JP2005033698A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus wherein influence in gamma control is suppressed as much as possible even in the case of an image pick-up signal whose frequency characteristic is deteriorated and high-definition profile correction is enabled. <P>SOLUTION: The imaging apparatus is provided with a first and a second profile signal creation circuits which create profile signals, a first and a second frequency and gain selecting circuits which select boost frequency and gain of output profile signals of the first and the second profile signal creation circuits, a first addition circuit which adds an output signal of the first frequency and gain selecting circuit and an image pick-up signal, a gamma control circuit which performs gamma control to an output signal of the first addition circuit, and a second addition circuit which adds the output signal of the gamma control circuit and the output signal of the second frequency and gain selecting circuit. Boost frequency characteristic of the first and the second profile signal creation circuits is made changeable, so that suppression of frequency degradation and profile correction for imaging are enabled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus provided with contour correction for improving the sharpness of an image and obtaining a high-quality imaging signal.

  There is a contour signal forming circuit as a circuit for performing processing for increasing the sharpness of an image and obtaining a high-quality image pickup signal. A signal obtained by this processing is called a detail signal, an aperture signal, or the like, and is indispensable to the imaging apparatus from the viewpoint of image creation.

  As a method for obtaining this contour signal, a method has been proposed in which a suitable contour signal can be added from the black level to the white level (see Patent Document 1).

  Hereinafter, a conventional imaging device including the contour signal forming circuit will be described.

  As an imaging device for obtaining a conventional high-quality imaging signal, for example, an imaging device described in Patent Document 1 is known. FIG. 12 shows an internal configuration of a contour signal forming circuit of a conventional imaging apparatus. In FIG. 12, 30 is an input terminal, 31 is a horizontal contour signal forming circuit, 32 is a vertical contour signal forming circuit, 33 is a first control circuit, 34 is a gamma correction circuit, 35 is a second control circuit, and 36 is an output. Terminal.

  The operation of the conventional image pickup apparatus configured as described above for obtaining a high-quality image pickup signal will be described below with reference to FIGS.

  FIG. 13 is a signal waveform diagram illustrating the contour correction operation, FIG. 14 is an input / output characteristic diagram illustrating gamma correction in the imaging apparatus and the monitor, and FIGS. 15 to 17 are signal waveform diagrams illustrating how the contour signal is attached in each method. It is.

  In FIG. 12, the horizontal contour signal forming circuit 31 and the vertical contour signal forming circuit 32 perform contour correction processing by forming a contour signal and adding it to the original input signal as shown in FIG. For example, when a window signal of a luminance signal is input as shown in FIG. 13A, high frequency components of the input signal are extracted to generate a contour signal shown in FIG. The signal is added to the input luminance signal, and a contour-corrected luminance signal shown in FIG.

  By the way, in general, in order to correct the gamma characteristic on the monitor side having the characteristics shown in FIG. 14B, the imaging apparatus performs gamma correction with the characteristics shown in FIG. In other words, the approximate black level side is expanded and the white level side is compressed. Therefore, since the characteristic of the contour correction changes depending on whether the previous contour correction is performed before or after the gamma processing, it affects the image creation.

  FIGS. 15A to 15C show signal waveform diagrams in the case where a contour correction signal is generated before gamma correction, contour correction is further performed, and gamma correction is performed. In this case, the contour-corrected input signal is added with the same contour signal regardless of the level of the input signal, as shown in FIG. Then, as shown in FIG. 5B, the dark part is expanded and the bright part is compressed. Therefore, even if reverse gamma correction is performed on the monitor side as shown in FIG. The contour signal becomes smaller and the balance of the contour signal becomes worse. FIGS. 16A to 16C show signal waveform diagrams when the contour correction signal is generated before gamma correction, and the contour correction is performed after the gamma correction. In this case, a contour signal of the same level is added to the input signal subjected to gamma correction, resulting in a signal waveform as shown in FIG. When this signal is subjected to inverse gamma correction on the monitor side, it becomes as shown in FIG. In this case, contrary to the case of FIG. 15, the level of the contour signal in the bright portion is larger than that in the dark portion, and the balance of the contour signal is also deteriorated. In order to solve such a problem, in the conventional imaging apparatus, the contour signal created by the horizontal contour signal forming circuit 31 and the vertical contour signal forming circuit 32 is set to an appropriate level by the first control circuit 33 shown in FIG. The gamma correction circuit 34 performs contour correction and gamma correction.

