Abstract: A pixel selection unit sets an area based on a detection result of a contrast detection unit, in a case where it is determined that reliability of a focusing state detected by a phase difference detection unit is low.

Abstract: A digital camera has an optical system, an image capturing unit, an aperture adjuster, a focal point adjuster, and a body microcomputer. The aperture adjuster has an aperture included in the optical system and is capable of adjusting the state of the aperture. The focal point adjuster has a focus lens included in the optical system and is capable adjusting the focal state of the optical system by using the focus lens by contrast detection method. The body microcomputer controls the operation of the aperture adjuster so that the aperture value of the optical system will be at or below a set aperture value before the focal state is adjusted by the focal point adjuster.

Abstract: Disclosed is a method for auto-focus control of a digital camera, the method including moving a focus lens of the digital camera to a position for a longest-distance photographing, and then extracting an edge value according to a corresponding position while moving the focus lens by a preset interval in a direction toward an image sensor; estimating a form of a preset function based on the extracted edge values, and calculating a maximum value of the estimated function; calculating a difference between a maximum value of the preset function calculated at a first current position of the focus lens and a maximum value of the preset function calculated at a previous position of the focus lens; and moving the focus lens to a position corresponding to a currently-calculated maximum value of the preset function when the difference between the maximum value of the preset function calculated at the first current position of the focus lens and the maximum value of the preset function calculated at the previous positio

Abstract: The present invention provides a photographing apparatus, in which an object image is formed on an image pickup element through a photographing lens, and a desired frequency component is extracted from an image signal obtained by the image pickup element through a filter so that the extracted frequency component is integrated to calculate a focus evaluation value and, based on the calculated focus evaluation value, an in-focus position of the photographing lens is searched, the apparatus comprising: a scene discrimination section which discriminates a photographing scene of an object image; and a control section which changes either of a searching range of the in-focus position of the photographing lens or the frequency component to be extracted by the filter based on the photographing scene discriminated by the scene discrimination section, and thereafter moves the photographing lens to search an in-focus position.

Abstract: A continuous focusing method for a digital camera is described, which is applicable to determine whether the digital camera performs a focusing procedure or not when the digital camera switches from a first scene to a second scene in a live view stage. The continuous focusing method includes the following steps. A preview image of a second scene is obtained. A blur detection procedure is performed on the preview image, so as to acquire a corresponding focus value. It is determined whether the focus value exceeds a focusing threshold value or not; if not, a focusing procedure is performed; otherwise, if the focus value is greater than the focusing threshold value, the digital camera still maintains a current focusing focal length, which represents that a focusing focal length of the second scene is the same as that of the first scene.

Abstract: A control method of detecting an object image to be focused from a sensed image, setting a focus detection area in detecting an in-focus state of a photographing optical system, and exercising control such that the photographing optical system is moved based on a signal output in the focus detection area to carry out focus control, wherein, in the setting of the focus detection area, a first focus detection area corresponding to an object to be focused detected from the sensed image and a second focus detection area which is larger than the first focus detection area are set, and in the focus control, control is exercised such that the photographing optical system is moved based on output signals in the set first and second focus detection areas.

Abstract: An image capturing apparatus performs autofocus control that uses a face detection function. The image capturing apparatus sets a face region as an AF frame if face detection is successful. However, if a state in which face detection is successful transitions to a state in which face detection has failed, and furthermore a variation between subject distances is less than or equal to a threshold value, the image capturing apparatus maintains the previous AF frame setting instead of changing the AF frame setting. If the variation in subject distances is greater than the threshold value, the image capturing apparatus sets the AF frame to a predetermined region that does not follow a face region.

Abstract: An image pickup apparatus includes an image pickup device that includes a plurality of focus detection pixels, a phase difference detection type of a first focus detector, a contrast detection type of a second focus detector, and a controller. The controller is configured to allow the second focus detector to continue the focus detection when the shift amount detected by the first focus detector is larger than a threshold even when the second focus detector detects the lens position corresponding to the peak of the contrast value, and to move the image pickup lens to a lens position that provides a peak of a contrast value detected by the second focus detector when the shift amount is the threshold or smaller.

