pixels in both the vertical and horizontal directions, such as every two pixels, the CCD 214 before the thinning is performed. The arrangement order of the color filters above matches the arrangement order of the color filters corresponding to the data read out by thinning (the Bayer array is maintained), so even if the thinning is performed, the colors before the thinning are reproduced. You. In FIGS. 8A and 8B, hatched pixels indicate pixel positions when one pixel is read out of five pixels.

The thinning-out reading is performed by the image processing unit 431 controlled by the CPU 439. That is, the image processing unit 431 displays the image signal output from the CCD 214
By sampling at a predetermined timing according to the display resolution of D420, the subject image captured by the CCD 214 is thinned out and read.

The thinning-out reading described above is performed in a so-called electronic viewfinder mode in which a subject image picked up by the CCD 214 is displayed as a through image, for example, when the above-described peaking process is performed to display the subject image on the display LCD 420. Is what is done. When a full-press signal is input by the release button 9 as in the recording operation described above, all the accumulated charges imaged by the CCD 214 are read out without thinning.

—Selection of Peaking Area— The peaking processing described above is performed for a specific area (hereinafter, referred to as a peaking area) selected from a plurality of areas obtained by dividing an object scene in a photographed subject image. This is performed on the subject image. FIG. 9 is a diagram illustrating an example of division in a case where an object scene captured by the electronic still camera 1 is divided into nine peaking regions, using a subject image displayed on the display LCD 420. When a half-press signal is input by the release button 9, as shown in FIG. 9A, the object field is selected as an area to be subjected to peaking processing from a total of nine areas vertically and horizontally divided into three equal parts. The peaking area fa thus displayed is enclosed and displayed. When a half-press signal is input by the release button 9, the peaking area fa initially displayed and enclosed is the area that was selected when the half-press signal was previously input by the release button 9.

In order to change the enclosed peaking area fa, the user uses the peaking area selection buttons 19a to 19d. Pressing the peaking area selection button 19a changes the peaking area fa to an area one level higher than the currently set area in FIG. 9A, and pressing the peaking area selection button 19b changes the area to the set area. The area is changed to one area below. Similarly, pressing the peaking area selection button 19c changes the area to the left of the area in which the peaking area fa is set, and pressing the peaking area selection button 19b causes one in the set area. It is changed to the right area.

The peaking area fa described above is used as an area for peaking processing, and also performs a detection operation (autofocus: AF) for automatically detecting a state of adjustment of the focal position by the movable lens 2 described later. Also used as an area. Note that the peaking area fa is used regardless of whether the electronic still camera 1 is set to the auto focus mode in which the AF operation is performed or the manual focus mode in which the photographer manually focuses. Is done. Peaking area selection button
Information of the peaking area fa set by 19a to 19d is
When a half-press signal from the release button 9 is input and stored in the CPU 439, the signal is read from the CPU 439 and displayed.
It is enclosed and displayed on D420. Note that the box display performed by the half-press signal is stopped when a predetermined time elapses after the half-press signal is input.

-Detection of Focus Adjustment State- The AF operation in the auto focus mode is performed as follows. When the image pickup signal picked up by the CCD 214 is thinned out and read as shown in FIG. 7, the contrast is detected from the image pickup signal corresponding to the set peaking area fa, and the movable lens 2 is detected based on the detected contrast. The state of adjustment of the focal position due to is detected. FIG.
Is an example of a graph showing the relationship between the pixel position on the CCD 214 corresponding to the set peaking area fa and the output value of the pixel. The graph shows a curve corresponding to the subject image. The greater the change in the curve, the higher the contrast of the subject image. Therefore, the adjustment state of the focal position is detected by the so-called hill-climbing method so that the contrast of the subject image becomes the highest, and the lens driving circuit 430 is driven to adjust the focal position of the movable lens 2 for focusing. FIG. 9B shows an in-focus display LCD 420.
It is a figure showing the subject picture displayed above. If the setting is made such that the focused subject image is peaked and displayed on the display LCD 420, the peaking process is performed only on the peaking area fa as shown in FIG. 9C. In FIG. 9C, the portion emphasized by the peaking processing is represented by a thick black line (excluding the surrounding frame indicating the peaking area fa).