  Signal waveforms in this case are as shown in FIGS. 17 (a) and 17 (b). Further, the contour signal output from the first control circuit 33 is gain-controlled to a more appropriate level by the second control circuit 35 and added to the output signal of the gamma correction circuit 34. When this signal is subjected to inverse gamma correction by the monitor, a signal having a uniform level of the contour signal from the dark part to the bright part is obtained as shown in FIG.

In this way, by adding the contour signal before and after the gamma correction, a well-balanced contour correction can be performed, and a high-quality image signal can be provided.
Japanese Patent Laid-Open No. 9-247501, paragraph number “0012”

  However, in the above conventional imaging apparatus, a contour correction with a good balance can be performed by adding contour signals before and after the gamma correction, but the contour signals to be added basically have the same characteristics. Therefore, other problems caused by gamma correction, for example, by adding a contour signal to the waveform distortion due to frequency degradation that is emphasized by gamma correction, ideal contour correction cannot be performed, and there is a sense of incongruity. It had the problem of losing image quality.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an image pickup apparatus with high image quality that can perform ideal contour correction even in the case of an image signal whose frequency has deteriorated.

  In order to achieve this object, an imaging apparatus according to the present invention includes first and second contour signal generation circuits for generating a contour signal for performing contour correction from an imaging signal, and the first contour signal generation circuit. A first frequency / gain selection circuit for selecting a boost frequency and a gain of the output contour signal; and a second frequency / gain selection circuit for selecting a boost frequency and a gain of the output contour signal of the second contour signal generation circuit; A first addition circuit for adding the output signal of the first frequency / gain selection circuit and the imaging signal, a gamma correction circuit for performing gamma correction on the output signal of the first addition circuit, and the gamma correction circuit And a second addition circuit for adding the output signal of the second frequency and gain selection circuit.

  With this configuration, even in the case of an imaging signal whose frequency has deteriorated, the frequency deterioration can be corrected and ideal contour correction can be performed.

  The imaging apparatus of the present invention also includes first and second contour signal generation circuits for generating a contour signal for performing contour correction from the imaging signal, and a frequency for detecting frequency characteristics such as a step response of the imaging signal. A first frequency / gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the first contour signal generating circuit based on an output signal of the characteristic detecting circuit and the frequency characteristic detecting circuit; and the second contour signal generating A second frequency / gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the circuit; a first addition circuit for adding the output signal of the first frequency / gain selection circuit and the imaging signal; A gamma correction circuit for performing gamma correction on the output signal of the first adder circuit; a second for adding the output signal of the gamma correction circuit and the output signal of the second frequency / gain selection circuit; It has a configuration in which an adding circuit.

  According to this configuration, it is possible to correct the frequency deterioration and correct the ideal contour more accurately according to the degree of the frequency deterioration.

  As described above, according to the present invention, it is possible to provide an imaging apparatus capable of preventing image quality deterioration due to frequency deterioration and performing ideal contour correction and obtaining a high-quality image signal.

  Furthermore, it is possible to provide an imaging device that detects the frequency degradation and automatically corrects it with high accuracy, prevents image quality degradation due to frequency degradation and ideal contour correction, and obtains a high-quality imaging signal. .

  Further, it is possible to provide an image pickup apparatus that can prevent image quality deterioration accompanying frequency deterioration according to the degree of frequency deterioration due to the zoom ratio of the lens and can perform ideal contour correction and obtain a high-quality image signal.

  As described above, according to the present invention, it is possible to provide an imaging apparatus having the effects described above.