Abstract: A fast focusing method for a digital camera is applied in an auto focusing stage for judging whether the digital camera needs to be refocused. The fast focusing method includes recording a system time after a previous focusing (defined as a first time); capturing a system time before a current focusing (defined as a second time); performing a fuzziness detection procedure to acquire a focus value when a difference obtained by subtracting the first time from the second time is greater than a focusing time threshold; setting a focusing focal length range covering a reference focal length when the focus value is between a lower limit focusing threshold and an upper limit focusing threshold; capturing images at different focusing focal lengths respectively in the focusing focal length range; calculating a contrast value of each image; calculating a target focal length from the contrast values through a quadratic curve approximation method.

Abstract: A camera system includes an interchangeable lens and a camera body. The interchangeable lens has a focal adjuster including a focus lens group, an absolute position detector configured to detect the position of the focus lens group with respect to a movable range, and a relative position detector configured to detect the movement amount of the focus lens group. The camera body has a first focal detector configured to detect the focal state on the basis of a contrast value and a second focal detector configured to detect the focal state by phase difference detection method on the basis of the optical image. When the first focal detector is used for focal adjustment, a detection of the focal state is performed on the basis of only the information obtained by the relative position detector.

Abstract: A digital camera includes: an imaging unit that receives and images a light from a subject transmitted a photographing optical system; a recognition unit that recognizes a feature region of the subject using an image obtained by imaging with the imaging unit; a detection unit that detects a size of the feature region that is recognized with the recognition unit; and a control unit that predicts a distance to the subject after a predetermined period of time according to the size of the feature region, and controls the photographing optical system so as to focus on the subject.

Abstract: An imaging apparatus includes a focus control unit that sets an image area including eyes, which is included in an input image inputted in the imaging apparatus, as a range finding area for calculation of a subject distance and acquires an evaluation value based on contrast of the range finding area to detect a focus position and a blink detecting unit that detects presence or absence of a blink on the basis of image analysis in the range finding area. The focus control unit inputs blink detection information in the blink detection unit, identifies evaluation value data in a blink period and a non-blink period, and executes processing for detecting a focus position on the basis of only an evaluation value in a period judged as the non-blink period.

Abstract: An imaging apparatus includes: an imaging optical system including a focus lens; an imaging element generates an image indicating an object image; a lens drive device which moves the focus lens along an optical axis direction of the imaging optical system; an evaluation value calculation device which calculates an evaluation value of a contrast for each of a plurality of evaluation value calculation areas while moving the focus lens; a point light source presence/absence determination device which determines a presence or absence of a point light source in a specific region of the image; an area selection device which selects a focusing determination area based on the presence or absence of the point light source; and a focusing control device which determines the focusing position of the focus lens based on the evaluation value in the focusing determination area and moves the focus lens to the focusing position.

Abstract: An electronic camera includes an image sensor. The image sensor has an imaging surface irradiated with an optical image of an object scene through a focus lens and repeatedly generates an object scene image. A CPU executes an AF process for adjusting a distance from the focus lens to the imaging surface to a distance corresponding to a focal point, based on the object scene image generated by the image sensor. However, the CPU has a high-luminance excluding function for excluding from a target to be noticed of the AF process a partial image having a luminance exceeding “TH1” out of the object scene image generated by the image sensor. The CPU determines whether or not a partial image having a luminance exceeding “TH2” larger than “TH1” exists on the object scene image generated by the image sensor, and turns on the high-luminance excluding function when a determination result is affirmative and turns off the high-luminance excluding function when the determination result is negative.

Abstract: An image-pickup apparatus is disclosed which is capable of realizing a focus-effect function in a constant time without being influenced by contrast of an object or the position of a focus lens. The apparatus includes a signal generator which generates a focus evaluation signal, a detector which detects information corresponding to an object distance, and a controller which performs focus lens control on the basis of the focus evaluation signal and focus lens control on the basis of information corresponding to the object distance. The controller determines a direction and a velocity in which the focus lens is moved toward an in-focus position on the basis of the information corresponding to the object distance in the focus lens control according to the focus-effect function. The controller performs the focus lens control on the basis of the focus evaluation signal after the focus lens is moved in the determined direction.

