JP2000156816A - Device and method for emphasizing edge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to obtain a more natural image by edge emphasis suited to the contents of a subject. SOLUTION: The edge emphasis device is provided with an edge extraction filter 6 to which a part of a Y signal generated from an image signal is inputted, a core ring circuit 7, an amplifier 8, and an adder 9 and constituted so as to superpose a luminance signal processed by respective components to the original image signal. A CPU 10 controls the gain of the amplifier 8 to the gain corresponding to the contents of the subject judged based on the range finding data of a range finder sensor 11 so that the degree of edge emphasis is suited to the contents of the subject.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an edge enhancement device and an edge enhancement method suitable for use in a digital camera.

[0002]

2. Description of the Related Art Conventionally, for example, in a digital camera, a digital video camera, or the like, in order to obtain more natural image data, an edge portion of an object, that is, a contour portion, is determined with respect to image data of a captured object. Is generally performed. Such edge enhancement is performed by, for example, increasing the luminance of an edge portion of a predetermined width of a subject by a certain amount.

[0003]

However, in the conventional image processing, the degree of emphasizing the edge of the subject is always constant, so that the degree of emphasis is, for example, short-range photography or telephoto photography. If the main subject is set in accordance with a coarse image such as a portrait having a large size in the screen as in the case where the main subject is photographed, for example, a long-range shooting or a wide-angle shooting is performed. In contrast, small images such as landscape photographs in which a large number of relatively small subjects exist on the screen cause insufficient edge enhancement, and conversely, if they are set in accordance with fine images such as landscape photographs, coarse images such as portraits Thus, there is a problem that a sufficient effect cannot be obtained for all subjects having different contents, such as excessive edge enhancement.

The present invention has been made in view of such a conventional problem, and an edge enhancement device and an edge enhancement device capable of obtaining a more natural image by performing edge enhancement suitable for the contents of a subject. The aim is to provide a method.

[0005]

According to another aspect of the present invention, there is provided an edge enhancing apparatus for detecting an edge of a subject with respect to an image signal generated by an imaging device which captures a subject image as image information by an imaging element. Edge emphasizing means for emphasizing; acquiring means for acquiring photographing distance information of the subject in the image signal; and changing the degree of edge emphasis by the edge emphasizing means in accordance with the photographing distance information acquired by the acquiring means. And a control means for performing the control. In such a configuration, if the acquired shooting distance information of the subject is different, the edge of the subject is emphasized with a different degree of enhancement according to the shooting distance information. That is, if there is a difference in the quality of the subject such as a coarse image such as a portrait or a fine image such as a landscape photograph, the edge of the subject is emphasized with a different degree of enhancement according to the difference.

Further, in the edge emphasizing device according to claim 2, the acquisition means acquires zoom magnification information in addition to the photography distance information, and the control means acquires the photography distance information acquired by the acquisition means. The degree of edge emphasis by the edge emphasizing means is changed according to the zoom magnification information. In such a configuration, two different types of information, ie, shooting distance information and zoom magnification information,
The above-described difference in the content of the subject can be accurately determined.

According to a third aspect of the present invention, there is provided an edge enhancing device for enhancing an edge of a subject with respect to an image signal generated by an imaging device which captures a subject image as image information by an imaging device; An acquisition unit for acquiring zoom magnification information and a control unit for changing the degree of edge enhancement by the edge enhancement unit in accordance with the zoom magnification information acquired by the acquisition unit are provided. In such a configuration, if the acquired zoom magnification information of the subject is different, the edge of the subject is emphasized with a different degree of enhancement according to the zoom magnification information. That is, if there is a difference in the content of the subject such as a coarse image such as a portrait or a fine image such as a landscape photograph, the edge of the subject is emphasized with a different degree of enhancement according to the difference.