  According to the first aspect of the present invention, the first and second contour signal generating circuits for generating a contour signal for performing contour correction from the imaging signal, and the output contour of the first contour signal generating circuit A first frequency / gain selection circuit for selecting a boost frequency and a gain of a signal; a second frequency / gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the second contour signal creation circuit; A first addition circuit that adds the output signal of the first frequency / gain selection circuit and the imaging signal; a gamma correction circuit that applies gamma correction to the output signal of the first addition circuit; and an output of the gamma correction circuit And a second addition circuit for adding the output signal of the second frequency and gain selection circuit, and the first and second contour signal generation circuits each have a contour based on an input imaging signal. signal To create. The first and second boost frequency and gain selection circuits select the boost frequency and gain of the contour signal created by the first and second contour signal creation circuits, respectively. The first adder circuit adds the input imaging signal, the first boost frequency and the output signal of the gain selection circuit, and outputs the result to the gamma correction circuit. The gamma correction circuit performs gamma correction. The second adder circuit has an action of adding the output signal of the gamma correction circuit and the output signal of the second boost frequency and gain selection circuit.

  According to the second aspect of the present invention, first and second contour signal generating circuits for generating a contour signal for performing contour correction from an imaging signal, and a frequency for detecting frequency characteristics such as a step response of the imaging signal. A first frequency / gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the first contour signal generating circuit based on an output signal of the characteristic detecting circuit and the frequency characteristic detecting circuit; and the second contour signal generating A second frequency / gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the circuit; a first addition circuit for adding the output signal of the first frequency / gain selection circuit and the imaging signal; A gamma correction circuit for performing gamma correction on the output signal of the first adder circuit; and a second for adding the output signal of the gamma correction circuit and the output signal of the second frequency / gain selection circuit. It is those in which a calculation circuit, first, second contour signal generating circuit from the image pickup signal inputted, respectively to create a contour signal. The first boost frequency and gain selection circuit selects the boost frequency and gain of the contour signal created by the first contour signal creation circuit based on the output signal of the frequency characteristic detection circuit.

  The second boost frequency and gain selection circuit selects the boost frequency and gain of the contour signal created by the second contour signal creation circuit. The first adder circuit adds the input imaging signal and the output signal of the first boost frequency and gain selection circuit and outputs the result to the gamma correction circuit. The gamma correction circuit performs gamma correction. The second adder circuit has an action of adding the output signal of the gamma correction circuit and the output signal of the second boost frequency and gain selection circuit.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to Embodiment 1 of the present invention.

  In FIG. 1, 1 is a first contour signal forming circuit for forming a contour signal of an input signal, 2 is a second contour signal forming circuit for similarly forming a contour signal of an input signal, and 3 is a first boost frequency and gain selection circuit. Reference numeral 4 denotes a second boost frequency and gain selection circuit, 5 denotes a first addition circuit, 6 denotes a RAM table or a gamma correction circuit by broken line approximation, and 7 denotes a second addition circuit.

  The operation of the image pickup apparatus according to Embodiment 1 configured as described above will be described below with reference to FIGS.

  2 and 3 show signal waveform diagrams in the case of conventional contour correction and in the case of contour correction in the first embodiment, and show signal waveform diagrams of contour correction for an imaging signal whose frequency is deteriorated. (B)-(f) in a figure shows the signal waveform corresponding to each part (b)-(f) of FIG.

  FIG. 4 is a block diagram showing an example of the internal configuration of the first contour signal forming circuit 1 and the first boost frequency and gain selection circuit 3, and a frequency characteristic diagram showing characteristics of each boost frequency.

  FIG. 5 is a block diagram showing an example where the first contour signal forming circuit 1 and the first boost frequency and gain selection circuit 3 are integrated.

  An ideal imaging signal is a signal as shown in FIG. 2A for a window-shaped subject. This signal is subjected to signal processing such as gamma correction and contour correction, which are the main signal processing of the imaging apparatus. Actually, however, an imaging signal having a deteriorated frequency characteristic is input as shown in FIG. 4B due to deterioration of the analog frequency characteristic or the like.

  Correcting the deterioration of the frequency characteristic is one of the roles of contour correction, but actually it is mainly used to improve the sharpness for image creation. When the image signal with degraded frequency shown in FIG. 5B is input, the gamma correction circuit produces a signal with a particularly wide base as shown on the right side of FIG. 5B, and the contour shown in FIG. The signal is also a contour signal whose gain is increased on the negative side. That is, when the frequency-degraded imaging signal is subjected to contour correction and gamma correction, an imaging signal as shown in FIG. As can be seen from the figure, the rising and falling edges are not steep and gentle, and the image signal with a thin contour signal is provided where the base of the dark portion is widened. Further, when the output signal of the second contour signal generating circuit shown in FIG. 5 (e) is added to the signal, the level of the skirt of the dark part increases gently once, as shown in FIG. The tendency of falling to the negative side and rising of the waveform (reverse on the falling side) becomes stronger.