Abstract: A photographic device using a focus method includes a zoom lens, an image analyzing module, a focus distance providing module and a processing module. The zoom lens is used for capturing image information of a plurality of positions. The image analyzing module is used for analyzing contrast values of the image information of the plurality of positions. The focus distance providing module is used for providing a non-equivalent and a constant focus distance interval for capturing the image information of the plurality of positions. The processing module is electrically connected with the zoom lens, the image analyzing module, and the focus distance providing module. Whereby, the photographic device acquires the image information of the plurality of positions by the non-equivalent focus distance interval, acquires a coarse focus position, and acquires an accurate focus position by the constant focus distance according to the coarse focus position.

Abstract: An apparatus and method are disclosed wherein a depth map is generated using a single camera (e.g., single lens of a camera) and multiple images are captured by the camera. In some embodiments, a single digital camera is used to capture a set of images corresponding to a set of lens positions based on uniform or nonuniform lens position data. The method and apparatus determines focus metric information for each of a plurality of regions of interest in each image of a set. A determination is made of a best lens position for each of the regions of interest based on the focus metric information from the images in the set and are stored as data in a depth map. Image generation operations are then performed based on the generated depth map.

Abstract: Methods and systems for adjusting a video imaging system that includes an auto-focus mechanism wherein an input from a user of the video imaging system invokes an auto-focus procedure. Responsive to the input, the auto-focus mechanism is scanned over a range of focal distance from a first setting to a second setting indicated by the input. A sequence of images using the video imaging system is captured while scanning the auto-focus mechanism over the range. The images in the sequence are processed so as to compute a measure of focal quality with respect to each of the images. The measure of the focal quality is analyzed so as to select an optimal focal distance, and the auto-focus mechanism is set to the selected focal distance.

Abstract: A digital camera of the present invention enables a lens unit to be attachable/detachable with respect thereto. The digital camera of the present invention includes a plurality of display portions, a control portion that causes the plurality of display portions to selectively display the image data generated by the image pickup element or image data obtained by subjecting the image data generated by the image pickup element to predetermined processing as a moving image in real time, and a setting portion capable of switching displays of images with respect to the plurality of display portions. After the control portion causes the lens unit to perform an autofocus operation in accordance with setting of the displays of the images with respect to the plurality of display portions by the setting portion, the control portion switches the displays of the images with respect to the plurality of display portions.

Abstract: Descriptions are provided of various implementations of an automated tuning process configured to optimize a procedure for post-processing images captured by a camera sensor.

Abstract: A focus detection device includes: a light-receiving unit that receives a pair of images and outputs a first signal string and a second signal string; a decision-making unit that determines a condition assumed as the light-receiving unit receives the pair of images; a selection unit that selects a correlation operation expression among a plurality of correlation operation expressions in correspondence to the condition; a correlation calculation unit that calculates a correlation quantity between a plurality of first/second signals included in the first/second signal string by applying the correlation operation expression selected; a shift amount detection unit that detects a shift amount between the pair of images; and a focus detection unit that detects a focusing condition. The selection unit selects the correlation operation expression to reduce an extent to which signal intensity difference between the first and the second signal strings affects the correlation quantity.

Abstract: An imaging apparatus includes an image pickup device that includes a first pixel group configured to photoelectrically convert an object image formed by a luminous flux from an imaging optical system, and a second pixel group which includes a plurality of pixels configured to photoelectrically convert a split pair of the luminous flux from the imaging optical system and a detecting unit configured to implement a first detection control that changes an imaging state of the image pickup device while detecting a contrast of the object image based on an output of the second pixel group, and then a second detection control that changes the imaging state of the image pickup device while detecting the contrast of the object image based on an output of the first pixel group.

Abstract: Photographing apparatus and method to reduce auto-focus time are disclosed. A photographing apparatus is provided that includes two imaging optical systems; an imaging device that converts images of subjects formed by the imaging optical systems into respective image signals; a subject distance calculation unit that calculates subject distances between the imaging device and the subject based on two images generated by the imaging device; and an in-focus position detection unit that detects an in-focus position based on contrast evaluation values of the image signals obtained for a plurality of focusing positions, performs preparatory focusing driving by moving the focusing positions close to the in-focus position based on the calculated subject distances, and scans the focusing positions from the position close to the in-focus position to the in-focus position.