According to a fourth aspect of the present invention, there is provided an edge enhancement device for enhancing an edge of a subject with respect to an image signal generated by an imaging device which captures a subject image as image information by an imaging element; And a control means for changing the degree of edge enhancement by the edge enhancement means in accordance with the amount of high frequency components acquired by the acquisition means. And In such a configuration,
Based on the amount of the high frequency component of the spatial frequency in the image signal, differences in the content of the subject such as a coarse image such as a portrait or a fine image such as a landscape photograph are directly determined from each image, and the difference according to the determination result is determined. The edge of the subject is emphasized with the degree of emphasis.

Further, in the edge emphasizing device according to a fifth aspect, the control means causes the edge emphasizing means to perform an emphasizing process for changing a luminance of an edge portion of the subject. In such a configuration, the control means changes the brightness of the edge portion of the subject according to the difference in the content of the subject. That is, the edge enhancement of the subject according to the difference in the content of the subject is performed by changing the shading of the edge portion.

Further, in the edge enhancement device according to the present invention, the control means causes the edge enhancement means to change a width of an edge portion of the subject to be enhanced. In such a configuration, the control means changes the width of the edge portion of the subject according to the difference in the content of the subject. That is, the edge enhancement of the subject according to the difference in the content of the subject is performed by changing the width of the edge portion.

Further, in the edge emphasizing device according to the present invention, a plurality of different edge extracting filters are further provided, and the control means switches and selects the edge extracting filter to select an edge portion of the object to be emphasized. The width was changed. In such a configuration, the width of the edge portion of the subject is changed according to the difference between the selected edge extraction filters.

According to another aspect of the present invention, in the method for enhancing the edge of a subject with respect to an image signal generated by an imaging device which captures a subject image as image information by an image sensor, the image enhancement is performed prior to the edge enhancement of the subject. It is determined whether or not the image is a fine image, and the degree of edge enhancement is changed according to the result of the determination. In such a method, if the image determined in advance is a fine image, that is, if the quality of the image is different, the edge enhancement of the subject is performed with a different enhancement degree according to the result.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a digital camera having an autofocus function according to a first embodiment of the present invention. The CCD 1 serving as an imaging element captures a subject image formed by a lens (not shown). The image signals picked up by the CCD 1 are sequentially converted to A based on a predetermined timing signal.
Is converted into a digital image signal by the A / D converter 2 and YU
The signal is sent to the V conversion circuit 3. The YUV conversion circuit 3 generates a luminance signal (Y signal) and two color signals (Cb signal, Cr signal) from the input signal. Y, Cb, Cr generated
Are sent to the edge emphasizing circuit 4, where the edge emphasizing circuit 4 performs edge emphasizing processing for emphasizing the edge of the subject, and then stores the image data in the memory 5 through compression processing and the like.

FIG. 2 is a block diagram showing the edge emphasis circuit 4. The edge emphasis circuit 4 includes an edge extraction filter 6, a coring circuit 7, an amplifier 8, and an adder 9. 3A and 3B are diagrams showing signal waveforms at various parts of the edge emphasizing circuit 4. FIG. 3A shows the Y signal input from the YUV conversion circuit 3, and FIG. 3B shows the edge extracting filter 6. (C) is the output signal of the coring circuit 7, (d) is the output signal of the amplifier 8,
FIG. 7E shows the output signal of the adder 9.

The edge extraction filter 6 is a kind of high-pass filter or mask filter. The edge extraction filter 6 receives a Y signal from the YUV conversion circuit 3 and, for each predetermined pixel unit, for example, a 5 × 5 pixel unit (see FIG. 10A). ), The amplitude of the Y signal is increased or decreased by a predetermined width in accordance with the luminance of the central pixel and peripheral pixels adjacent thereto (edge extraction is performed). The coring circuit 7 removes noise by cutting the amplitude of the output signal of the edge extraction filter 6 to a constant coring level L. The amplifier 8 amplifies the output signal of the coring circuit 7 and sends it to the adder 9. Then, the adder 9 adds the luminance signal amplified by the amplifier 8 to the output signal of the YUV conversion circuit 3 to emphasize the edge of the subject. The amplifier 8 is capable of variably controlling the gain, and controls the CPU 1 that controls each part of the digital camera.
The gain is varied by a gain control signal sent from 0. The CPU 10 calculates a subject distance (photographing distance) at the time of photographing.
The gain of the amplifier 8 is controlled in accordance with the program recorded in the ROM 12 based on the distance measurement data sent from the auto-focus distance measurement sensor 11 for measuring the distance. That is, in the present embodiment, the edge emphasizing circuit 4 and the CPU
10. The edge enhancement device of the present invention is constituted by the distance measuring sensor 11.