  This is because the conventional contour correction method basically adds contour signals having the same characteristics before and after the gamma correction.

  In the first embodiment, the boost frequencies of the first contour signal forming circuit 1 and the second contour signal forming circuit 2 are not made to have the same characteristic as in the prior art, and each has a plurality of boost frequencies. The second boost frequency and gain selection circuits 3 and 4 can be selected and gain set separately.

  FIG. 3 shows the state of the correction. In contrast to the imaging signal whose frequency is degraded in FIG. 3B, the imaging signal itself becomes a signal on the right side of FIG. Further, as shown in FIG. 6C, the contour signal output from the first contour signal forming circuit 1 is set to a first boost frequency and gain selection circuit with a low boost frequency according to the spread of the base as shown in FIG. Select with 3. That is, when this signal is added to the imaging signal whose frequency has been degraded by the first addition circuit 5 and gamma correction is performed by the gamma correction circuit 6, it is output as a signal close to an ideal imaging signal as shown in FIG. The On the other hand, the second boost frequency and gain selection circuit 4 selects a contour signal necessary for image creation from the contour signal output from the second contour signal forming circuit 2 and outputs the contour signal shown in FIG. The second adder circuit 7 adds this signal and the signal from the gamma correction circuit 6 to obtain an image pickup signal shown in FIG. Such contour correction can provide a high-quality image pickup signal.

  4 is a block diagram showing an example of the internal configuration of the first contour signal forming circuit 1 and the first boost frequency and gain selection circuit 3, and a frequency characteristic diagram showing characteristics of each boost frequency. A filter circuit, 9 is a selection circuit, and 10 is a multiplier. Each HPF 8 (high-pass filter circuit) outputs various boost frequencies, the signal is selected by a selection circuit 9 by an external boost frequency selection signal, a gain is set by a multiplier 10 and output. As an example of the characteristics of each HPF 8, frequency and characteristic diagrams are shown at the bottom of the figure. This frequency characteristic can be varied by an external characteristic variable signal. In this way, various boost frequencies and their gains can be set. The internal configurations of the second contour signal forming circuit 2 and the second boost frequency and gain selection circuit 4 are also the same.

  FIG. 5 is a block diagram showing an example in which the first contour signal forming circuit 1 and the first boost frequency and gain selection circuit 3 are integrated, but 11 is an integration of the boost frequency and gain selection circuit. The first contour signal forming circuit 12 is a delay element in digital processing (in the case of horizontal contour correction, one clock unit, in the case of vertical contour correction, one horizontal scanning unit), 13 and 15 are multipliers, and 14 is an adder. It is. By appropriately changing the coefficient setting of the multiplier 13 by an external coefficient switching signal, a contour signal having a boost frequency similar to the frequency characteristic diagram of FIG. 4 can be created.

  As described above, according to the first embodiment, the contour signal having the boost frequency suitable for correcting the frequency deterioration of the input imaging signal among the contour signals output from the first contour signal forming circuit 1 is the first. The contour signal selected by the boost frequency and gain selection circuit 3 and output from the second contour signal forming circuit 2 is basically selected by the second boost frequency and gain selection circuit 4 as a contour signal for image creation and imaged. Since it can be added to the signal, a high-quality image pickup signal can be provided.

(Embodiment 2)
FIG. 6 is a block diagram showing a configuration of the imaging apparatus according to Embodiment 2 of the present invention.

  In FIG. 6, 1 is a first contour signal forming circuit for forming a contour signal of an input signal, 2 is a second contour signal forming circuit for similarly forming a contour signal of an input signal, and 3 is a first boost frequency and gain selection circuit. 4 is a second boost frequency and gain selection circuit, 5 is a first addition circuit, 6 is a RAM table or a gamma correction circuit by broken line approximation, 7 is a second addition circuit, and 16 is a frequency for detecting each frequency component. It is a characteristic detection circuit. The difference from the first embodiment in FIG. 1 is that a frequency characteristic detection circuit 16 is provided. Others are similar circuits, and the description of the operation and action is omitted.