Abstract: An image pickup apparatus includes: an in-focus operation section configured to drive a focus lens to move over a predetermined driving range in order to detect evaluation values each representing the strength of the contrast of an image signal generated based on a subject of an image pickup operation from a plurality of predetermined positions and find an in-focus position of the focus lens based on the evaluation values; a detector configured to acquire first evaluation values obtained for the predetermined positions during a first period of driving the focus lens to move over the predetermined driving range, and second evaluation values obtained for at least one of the predetermined positions during a second period between the end of the first period and a process to find the in-focus position based on the first evaluation values; and a change measurement section configured to measure a change of the evaluation value.

Abstract: An imaging apparatus includes an imaging device receiving light from an object through an imaging lens at a predetermined imaging plane and performing photoelectric conversion of an object image to generate a captured image; a phase-difference detector for receiving the light from the object and generating a phase-difference detection signal corresponding to a focus level of the object image; an evaluation-value calculator for calculating a predetermined evaluation value corresponding to a contrast of the object image on the basis of the captured image; and a determining unit for selecting an optimum AF method from among a plurality of AF methods in which the phase-difference detection signal obtained by the phase-difference detecting unit and the predetermined evaluation value based on the captured image are used selectively or in combination, the optimum AF method being selected in accordance with image-capturing conditions of the object.

Abstract: Apparatus and method for electronically estimating focusing distance between a camera (still and/or video camera) and a subject. Images at different focal positions of a calibration target are collected with distances between subject positions. In one aspect, histogram matching is performed to reduce noise error. A focus matching model is then generated in response to detected blur differences between successive images of the calibration target. The focus matching model is preferably converted to a polynomial equation of a desired order to smooth out image collection noise. The focus matching model is stored for access during operation. In use, the distance to subject is estimated in response to capturing images, detecting blur differences between the images and entering the blur difference information into the matching model.

Abstract: An image pickup apparatus includes an extraction unit configured to extract feature points of an object from picked-up image data, a focus adjustment unit configured to, before starting pickup of an image for recording and/or storage, detect an in-focus position by moving a focus lens in a direction of an optical axis over a scan region which is decided based on the extracted feature points, and to control movement of the focus lens to be matched with the in-focus position, and an operation timing control unit configured to operate the focus adjustment unit and the extraction unit in a synchronous relation (inter-shooting AF(1) and AF(2)) in a continuous shooting mode in which the pickup of an image for recording and/or storage is repeated plural times.

Abstract: A digital camera has an optical system, an image capturing unit, an aperture adjuster, a focal point adjuster, and a body microcomputer. The aperture adjuster has an aperture included in the optical system and is capable of adjusting the state of the aperture. The focal point adjuster has a focus lens included in the optical system and is capable adjusting the focal state of the optical system by using the focus lens by contrast detection method. The body microcomputer controls the operation of the aperture adjuster so that the aperture value of the optical system will be at or below a set aperture value before the focal state is adjusted by the focal point adjuster.

Abstract: An imaging apparatus includes an optical system, a first focusing section that controls a focus of the optical system, and performs a first focusing process based on a first evaluation value, a second focusing section that controls the focus of the optical system, and performs a second focusing process based on a second evaluation value, and a focusing process switch section that switches a focusing process between the first focusing process and the second focusing process. The first focusing section includes an in-focus determination section that determines whether or not the first focusing process has been accomplished. The focusing process switch section switches the focusing process from the first focusing process to the second focusing process when the in-focus determination section has determined that the first focusing process has been accomplished.

Abstract: An auto-focus method for camera is provided. First, a digital signal processor sets a first parameter p and a second parameter q. An image capture unit captures an only image. Then, the digital signal processor utilizes the only image, the first parameter p and the second parameter q to compute an object distance. Then, an optical focusing device utilizes the object distance to regulate a focal position. Therefore, the present invention substantially shortens the time for regulating the focal position.

Abstract: Even when a point light source is present in a subject or a normal subject is erroneously determined as a point light source in determination of the presence or absence of a point light source, the following is implemented: the driving time of a focus lens is shortened and quick focusing operation is provided. The optimum focus lens stroke is computed based on information on a high-brightness region and a low-brightness region in an image. Then the focus lens is driven while the focus lens stroke is continuously varied based on the amount of change in high-brightness region and low-brightness region.