-Electronic Zoom- The magnification of the subject image picked up by the electronic still camera 1 is changed by operating the zoom operation button 14.
The zoom magnification is determined by optical enlargement by the movable lens 2 and enlargement by electronic zoom processing in which image data captured by the CCD 214 is electronically interpolated and enlarged. When the zoom operation button 14 is operated to the telephoto side (T) when the zoom magnification is not enlarged, that is, when the magnification of the subject image is 1, the CPU 439 drives the zoom lens driving circuit 429 to move. Change the zoom magnification of lens 2 to be larger. The optical zoom magnification of the movable lens 2 becomes the limit, and the zoom operation button 14 is set to the telephoto side.
(T), the DSP 433 is instructed by the CPU 439.
Sets the electronic zoom magnification N, and performs the electronic zoom processing by interpolating the image data according to the set magnification N.

FIG. 11 is a view for explaining the electronic zoom operation when the electronic zoom magnification N is 2 times. FIG. 11A shows image data thinned out and read from the CCD 214 as shown in FIG. FIG. 3 is a diagram illustrating a pixel arrangement before zooming. As shown in FIG. 11A, the arrangement of the pixels and the corresponding color filters after the thinning-out reading is maintained in the Bayer arrangement similarly to the arrangement of the color filters before the thinning-out reading. The luminance signal and the color difference signal are calculated using the image data read out in such a thinned-out manner. FIG. 11B is a diagram showing luminance data calculated from the image data of FIG. 11A. For example, the luminance signals Y6,6 are pixel signals G6,6.
Is a luminance signal corresponding to. The DSP 433 converts the luminance signal of the central four pixels in FIG.
The pixel is interpolated so as to become a pixel, and the luminance signal after the interpolation is shown in FIG.
It is represented as (c). FIG. 11C is a diagram in which the luminance signal for the center four pixels in FIG. As described above, by interpolating the image data, the original image data can be electronically enlarged using the interpolated image data.

The electronic still camera 1 configured as described above
The photographing process in the recording mode will be described. FIG. 12 shows that the main switch 8 is operated and the recording / playback switch 4
67 is a flowchart conceptually showing a shooting process performed when the mode is switched to the recording mode. To the CPU 439, a zoom signal by operating the zoom operation button 14, a half-press operation signal by operating the release button 9, and a full-press operation signal are input, respectively. In step S101, when the zoom operation button 14 is operated to the telephoto side (T), the CPU 439 drives the zoom lens driving circuit 429 to optically increase the zoom magnification, and the optical magnification reaches a predetermined maximum value. When the zoom operation button 14 is operated to the telephoto side (T), the electronic zoom magnification N is determined according to the operation amount. Then, the shutter plate 208 is driven to set the opening 208b on the shutter plate 208 on the optical path, and the diaphragm plate 215 is driven to set all the openings 215a on the diaphragm plate 215 on the optical path. The electric charge is accumulated in the object and an object image is captured.

In step S102, the stored charges stored in the CCD 214 are thinned out to a predetermined ratio M according to the display resolution of the display LCD 420 and read out, whereby image data based on the captured image signal is read out. . The read image data is subjected to analog processing by the image processing unit 431 and converted into a digital signal by the A / D conversion circuit 432, and then subjected to predetermined image processing by the DSP 433. The contrast is detected from the image data, and the lens driving circuit 430 is driven based on the detected contrast to drive the movable lens 2.
Adjust the focus position of the. In step S103, peaking processing is performed on the image data corresponding to the set peaking area fa.