FIG. 4 is a flowchart showing an operation related to the gain adjustment processing of the amplifier 8 performed by the CPU 10 at the time of photographing when the distance measuring distance of the distance measuring sensor 11 is 0.25 m to ∞. That is, when the photographing operation is performed (YES in step SA1), the CPU 10 determines the subject distance K based on the distance measurement data sent from the distance measurement sensor 11 (step SA2).
If the difference is less than the amplifier 8 as shown in FIG.
Is set to 1 (YES in step SA3,
Step SA4). Accordingly, the image signal output from the adder 9 is a signal in which the amplitude of the edge portion is amplified by a fixed amount as a reference. The subject distance K
Is greater than or equal to 1 m and less than 20 m, the gain is set to double as shown in FIG. 5B (YES in step SA5, step SA6). Accordingly, even if the Y signal input to the edge extraction filter 6 is the same, the image signal output from the adder 9 is a signal whose amplitude at the edge portion is doubled. When the subject distance K is 20 m or more, the gain is set to triple as shown in FIG. 5C (NO in step SA5,
Step SA7). Accordingly, the edge extraction filter 6
Are the same, the image signal output from the adder 9 is a signal whose amplitude at the edge is tripled. That is, as the subject distance increases, the luminance of the edge portion of the subject (the degree of emphasis of the edge) changes to three levels of “weak”, “medium”, and “strong”. In other words, the density of the edge portion of the subject gradually increases.

In general, the subject distance is short (0.25 m to 1 m) in a portrait or the like, and the subject distance is long (20 m or more) in a landscape photograph or the like. Therefore, according to the present embodiment, edges are not excessively emphasized by reducing the degree of edge enhancement in a coarse image in which the size of the main subject in the screen is large, such as a portrait. Natural images can be obtained. In addition, by increasing the degree of edge emphasis in a fine image such as a landscape photograph where many relatively small subjects exist on the screen,
A natural image with fine parts clearly expressed is obtained. [Second Embodiment] Next, a second embodiment of the present invention will be described. In the present embodiment, the digital camera shown in FIG. 1 and FIG.
In the configuration in which U10 has information on the zoom magnification, the above-described gain adjustment of the amplifier 8 is performed based on the subject distance and the zoom magnification. Hereinafter, in the present embodiment, an operation related to another gain adjustment process performed by the CPU 10 at the time of shooting will be described with reference to the flowchart of FIG. The range of usable zoom magnification is a magnification equivalent to 32 mm to 64 mm in 35 mm film conversion.

That is, when the photographing operation is performed (YES in step SB1), the CPU 10 determines whether or not the zoom magnification at that time is a telephoto magnification corresponding to 48 mm or more (step SB2). Here, if the zoom magnification is on the telephoto side, the switching distance N, which is the subject distance at which the gain is changed between 1 × and 2 × (“weak” and “medium”)
Is set to 1 m (step SB3), and if the zoom magnification is a magnification corresponding to the wide side, that is, less than 48 mm, the switching distance N is set to 0.5 m (step SB4). And
The subject distance K is determined based on the distance measurement data sent from the distance measurement sensor 11 (step SB5), and is determined to be 0.25 m.
As described above, when the switching distance is shorter than N, the gain of the amplifier 8 is increased by 1 (YES in step SB6, step SB
7) If the switching distance is not less than N and less than 20 m, the gain is set to double (YES in step SB8, step SB9), and if it is not less than 20 m, the gain is set to triple (NO in step SB8, step SB8). SB1
0).