Abstract: The ratio between an image A and an image B is calculated as the comparison result of the images A and B obtained from a pair of optical images. The variance is then calculated in order to evaluate the statistical fluctuation of the ratio obtained for each pixel. The fluctuation due to the variance is evaluated for each phase difference while the phase between the image A and the image B is shifted. The phase difference detection is performed on the basis of the evaluation result of the fluctuation.

Abstract: An image pickup optical system including: a first prism including: a first incident surface where subject beam enters; a division surface for dividing the beam from the first incident surface into image-pickup beam and focus-detection beam; and a first exit surface from which reflection beam reflected on the division surface, the image-pickup beam or the focus-detection beam, exits; and a second prism including: a second incident surface on which transmission beam passing through the division surface, the image-pickup beam or focus-detection beam, enters; and a second exit surface from which the transmission beam exits, wherein the reflection beam is reflected on the division surface, reflected on the first incident surface, and reflected on the division surface to reach the first exit surface, and satisfying 0.1<DA/DB<0.5, where DA and DB indicate beam diameters of beams toward the image pickup elements for focus detection and for image pickup.

Abstract: A digital camera has an optical system, an image capturing unit, an aperture adjuster, a focal point adjuster, and a body microcomputer. The aperture adjuster has an aperture included in the optical system and is capable of adjusting the state of the aperture. The focal point adjuster has a focus lens included in the optical system and is capable adjusting the focal state of the optical system by using the focus lens by contrast detection method. The body microcomputer controls the operation of the aperture adjuster so that the aperture value of the optical system will be at or below a set aperture value before the focal state is adjusted by the focal point adjuster.

Abstract: A focusing method, suitable for an image capturing apparatus using in an environment of low brightness, is provided herein. The focusing method includes that an image sensing unit in the image capturing apparatus is wholly or partially divided into a plurality of regions, and digital image data sensed by the image sensing unit is divided into a plurality of sets corresponding to the regions of the image sensing unit. The regional image data corresponding to each of the regions are summed up during the focusing step, so as to obtain a sum of data for each region. Each sum of data is used to calculate a corresponding contrast value, and the contrast value is used to perform calculations for the focusing step, so as to obtain a focus.

Abstract: A focus control apparatus and method capable of shortening a focus adjustment time in focus control. The method includes extracting a first high frequency component depending upon a first cutoff frequency and a second high frequency component depending upon a second cutoff frequency higher than the first cutoff frequency from a video signal, generating first and second contrast signals of the video signal respectively based on the first and second high frequency components, using a quotient obtained by dividing a value of the first contrast signal by that of the second contrast signal as a parameter, exercising focus control based on the parameter, and setting the first and second cutoff frequencies so as to cause a value of the parameter to assume a peak when a focus lens in an image pickup apparatus is located in a position at a predetermined distance from an in-focus position.

Abstract: A method and system for low-complexity Slepian-Wolf rate estimator in a hybrid Wyner-Ziv video encoder determines the minimum Slepian-Wolf code rate required to allow correct decoding. The Slepian-Wolf estimator does not assume ideality of source and side-information statistics and does not require the presence of a feedback channel from the decoder to the encoder in order to determine the correct Slepian-Wolf coding rate. Instead, it adapts to the statistical properties of the video steam. The Slepian-Wolf estimator provides very efficient compression performance while avoiding Slepian-Wolf decoding failures.

Abstract: A focus adjustment apparatus including a face detector for detecting a person's face included in an image obtained by photographing, an eye detector for detecting an eye of the person included in the image, an evaluation value calculator for calculating an evaluation value representing the depth of field at the position of the detected face, and a focus adjuster for selectively performing the following based on the evaluation value: (a) performing focus adjustment to bring at least the detected face into focus, and (b) causing the eye detector to detect an eye of the person and performing focus adjustment to bring the detected eye into focus.

Abstract: In a case in which flickers are detected from a live-view image, at least one of a start timing and an end timing of charge accumulation at an image sensor is fixed by setting the image-sensing frame rate during execution of image-sensing plane AF to a value synchronized with the flicker cycle. In an image sensing apparatus for carrying out image-sensing plane AF with the use of live-view images, aperture control and accumulation time control with a high degree of freedom can be achieved even under a flicking light source.