In step S104, when the electronic zoom magnification N is set to be larger than 1, interpolation processing is performed on the image data after the peaking processing so as to be N times vertically and horizontally. By writing the image data at the center of the image data after the interpolation processing to the frame memory 435, a through image that is electronically zoomed up by the peaking processing on the display LCD 420 is displayed. When the electronic zoom magnification N is set to 1, the image data after the peaking process is written to the frame memory 435 without performing the interpolation process for the electronic zoom, and the through image subjected to the peaking process is displayed on the display LCD 420. Is displayed.

In step S105, the brightness of the subject is detected from the image data, an exposure calculation is performed, and it is determined whether or not a full-press signal is input by the release button 9. When it is determined that the full-press signal has been input (Y in step S105), the process proceeds to step S106, and when it is determined that no full-press signal has been input (N in step S105), the process returns to step S102 to repeat the above operation.

In step S106, a predetermined opening of the diaphragm plate 215 is set on the optical path, and
The electric charge accumulated in 214 is discharged, and a so-called electronic shutter operation is performed. Here, the predetermined opening of the aperture plate 215 is an opening corresponding to an aperture value determined by exposure calculation. The CCD 214 is exposed for a predetermined time to accumulate electric charges, and a subject image is captured. The exposure time is controlled so that the time from when the electric charge is discharged to when the light path is blocked by the shutter plate 208 becomes the exposure time determined by the exposure calculation. After the exposure is completed, the complete light blocking portion 208a on the shutter plate 208 is set on the optical path, and the stored charges are read out from the CCD 214 without thinning out, so that image data based on the captured image signal is read out.

In step S107, the read image data is subjected to analog processing by the image processing unit 431,
The signal is converted into a digital signal by the D conversion circuit 432. The converted image data is stored in the buffer memory 436, and when the electronic zoom magnification is N, image data in an area of 1 / N in length and width around the center of the subject image is extracted. Step S
At 108, the DSP433
Performs predetermined image processing. In step S109,
The luminance signal and the color difference signal calculated by the image processing are
In the case of the electronic zoom magnification N, the interpolation processing is performed N times vertically and horizontally.

In step S110, the peaking processing mode is released, and in step S111, the image data after the interpolation processing is written into the frame memory 435, so that the electronic zoom-up frozen image in which the peaking processing is not performed is displayed on the display LCD 420. Is done. However, if the electronic zoom magnification N is set to 1x,
Since interpolation processing for electronic zoom is not performed in step S109, the through image is not electronically zoomed up.
In step S112, the data after the image processing is compressed in a predetermined format and recorded on the memory card 424. With the above processing, a series of photographing processing according to FIG. 12 ends.

-Reproduction Operation- When the main switch 8 is switched to the reproduction mode: PLAY position, the electronic still camera 1 is switched to the reproduction mode when the power is turned on. When there is image data recorded on a recording medium 424 such as a memory card, the last image data recorded among the recorded image data is
Read to 439. The read image data is sent to the buffer memory 436, processed by the DSP 433 into image data for display, and displayed on the display LCD 420 as a reproduced image 1-1 as shown in FIG.

When a plurality of image data are recorded on the recording medium 424, the peaking area selection button 19b (which functions as a frame return switch during the playback mode) is operated to display the displayed image. One frame ago,
That is, the image data previously recorded in time series is read from the recording medium 424 and displayed on the display LCD 420 (image 2-1 in FIG. 13). Continue peaking area selection button 19b
Each time is operated, the frame of the image data to be reproduced is returned, and the display LC is changed as shown in the image 3-1 and the image 4-1 in FIG.
Data recorded immediately before the image data displayed on D420 is read out and displayed on display LCD420. All frames are played back and the peaking button
When 19b is operated, the image data of the image 1-1 that has been read first is read again from the recording medium 424 and is displayed on the display LCD 4.
Appears on 20.

When the peaking area selection button 19a (which functions as a frame feed switch in the playback mode) is operated, an image recorded one frame after the displayed image, that is, an image recorded later in time series. The data is read from the recording medium 424 and displayed on the display LCD 420. For example, in the case where the image 3-1 is displayed in FIG. 13 as an example, the image 2-1 is read from the recording medium 424 and displayed on the display LCD 420 by operating the peaking area selection button 19a once. Will be displayed. Each time the peaking area selection button 19a is subsequently operated, the image data to be reproduced is advanced by one frame.
.., The data recorded immediately after the image data displayed on the display LCD 420 is read out and displayed on the display LCD 42.
Displayed as 0.