  The operation of the image pickup apparatus according to the second embodiment configured as described above will be described below with reference to FIGS.

  FIG. 7 is a block diagram showing the internal configuration of the frequency characteristic detection circuit 16. Reference numeral 17 denotes each frequency band component detection circuit for detecting each frequency band component of low frequency, intermediate frequency and high frequency, and 18 denotes the level of each frequency component. The level detection characteristic determination circuit determines the frequency characteristic of the input signal.

  In FIG. 7, each frequency band component detection circuit 17 extracts each frequency component of the input signal by a filter circuit such as a low-pass filter, a mid-pass filter, or a high-pass filter. In this case, when an image signal window signal or step signal (which may be a test signal) is input as an input signal, an ideal characteristic level of the input signal is prepared in advance, and the level and the actual input signal The level detection circuit 18 compares the level of each frequency component to determine which frequency component is degraded. Based on the determination signal, the boost frequency and gain of the first boost frequency and gain selection circuit 3 in FIG. 6 are selected. That is, by selecting a boost frequency having characteristics suitable for frequency degradation, the frequency characteristics are close to ideal. As a result, contour correction before gamma correction can be performed in substantially the same manner as in the first embodiment, and subsequent operations are also performed in the same manner as in the first embodiment, thereby preventing image quality degradation due to conventional frequency degradation. Can do. Moreover, the correction operation can be performed almost automatically.

  The ideal data of the frequency characteristics may be held as control data in a microcomputer for system control (not shown).

(Embodiment 3)
FIG. 8 is a block diagram showing a configuration of the imaging apparatus according to Embodiment 3 of the present invention.

  In FIG. 8, 1 is a first contour signal forming circuit for forming a contour signal of an input signal, 2 is a second contour signal forming circuit for similarly forming a contour signal of an input signal, and 3 is a first boost frequency and gain selection circuit. Reference numeral 4 denotes a second boost frequency and gain selection circuit, 5 denotes a first addition circuit, 6 denotes a RAM table or a gamma correction circuit by broken line approximation, 7 denotes a second addition circuit, and 19 denotes a frequency for detecting each frequency component. It is a characteristic detection circuit. 6 differs from the second embodiment in that the frequency characteristic detection circuit 19 detects the frequency characteristic using the output signal of the gamma correction circuit 6 as an input signal, and selects the first boost frequency and gain based on the detection signal. In this configuration, a control signal is output to the circuit 3. Others are similar circuits, and the description of the operation and action is omitted.

  The operation of the image pickup apparatus according to Embodiment 3 configured as described above will be described below with reference to FIGS.

  FIG. 9 is a block diagram showing the internal configuration of the frequency characteristic detection circuit 19, where 20 is a frequency band component detection circuit for detecting each frequency band component of low frequency, intermediate frequency, and high frequency, and 21 is a level detection for each frequency component. A level detection characteristic determination circuit 22 for determining the frequency characteristic of the input signal, and an error determination circuit 22 for determining an error from the ideal characteristic.

  In FIG. 9, each frequency band component detection circuit 20 extracts each frequency component of the input signal by a filter circuit such as a low-pass filter, a mid-pass filter, or a high-pass filter, for example, in the same manner as each frequency band component detection circuit 17 in FIG. To do. In this case, as the input signal, a window signal or a step signal (which may be a test signal) of the imaging signal is corrected once by the first contour signal forming circuit 1 and further subjected to gamma correction by the gamma correction circuit 6 as an input signal. Each frequency component is output. The level detection characteristic determination circuit 21 compares the level of the ideal characteristic of the input signal provided in advance with the level of each frequency component of the signal after the gamma correction circuit 6, and determines which frequency component is degraded. The boost frequency and gain of the first boost frequency and gain selection circuit 3 in FIG. 8 are selected by the determination signal. Further, the level of the frequency determined to have frequency degradation (determination frequency level) is output to the error determination circuit 22. The error determination circuit 22 compares the determination frequency level with the level reference signal of ideal characteristics, and outputs an error signal indicating how much error there is. This error signal is detected by a microcomputer, not shown. By turning the feedback loop so as to adjust the first boost frequency and the gain of the gain selection circuit 3 so that the error signal is below a certain level, the frequency characteristic is ideal for the signal after gamma correction. It can be close to frequency characteristics.