As a result, as shown in FIG. 7, when the zoom magnification is on the telephoto side, the same gain adjustment as in the first embodiment is performed. On the other hand, when the zoom magnification is on the wide side, for example, when the subject distance is 0.5
When the distance is between m and 1 m, the gain of the amplifier 8 is controlled to be twice, and the degree of edge enhancement is set to “medium”. In other words, even if the subject distance is the same, if the zoom magnification is on the wide side, it is determined that the image is a fine image in which a number of relatively small subjects exist in the screen, and edge enhancement suitable for the content of the subject is performed. Will be Therefore, as compared with the first embodiment, the content of the subject can be more accurately determined, so that edge emphasis more suitable for the content of the subject can be performed.

In the first and second embodiments, the amplifier 8 is provided with three setting gains. However, as a matter of course, the setting gain may be set to four or more levels, and the subject distance may be increased. (And / or zoom magnification), the gain may be changed steplessly.

In addition to the above-described gain adjustment processing, the CPU 10 may perform a gain adjustment processing based on only the zoom magnification. For example, as shown in FIG. 8, regardless of the subject distance, the gain of the amplifier 8 is set to “1 ×” when the zoom magnification is “tele” and the amplifier is set to “1” when the zoom magnification is “wide”. The set gain of No. 8 is set to “2 times” (or 2.5 times or the like), and the gain adjustment processing is performed. Also in such processing, under conditions where it is expected that the photographed object is a coarse image such as a portrait in which the size of the main subject in the screen is large, the degree of edge enhancement is reduced, and Under the condition that it is expected that the image is a fine image including a large number of relatively small subjects, the degree of edge enhancement can be increased. Therefore, although the accuracy of determining the content of the subject is reduced as compared with the above-described second embodiment, a more natural image quality can be obtained as compared with the conventional case where the degree of enhancement is always constant. Also in this gain adjustment process, a more natural image quality can be obtained by increasing the number of zoom magnification steps that determine the set gain of the amplifier 8 or by changing the gain steplessly in proportion to the zoom magnification. I can expect that. [Third Embodiment] Next, a third embodiment of the present invention will be described. FIG. 9 is a block diagram showing another edge enhancement circuit 14 that performs edge enhancement processing in another digital camera having the schematic configuration shown in FIG. Hereinafter, the same components are denoted by the same reference numerals, description thereof will be omitted, and only different portions will be described. That is, the edge emphasizing circuit 14 of the present embodiment includes a first edge extracting filter 15 and a second edge extracting filter for performing an edge extracting process on the Y signal in the same manner as described in the first embodiment. 16 are provided. Both edge extraction filters 15 and 16 are connected to the above-described YUV conversion circuit 3 and coring circuit 7 via a pair of changeover switches 17 and 18 respectively connected to the input side and output side of each other.

The first edge extraction filter 15 is shown in FIG.
As shown in (a), for each unit of 5 × 5 pixels, the amplitude of the Y signal is increased or decreased by a predetermined width in accordance with the luminance of the center pixel and surrounding pixels adjacent thereto. As shown in FIG. 10B, edge extraction for two pixels can be performed. Similarly, the second edge extraction filter 16 increases or decreases the amplitude of the Y signal by a predetermined width in units of 3 × 3 pixels as shown in FIG. 11A, and by using this, As shown in FIG. 11B, it is possible to extract an edge for one pixel. That is, the first edge extraction filter 15 and the second edge extraction filter 16 can extract an edge having a smaller width in the latter than in the former.

The pair of changeover switches 17, 18
Operates based on a switching signal sent from the CPU 10 that controls each section of the digital camera, and closes a circuit on one of the first edge extraction filter 15 and the second edge extraction filter 16. The control of the pair of changeover switches 17 and 18 by the CPU 10 is performed according to a program recorded in the ROM 12 based on distance measurement data sent from the distance measurement sensor 11. That is, in the present embodiment, the subject distance determined from the distance measurement data is
When the shortest is 0.25 m or more and less than 1 m, the circuit on the first edge extraction filter 15 side is closed, and when it is 1 m or more, the circuit on the second edge extraction filter 16 is closed.