In FIG. 13, when the peaking area selection button 19d (which functions as a display changeover switch during the reproduction mode) is operated while the image 2-1 is displayed, the peaking processing mode is set, and the contrast is set by the peaking processing. Image 2-2 with the high part of the image highlighted L
Displayed on CD420. When the peaking area selection button 19d is subsequently operated, the peaking processing mode is released, and the recording information such as the shutter speed, the aperture value, the metering value, and the distance to the subject are superimposed on the image from which the peaking processing has been released. Image 2-3 is displayed.

In FIG. 13, when the peaking area selection button 19c (which functions as a display changeover switch during the reproduction mode) is operated when the image 2-3 is displayed,
The display of the recording information such as the superimposed shutter speed, aperture value, metering value, and distance to the subject is released, and the image 2-2 that has been set to the peaking processing mode and subjected to the emphasis processing is displayed on the display LCD 420. Is displayed. When the peaking area selection button 19c is subsequently operated, the peaking processing mode is canceled and the image 2-1 is displayed.

Displaying the image subjected to the peaking process by the display changeover switch (image * -2 in FIG. 13) or displaying the image in which the recorded information is superimposed (image * -3 in FIG. 13) The above-described frame return switch and frame advance switch may be operated. Here, Image * -2 is Image 1-2, Image 2-2, Image 3-2 and Image 4-2
, And is an image on which the peaking processing mode has been set and the emphasis processing has been performed. Image * -3 represents any one of image 1-3, image 2-3, image 3-3, and image 4-3, and the recording information is superimposed on the image from which the peaking processing has been canceled. It is an image. For example, when the peaking area selection button 19b (which functions as a frame return switch in the playback mode) is operated while the image 3-3 in FIG. 13 is being displayed, one frame before the displayed image being displayed, that is, The image data previously recorded in time series is read from the recording medium 424, and the recording information such as the shutter speed, the aperture value, the photometric value, and the distance to the subject is superimposed and displayed on the display LCD 420 (FIG. 13 images 4-3).

When the peaking area selection button 19a (which functions as a frame feed switch during the playback mode) is operated while the image 2-2 in FIG. 13 is displayed,
One frame after the displayed image, that is, image data recorded later in time series is read from the recording medium 424, and the image 1-2 on which the peaking process has been performed is displayed LC.
Displayed on D420.

As described above, by operating the peaking area selection buttons 19a and 19b, the image 1- * shown in FIG.
To image 4- * on a recording medium 424 for each frame.
And the peaking area selection buttons 19c, 19
By operating d, it is possible to perform peaking processing as shown in the images * -1 to * -3 in FIG. 13 and to superimpose the recorded information. Where image 1- *
Represents one of the images 1-1, 1-2 and 1-3 in FIG. Further, the image * -1 represents any one of the images 1-1, 2-1, 3-1 and 4-1 in FIG. The peaking display in the playback mode is based on the peaking area fa set in the recording mode.
Irrespective of this, the high contrast part of the entire image displayed on the display LCD 420 is emphasized and displayed.