  As described above, according to the third embodiment, based on the frequency characteristic of the signal after the gamma correction in which the deterioration of the frequency characteristic is emphasized, the characteristic can be brought close to the ideal frequency characteristic with considerably high accuracy. Since correction is performed, it is possible to prevent image quality deterioration due to conventional frequency deterioration. Moreover, the correction operation can be performed almost automatically.

  The ideal data of the frequency characteristics may be held as control data in a microcomputer for system control, not shown, as in the case of the second embodiment.

(Embodiment 4)
FIG. 10 is a block diagram showing the configuration of the imaging apparatus according to Embodiment 4 of the present invention.

  In FIG. 10, 1 is a first contour signal forming circuit for forming a contour signal of an input signal, 2 is also a second contour signal forming circuit for similarly forming a contour signal of an input signal, and 3 is a first boost frequency and gain selection circuit. 4 is a second boost frequency and gain selection circuit, 5 is a first addition circuit, 6 is a RAM table or a gamma correction circuit by broken line approximation, 7 is a second addition circuit, and 16 is a frequency for detecting each frequency component. It is a characteristic detection circuit. 6 differs from the second embodiment in that the first boost frequency and gain selection circuit 3 is controlled not only by the frequency characteristic detection circuit 16 but also by a zoom ratio signal of the lens. Others are similar circuits, and the description of the operation and action is omitted.

  The operation of the image pickup apparatus according to Embodiment 4 configured as described above will be described below with reference to FIGS.

  FIG. 11 is a conceptual diagram showing how the first boost frequency and the gain selection circuit 3 select the boost frequency. The frequency selected by the frequency characteristic detection circuit 16 to correct the characteristic deterioration is set as the center frequency. In this case, the boost frequency of the first contour signal is increased as the zoom ratio signal of the lens becomes a signal indicating the tele end. Switch to a lower frequency. Conversely, the signal is switched to a higher frequency as the signal indicates the wide end. In this way, especially in a step-like or window-like subject whose frequency degradation is easy to understand, the frequency component of the subject changes with the zoom ratio of the lens. Can be prevented.

  Needless to say, the above control can be easily performed by a microcomputer (not shown).

1 is a block diagram illustrating a configuration of an imaging apparatus according to Embodiment 1 of the present invention. Signal waveform diagram of each part for explanation of operation of imaging device in embodiment 1 Signal waveform diagram of each part for explanation of operation of imaging device in embodiment 1 Block diagram and boost frequency characteristic diagram showing the internal configuration of the first contour signal forming circuit 1 and the first boost frequency and gain selection circuit 3 in the first embodiment The block diagram which shows an example of an internal structure when the 1st outline signal formation circuit 1 and the 1st boost frequency and gain selection circuit 3 in the same Embodiment 1 are integrated. FIG. 3 is a block diagram illustrating a configuration of an imaging apparatus according to Embodiment 2 of the present invention. The block diagram which shows an example of the internal structure of the frequency characteristic detection circuit 16 in the Embodiment 2 FIG. 5 is a block diagram illustrating a configuration of an imaging apparatus according to Embodiment 3 of the present invention. The block diagram which shows an example of the internal structure of the frequency characteristic detection circuit 19 in the Embodiment 3 FIG. 6 is a block diagram illustrating a configuration of an imaging apparatus according to Embodiment 4 of the present invention. The conceptual diagram which shows the selection method of the boost frequency of the 1st boost frequency and the gain selection circuit 3 in Embodiment 4 Block diagram showing the configuration of a conventional imaging device Signal waveform diagram showing contour correction operation of a conventional imaging device I / O characteristics diagram showing gamma correction in imaging device and monitor Signal waveform diagram showing how to add contour signal in each method in contour correction of conventional imaging device Signal waveform diagram showing how to add contour signal in each method in contour correction of conventional imaging device Signal waveform diagram showing how to add contour signal in each method in contour correction of conventional imaging device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st outline signal formation circuit 2 2nd outline signal formation circuit 3 1st boost frequency and gain selection circuit 4 2nd boost frequency and gain selection circuit 5 1st addition circuit 6 Gamma correction circuit 7 2nd addition circuit 8 High pass filter circuit DESCRIPTION OF SYMBOLS 9 Selection circuit 10 Multiplier 11 Boost frequency and gain selection circuit integrated structure 1st outline signal formation circuit 12 Delay element in digital processing 13, 15 Multiplier 14 Adder 16, 19 Frequency characteristic detection circuit 17, 20 Each frequency band component detection Circuits 18, 21 Level detection characteristic determination circuit 22 Error determination circuit