Therefore, in the present embodiment having the above configuration, as shown in FIG. 12, the object distance at the time of photographing is not less than 0.25 m and less than 1 m, and the photographed image is a coarse image. When it can be determined that, the image signal output from the coring circuit 7 via the first edge extraction filter 15 and the image signal output from the adder 9 have thick edge components for two pixels.
Therefore, in portraits and the like in close-up photography, a more natural image can be obtained by increasing the edge width of the subject to be emphasized. When the object distance at the time of photographing is 1 m or more and it can be determined that the photographed image is a fine image, the image signal output from the coring circuit 7 through the second edge extraction filter 16 and the adder The image signal output from 9 has a thin edge component for one pixel. Therefore, in a landscape photograph or the like, which is a group of fine subjects in distant view shooting, by narrowing the edge width of the subject to be emphasized, a more natural image in which the fine portions appear clearly can be obtained.

In this embodiment, the first edge extraction filter 1 is used based only on the subject distance at the time of photographing.
5 and the use of the second edge extraction filter 16 (the width of the edge to be emphasized) is switched. As in the case of the second embodiment, the digital camera has a zoom function. If the CPU 10 has information on the zoom magnification, the width of the edge may be switched based on the subject distance and the zoom magnification. In that case, the content of the subject can be more accurately determined, so that a more natural image quality can be obtained. Further, the width of the edge may be switched based only on the zoom magnification. Further, the second and third embodiments may be combined. That is, filter switching and gain switching may be performed according to the subject distance and / or the zoom magnification. [Fourth Embodiment] Next, a fourth embodiment of the present invention will be described. FIG. 13 is a block diagram showing a schematic configuration of a digital camera according to the present invention. This digital camera includes a CCD 1, an A / D converter 2, a YUV conversion circuit 3, an edge emphasizing circuit 14, and a memory 5, similarly to the digital camera shown in FIG. 1, and an image signal (Y signal) output from the YUV conversion circuit 3. Is configured to be sent to the spatial frequency detection circuit 21 and input to the edge emphasizing circuit 4 via the full-wave rectifier circuit 22. The spatial frequency detection circuit 21 detects a change in shading for each line in the image signal. The spatial frequency of the output signal is determined when the subject image captured by the CCD 1 is a fine image such as a landscape photograph. 15A, the amount of the high-frequency component becomes large, and when the subject image is a coarse image such as a portrait, the amount of the high-frequency component becomes small as shown in FIG. Become. The full-wave rectifier circuit 22 is a circuit for detecting the amount of the high-frequency component, and sends a detection signal reflecting the amount of the high-frequency component to the CPU 10. The CPU 10 controls the operation of the edge emphasizing circuit 14 according to the program stored in the ROM 12 based on the detection signal.

FIG. 14 shows the edge emphasis circuit 14.
FIG. As is apparent from the figure, the circuit detects the detection signal of the full-wave
Are the same as those described in the third embodiment except that they are input to. Then, based on the amount of the high-frequency component of the spatial frequency indicated by the detection signal of the full-wave rectifier circuit 22, the CPU 10 follows the program recorded in the ROM 12 when the amount is larger than the determined switching amount (FIG. 15a), the circuit on the second edge extraction filter 16 side is closed, and when the amount of the high frequency component is smaller than the switching amount (see FIG. 15b), the first edge extraction filter 16 is closed.
Is performed to close the circuit on the edge extraction filter 15 side. That is, the spatial frequency detection circuit 21 and the full-wave rectification circuit 2
2 constitutes the acquisition means of the present invention, and the edge emphasizing circuit 14, the CPU 10 and the like constitute the edge emphasizing means of the present invention.