The features of the first embodiment will be summarized. (1) Peaking processing (step S1 in FIG. 12) is performed on the image data based on the imaging signal read from the CCD 214.
03), and then the image data after the peaking process is
The image is interpolated twice and displayed (step S104 in FIG. 12). Therefore, if the subject image captured by the CCD 214 is the same, the same portion of the image is subjected to the peaking process regardless of the electronic zoom magnification N. That is, since the electronic zoom image is created by interpolating the image data after the peaking process, the image data in which the enhancement by the peaking process is continuous before the interpolation becomes the image data in which the enhancement is continuous after the interpolation. . As a result, the portion emphasized by the peaking processing of the enlarged image by the electronic zoom does not jump. (2) After the release button 9 is fully depressed, there is no need to perform focusing or the like on the captured image, so the peaking processing mode is canceled in step S110 (FIG. 12). As a result, step S1
At 11, a natural freeze image without peaking processing can be displayed on the display LCD 420. (3) In the peaking process, a luminance signal Y calculated from an image signal picked up by the CCD 214 is differentiated, and the result of the differential operation is added to the original luminance signal Y to display the LCD.
Since the image is displayed on 420, as the contrast of the outline of the subject image becomes clearer, the portion is emphasized black or white. Further, when the result of the differential operation is larger than a predetermined value, the color difference signal RY and the color difference signal BY
Is set to 0, so that particularly high contrast portions are displayed in white and visibility is improved. (4) In the electronic viewfinder mode, the CCD
The signal charge imaged and accumulated by 214 is thinned out to a predetermined ratio M according to the display resolution of the display LCD 420 and read out. Therefore, the number of data to be read is smaller than when all signal charges are read, and the buffer memory
The use area of 436 can be reduced. Furthermore, CP
Since the processing load on the U439 and the DSP 433 can be reduced, the processing time and the power consumption can be reduced. (5) Autofocus (AF) operation for automatically detecting the state of adjustment of the focal position by the movable lens 2, and
The peaking process in (3) is performed using the image data thinned out and read at a predetermined ratio M in (4). That is, contrast detection during the AF operation is performed using the data displayed on the display LCD 420, and when focus is achieved, a portion of the displayed data where the contrast is high is emphasized and displayed. Therefore, the display L
It is easy to check the focused part on CD420. (6) A peaking area is selected from among a plurality of divided areas, and an autofocus (AF) operation is performed on a subject image located in the peaking area fa, and peaking is performed on a subject image located in the peaking area fa. Processing was performed. As a result, it is not necessary to perform the AF operation and the peaking process on the entire object field, so that the effect of reducing the processing time can be obtained. In addition, when checking whether or not the main subject is in focus is performed on the display LCD 420, only the peaking area fa including the main subject needs to be checked.

In the above description, the manual focus (MF) mode and the auto focus mode (continuous AF (CAF) mode and the single A
F (SAF) mode), but instead of the menu setting, a CAF / SAF / MF switch 46 shown in FIG.
Switching may be performed by 3.

In the description of the peaking process described above, a portion having a high contrast, such as an outline of a subject image, is displayed with high brightness and emphasized white. However, instead of white, a color complementary to the background may be displayed. Good. In addition, white and black may be displayed by blinking. In this way, even when the background color of the subject image is white and the emphasized white portion is inconspicuous, the effect of making the emphasized portion easier to see by performing the complementary color display or the blinking black and white display is obtained.

In the above description of the peaking process, the aperture value (the aperture 215a of the aperture plate 215 set in the optical path)
~ 215 g) regardless of the peaking process.
That is, in the peaking process, it is determined whether or not the color difference signals RY and BY are replaced with 0 depending on whether or not the luminance signal value after the differential operation is larger than a predetermined value. If the predetermined value is changed according to the aperture value, the intensity of the peaking process can be changed according to the depth of field. For example, when the aperture is wide open and the depth of field is shallow, the outline is strongly emphasized. When the aperture is narrowed down, the depth of field is deep and the outline is weakly emphasized. In this way, when there are many in-focus portions with a large depth of field, all of them are emphasized by the peaking process, and the entire screen is prevented from being displayed with high brightness and glare.

Further, the predetermined value may be changed according to the brightness of the background of the subject image. If the outline is strongly emphasized when the background is bright, and the outline is emphasized weakly when the background is dark, an effect is obtained in which the emphasized portion is easy to see even when the brightness of the background changes.