Claims (5)

First and second contour signal generation circuits for generating a contour signal for performing contour correction from the imaging signal;
A first frequency and gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the first contour signal generation circuit;
A second frequency and gain selection circuit for selecting a boost frequency and a gain of the output contour signal of the second contour signal generation circuit;
A first addition circuit for adding the output signal of the first frequency and gain selection circuit and the imaging signal;
A gamma correction circuit for performing gamma correction on the output signal of the first addition circuit;
An imaging apparatus comprising: an output signal of the gamma correction circuit; and a second addition circuit for adding the output signal of the second frequency and gain selection circuit. First and second contour signal generation circuits for generating a contour signal for performing contour correction from the imaging signal;
A frequency characteristic detection circuit for detecting a frequency characteristic such as a step response of the imaging signal and a boost frequency and a gain of an output contour signal of the first contour signal generation circuit are selected based on an output signal of the frequency characteristic detection circuit. Frequency and gain selection circuit;
A second frequency and gain selection circuit for selecting a boost frequency and a gain of the output contour signal of the second contour signal generation circuit;
A first addition circuit for adding the output signal of the first frequency and gain selection circuit and the imaging signal;
A gamma correction circuit for performing gamma correction on the output signal of the first addition circuit;
An imaging apparatus comprising: an output signal of the gamma correction circuit; and a second addition circuit for adding the output signal of the second frequency and gain selection circuit. First and second contour signal generation circuits for generating a contour signal for performing contour correction from the imaging signal;
A boost characteristic and a gain of an output contour signal of the first contour signal generation circuit are determined by a frequency characteristic detection circuit for detecting a frequency characteristic such as a step response of the imaging signal, an output signal of the frequency characteristic detection circuit, and a zoom ratio of the lens. A first frequency and gain selection circuit to select;
A second frequency and gain selection circuit for selecting a boost frequency and a gain of the output contour signal of the second contour signal generation circuit;
A first addition circuit for adding the output signal of the first frequency and gain selection circuit and the imaging signal;
A gamma correction circuit for performing gamma correction on the output signal of the first addition circuit;
An imaging apparatus comprising: an output signal of the gamma correction circuit; and a second addition circuit for adding the output signal of the second frequency and gain selection circuit. When the zoom ratio of the lens is close to the wide side from the middle between the tele end and the wide end, the setting of the first frequency and gain selection circuit is selected, and a higher frequency is selected, and the middle between the tele end and the wide end is selected. 4. The image pickup apparatus according to claim 3, wherein when the distance is close to the telephoto side, the first frequency and gain selection circuit is set so that a lower frequency is selected. 5. First and second contour signal generation circuits for generating a contour signal for performing contour correction from the imaging signal;
A first frequency and gain selection circuit for selecting a boost frequency and a gain of an output contour signal of the first contour signal generation circuit;
A second frequency and gain selection circuit for selecting a boost frequency and a gain of the output contour signal of the second contour signal generation circuit;
A first addition circuit for adding the output signal of the first frequency and gain selection circuit and the imaging signal;
A gamma correction circuit for performing gamma correction on the output signal of the first addition circuit;
A frequency characteristic detection circuit for detecting a frequency characteristic such as a step response of the output signal of the gamma correction circuit;
A control circuit for determining a frequency characteristic of an output signal of the frequency characteristic detection circuit and controlling frequency selection and gain of the first frequency and gain selection circuit;
An imaging apparatus comprising: an output signal of the gamma correction circuit; and a second addition circuit for adding the output signal of the second frequency and gain selection circuit.

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