In this configuration, the edge width (thickness) of the subject to be emphasized can be set to an appropriate width (thickness) for the captured image by appropriately setting the switching amount. The same effects as in the third embodiment can be obtained. Moreover, in the present embodiment, the switching of the edge width is performed based on the amount of the high frequency component of the spatial frequency in the image signal, that is, the information obtained directly from each of the captured images allows the captured image to be a fine image. Since it is determined whether the image is a coarse image or a coarse image, it can be accurately determined as compared with the case where the content of the subject is determined from the subject distance and the zoom magnification described in the first to third embodiments. Therefore, it is possible to further enhance the edge enhancement for each captured image.

This effect can be obtained by judging the contents of the subject from the amount of the high-frequency component of the spatial frequency in the image signal, as in the present embodiment, as in the first and second embodiments. It can also be obtained in a configuration in which the shading of the edge of the subject to be emphasized is changed. Further, filter switching and gain switching may be performed according to the amount of high frequency components. In the present embodiment and the third embodiment,
In the case of changing the edge width of the subject to be emphasized as in the embodiment, for example, in addition to the first and second edge extraction filters 15 and 16 described above, for example, the middle of the edge width extracted by them is used. By preparing another edge extraction filter for extracting the edge of the width and changing the edge width of the subject at another stage based on the amount of the high frequency component of the spatial frequency in the image signal, more appropriate edge enhancement is performed. Can be.

Further, in the present embodiment, the case where the edge enhancement is performed on the image signal obtained at the time of photographing has been described, but the image data having the information for judging the content of the subject is recorded in the memory 5 or the like. In such a case, the same effect as in the present embodiment can be obtained by performing the above-described edge enhancement processing on such image data. In this case, depending on whether or not the recorded image data has been subjected to the conventional edge emphasis processing, the degree of edge emphasis can be changed, or the degree of edge emphasis can be changed (the edge portion described above). Density or edge width)
, It is possible to perform more appropriate edge enhancement. Although the case where the subject distance is acquired by the distance sensor has been described, a configuration in which the subject distance is acquired by means other than the distance sensor, such as an AF lens position in a digital camera that performs contrast AF, may be used. Further, in the case of performing the edge enhancement processing according to the zoom magnification, the degree of edge enhancement may be changed depending on whether the zoom magnification is an electronic zoom magnification or a magnification when both optical zoom and electronic zoom are combined. Good. Also, the case where the present invention is applied to a digital camera has been described, but other than this, the present invention may be applied to other imaging devices that handle image information and other devices that process image information sent from the imaging device. it can. Even in such a case, image quality can be improved by performing edge enhancement suitable for the content of the subject.

[0030]

As described above, in the present invention,
Depending on the shooting distance information and the zoom magnification information, the density of the edge portion of the subject and the edge width are changed, and if there is a difference in the content of the subject such as a coarse image such as a portrait or a fine image such as a landscape photograph, Edge enhancement of the subject is performed with different degrees of enhancement according to the difference. Therefore, it is possible to perform edge enhancement suitable for the content of the subject. For example, in a digital camera,
A more natural image quality can be obtained irrespective of the content of the shooting target such as a portrait or a landscape photograph.

In particular, if edge enhancement of a subject is performed in accordance with both shooting distance information and zoom magnification information,
Since the content of the subject can be more accurately determined, the image quality is improved. Furthermore, if the edge enhancement of the subject is performed in accordance with the amount of the high frequency component of the spatial frequency in the image signal, the content of the subject can be determined very accurately, so that the image quality is further improved.

[0032]

[Brief description of the drawings]

FIG. 1 is a block diagram of a digital camera according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an edge emphasizing circuit according to the first embodiment of the present invention.

FIG. 3 is a waveform chart showing an operation of the edge enhancement circuit.

FIG. 4 is a flowchart illustrating a procedure of a gain adjustment process of a CPU.

FIG. 5 is an explanatory diagram showing an operation of an edge emphasizing circuit accompanying the gain adjustment processing.

FIG. 6 is a flowchart illustrating a second embodiment of the present invention and corresponding to FIG. 4;

FIG. 7 is an explanatory view corresponding to FIG. 5 in the embodiment.

FIG. 8 is an explanatory view corresponding to FIG. 7 showing another embodiment.