-Second Embodiment- In the second embodiment, the first embodiment performs a peaking process in step S103 in FIG. 12 and then performs an interpolation process in step S104 to display a through image. On the other hand, the second embodiment is different from step S103B in FIG.
Is different in that interpolation processing is performed and then peaking processing is performed in step S104B to display a through image. FIG. 14 is a flowchart illustrating the concept of the photographing process according to the second embodiment. The differences from the flowchart of FIG. 13 are steps S103B and S104B, so only those steps will be described.

In step S103B, when the electronic zoom magnification N is set to be larger than 1, the DSP 43
Interpolation processing is performed so that the image data after the image processing by 3 becomes N times vertically and horizontally. Among the image data after the interpolation processing, the image data at the center is prepared as data for live view display. When the electronic zoom magnification N is set to 1, the image data after the image processing by the DSP 433 is prepared as data for displaying a through image without performing the interpolation processing.

In step S104B, the image data corresponding to the set peaking area fa is extracted and thinned out at a ratio of one out of N out of the through image display data. Subsequently, peaking processing is performed on the thinned and extracted image data. By writing the image data after the peaking processing to the frame memory 435, the enlarged image is enlarged by the electronic zoom, and the through image emphasized by the peaking processing is displayed on the display LCD 420.
That is, of the live view image display data, the thinned and extracted image data is replaced with the peaked data and displayed on the display LCD 420.

The features of the second embodiment will be summarized. Interpolation processing (step S103B in FIG. 14) is performed on the image data based on the image pickup signal read from the CCD 214 so that the image data becomes N times vertically and horizontally. Among the image data after the interpolation processing, the image data corresponding to the peaking area fa is thinned out at a rate of one out of N pieces to perform the peaking processing (Step S104B in FIG. 14). In general, when the electronic zoom magnification N is set to be larger than 1, high-frequency components included in the image data are lost by interpolating the image data N times vertically and horizontally, and as a result, the differential operation value becomes small. However, when the differential operation is performed by thinning out the interpolated image data to a ratio of one to N, the differential operation value can be increased as in the case of performing the differential operation before the interpolation. Furthermore, since the peaking process is performed by extracting data thinned out at a rate of one out of N data, the processing time is shortened because the amount of calculation is smaller than in the case where the peaking process is performed using all data without thinning. it can.

In the above description, the electronic still camera has been described. However, the present invention can be applied to a video camera capable of performing peaking processing and electronic zoom processing.

The correspondence between each component in the claims and each component in the embodiment of the invention will be described. The CCD 214 is displayed on the imaging device, the DSP 433 is displayed on the signal processing means and the magnification changing means, and the display LCD 420 is displayed on the display. Each corresponds to a means.

[0075]

According to the present invention as described in detail above, the following effects can be obtained. (1) According to the first aspect of the present invention, the image processing apparatus includes a signal processing unit that enhances an image pickup signal picked up by the image pickup device, and a magnification change unit that changes a magnification of an image based on the image pickup signal independently of the signal processing unit. Therefore, for example, it is possible to change the image magnification while enhancing the outline of the subject image displayed on the monitor display means, and an effect of improving the operability of the camera is obtained. (2) According to the second aspect of the invention, the image magnification is changed after the imaging signal is emphasized by the signal processing means. As a result, an effect is obtained that the contour enhancement of the subject image is always performed under the same condition regardless of the enlargement of the image. (3) According to the third aspect of the invention, when the imaging signal is emphasized after the magnification is changed by the magnification changing means, the imaging signal whose magnification has been changed is thinned out and emphasized. Therefore, for example, even when the high-frequency component included in the imaging signal decreases due to the enlargement of the image, the contour of the subject image can be enhanced. In particular, according to the invention of claim 4, when the magnification is changed by N times by the magnification changing means, the imaging signal is thinned out and emphasized so as to become 1 / N, so that the contour of the subject image is irrespective of the magnification N. The signal can be emphasized, and the number of signals to be emphasized is reduced as compared with the case where no thinning is performed, so that the effect of reducing the processing time can be obtained.

[Brief description of the drawings]

FIGS. 1A and 1B are views showing an external appearance of an electronic still camera according to an embodiment when the electronic still camera is stored and when the electronic still camera is carried, wherein FIG. 1A is a view seen from above, and FIG.