FIG. 9 is a block diagram illustrating an edge emphasizing circuit according to a third embodiment of the present invention.

FIGS. 10A and 10B are diagrams illustrating a function of a first edge extraction filter, where FIG. 10A illustrates an example of image data, and FIG. 10B illustrates an input signal and an output signal, respectively.

11A and 11B are diagrams illustrating a function of a second edge extraction filter, where FIG. 11A illustrates an example of image data, and FIG. 11B illustrates an input signal and an output signal, respectively.

FIG. 12 is a waveform chart showing an operation of the edge enhancement circuit.

FIG. 13 is a block diagram of a digital camera according to a third embodiment of the present invention.

FIG. 14 is a block diagram showing an edge emphasizing circuit according to the embodiment;

15A and 15B are characteristic diagrams of a spatial frequency in an output signal of a spatial frequency detection circuit, where FIG.
FIG. 4 is a diagram showing an example at the time of close-up shooting.

[Explanation of symbols]

 Reference Signs List 1 CCD 3 YUV conversion circuit 4 Edge enhancement circuit 6 Edge extraction filter 7 Coring circuit 8 Amplifier 9 Adder 10 CPU 11 Distance measurement sensor 12 ROM 14 Edge enhancement circuit 15 First edge extraction filter 16 Second edge extraction filter 21 Spatial frequency detection circuit 22 Full-wave rectifier circuit

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Akira Hamana 3-2-1, Sakaemachi, Hamura-shi, Tokyo Casio Computer Co., Ltd. Hamura Technical Center F-term (reference) 5C021 PA17 PA33 PA62 PA66 RA02 RB05 RB08 XB03 XB16 5C022 AA13 AB22 AB66 AC42 AC69

Claims (8)

[Claims] 1. An edge enhancement unit that enhances an edge of a subject with respect to an image signal generated by an imaging device that captures a subject image as image information by an imaging element; and an acquisition unit that acquires shooting distance information of the subject in the image signal. An edge enhancement device comprising: a control unit that changes a degree of edge enhancement by the edge enhancement unit in accordance with the photographing distance information acquired by the acquisition unit. 2. The image processing apparatus according to claim 1, wherein the acquiring unit acquires zoom magnification information in addition to the photographing distance information, and the control unit acquires the edge corresponding to the photographing distance information and the zoom magnification information acquired by the acquiring unit. 2. The edge emphasizing device according to claim 1, wherein a degree of emphasis of the edge by the emphasizing means is changed. 3. An edge emphasizing means for emphasizing an edge of a subject with respect to an image signal generated by an imaging device which captures a subject image as image information by an imaging element; an acquiring means for acquiring zoom magnification information of the subject; Control means for changing the degree of edge enhancement by the edge enhancement means in accordance with the zoom magnification information acquired by the means. 4. An edge enhancing means for enhancing an edge of a subject with respect to an image signal generated by an imaging device which captures a subject image as image information by an image sensor, and acquiring an amount of a high frequency component of a spatial frequency in the image signal. An edge emphasizing device, comprising: means for controlling the degree of edge emphasis by the edge emphasizing means in accordance with the amount of high-frequency components acquired by the acquiring means. 5. The edge emphasizing device according to claim 1, wherein said control means causes said edge emphasizing means to perform an emphasis process for changing luminance of an edge portion of said subject. 6. The edge emphasizing apparatus according to claim 1, wherein said control means causes said edge emphasizing means to change a width of an edge portion of said subject to be emphasized. . 7. The apparatus according to claim 6, further comprising a plurality of different edge extraction filters, wherein the control means changes the width of an edge portion of the subject to be emphasized by switching and selecting the edge extraction filters. An edge enhancement device as described. 8. An object edge enhancement method for an image signal generated by an imaging device that captures an object image as image information by an imaging element, wherein prior to edge enhancement of the object, it is determined whether the image is a fine image, An edge emphasizing method characterized by changing the degree of edge emphasis according to the result of the judgment.