FIGS. 2A and 2B are views showing the appearance of the camera of FIG. 1 during normal shooting, wherein FIG. 2A is a view from the front, FIG. 2B is a view from the top, and FIG. It is.

FIG. 3 is a diagram showing circuit blocks of the electronic still camera according to the first embodiment.

FIG. 4 is a perspective view of a lens group.

FIG. 5 is a diagram illustrating the setting of an AE operation on a menu setting screen.

FIG. 6 is a diagram for explaining setting of an AF operation on a menu setting screen.

FIG. 7 is a diagram for explaining a pixel array forming a subject image picked up by a CCD and pixels read out by thinning.

8A is a diagram showing an example of the arrangement of primary color filters provided on a CCD, and FIG. 8B is a diagram showing an example of an arrangement of complementary color filters provided on a CCD.

9A is a diagram for explaining an example of division when an object scene to be imaged is divided into nine peaking regions, FIG. 9B is a diagram showing a focused state, and FIG. FIG.

FIG. 10 is a diagram illustrating a relationship between a position of each pixel detected on the CCD and an output value of each pixel.

11A and 11B are diagrams for explaining an electronic zoom operation when the electronic zoom magnification N is 2 times, where FIG. 11A shows a pixel arrangement of image data before electronic zoom enlargement, and FIG. 11B shows an image of FIG. The luminance data calculated from the data, (c) is obtained by interpolating the luminance signal of the central four pixels of (b) twice vertically and horizontally.

FIG. 12 is a flowchart illustrating a concept of a photographing process according to the first embodiment.

FIG. 13 is a diagram illustrating a reproduced image displayed in a reproduction mode.

FIG. 14 is a flowchart illustrating the concept of a shooting process according to the second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electronic still camera, 2 ... Movable lens, 4 ... Flashing device, 8 ... Main switch, 9 ... Release button, 12 ...
Shooting distance mode button, 14 ... zoom operation button,
15: Monitor display button, 16: Menu button, 17: Selection dial, 19a-19d ...
Peaking area selection button, 21 ... lens group, 214 ... C
CD, 420 ... display LCD, 429
… Zoom lens drive circuit, 430… Lens drive circuit, 431… Image processing unit, 435… Frame memory, 436… Buffer memory, 43
9… CPU, 471… Switch, 48
0 ... power supply circuit, 463 ... CAF / SAF / MF selector switch,
464: AE mode switch, 467: Record / playback switch, 468: Continuous shooting mode switch,
480: Power supply circuit, fa: Peaking area

Claims (4)

[Claims] An image pickup device for picking up an image of a subject through a photographing lens; signal processing means for performing predetermined processing on an image pickup signal output from the image pickup device to emphasize the image pickup signal; and independent of the signal processing means. An electronic camera, comprising: a magnification changing unit configured to change a magnification of an image based on the imaging signal; and a display unit configured to display an image based on the imaging signal. 2. An image pickup apparatus for picking up an image of a subject through a photographing lens, signal processing means for performing predetermined processing on an image pickup signal output from the image pickup apparatus to emphasize the image pickup signal, and outputting from the signal processing means. An electronic camera comprising: a magnification changing unit configured to change a magnification of an image based on a captured image signal; and a display unit configured to display an image based on the imaging signal output from the magnification changing unit. 3. An imaging device for capturing an image of a subject through a photographic lens, magnification changing means for changing the magnification of an image based on an imaging signal output from the imaging device, and thinning out the imaging signal output from the magnification changing device. A signal processing unit that performs predetermined processing on the image signal after the thinning to emphasize the image signal after the thinning, and a display unit that displays an image based on the image signal output from the signal processing unit. And electronic camera. 4. The electronic camera according to claim 3, wherein the thinning of the imaging signal output from the magnification changing means is performed by:
An electronic camera, wherein the ratio is set to 1 / (the magnification changed by the magnification changing means).