Abstract: Provided is a zoom lens system including a compact focusing lens unit and having a suppressed change in image magnification at the time of movement of the focusing lens unit. A zoom lens system of the present invention, in order from an object side to an image side, includes, a first lens unit G1 having negative optical power, a second lens unit G2 having positive optical power, a third lens unit G3 having positive optical power, and a fourth lens G4. Condition (10): 1.4<DL/YM<2.5 and condition (11): 1.2<BFW/YM<1.6 are satisfied (where, 100<2?W<140, DL is an effective diameter of the lens surface closest to the image side, BFW is the back focus at a wide-angle limit, YM is the maximum image height at a wide-angle limit, and ?W is a half view angle (°) at a wide-angle limit).

Abstract: An electronic still camera includes a finder optical system for viewing a subject image. An imaging section obtains the subject image. A display section displays the subject image based on image data associated with the subject image obtained by the imaging section. A mode selecting section selects either a first mode in which the electronic still camera performs imaging operation using the imaging section while a user views the subject image through the finder optical system or a second mode in which the electronic still camera performs imaging operation using the imaging section while the user views the subject image on the display section. A first focus detection circuit performs a first focus detecting operation when the first mode is selected by the mode selecting section. A second focus detection circuit performs a second focus detecting operation when the second mode is selected by the mode selecting section.

Abstract: A data processing device includes: a face-detecting unit to detect a face region from an input image input from an imaging unit which images a subject including a face; a setting unit to calculate subject distance based on the face size of the face detected by the face-detecting unit, and set limits as a focus lens operation range before and after a focus lens position with the calculated subject distance as focal distance; a detecting unit to move a focus lens within the limits set by the setting unit, and detect a focal point where a detection value corresponding to the contrast intensity obtained from a face frame including the face detected by the face-detecting unit is not smaller than a threshold; and a control unit to determine, in a case wherein a focal point has been detected within predetermined set time, the focal point thereof as a focus position.

Abstract: In a digital video camera according to one aspect of the invention, a black level of a video signal is specified during an initialization process. An autofocusing process obtains an AF evaluation value and a brightness evaluation value at each current position of a compensator lens and updates a maximum AF evaluation value and a corresponding position of the compensator lens based on the obtained data. The autofocusing process also detects an AGC gain, computes an offset value of the AF evaluation value from the detected AGC gain, the obtained brightness evaluation value, and the specified black level, and calculates a threshold value from the computed offset value and the updated maximum AF evaluation value. When the obtained AF evaluation value is less than the calculated threshold value, the lens position corresponding to the maximum AF evaluation value is specified as the focus position.

Abstract: In a multi-focus camera apparatus that photographs the same region with cameras having different focal lengths, detection means for detecting a specified target in images obtained by the cameras, region acquisition means for obtaining in the images regions comprising pixels having substantially the same relationships between blurriness degrees as relationships between blurriness degrees of the specified target having been detected in the respective images, and image processing means for carrying out image processing to display the obtained regions differently from other regions are included.

Abstract: The present invention provides an image capture device that can cut down power dissipation and reduce noise at the same time. The image capture device includes: an imager; at least one lens for producing a subject image on the imager; an actuator for driving the at least one lens in accordance with a control signal; and a driver for outputting the control signal. The driver changes, according to a condition of a subject being shot, the control signals to output from an analog control signal into a digital control signal, or vice versa.

Abstract: An imaging apparatus comprises a focusing unit configured to focus an object to be shot by an imaging unit, a first shooting control unit configured to control the imaging unit in order to continuously shooting at first time intervals upon detecting a shooting instruction, a determining unit configured to determine whether the object moves in a distance direction during a control operation of the first shooting control unit, and a second shooting control unit configured to control the imaging unit in order to continuously shoot at second time intervals and to control the focusing unit in order to focus the object when the determining unit determines that the object moves in the distance direction.

Abstract: An auto-focusing apparatus and an image pickup apparatus reliably achieving a focal state in accordance with a recording format are provided. In each apparatus, auto-focus adjustment is implemented by modifying a process of generating an AF evaluation value indicating a sharpness of an image, in accordance with an image-taking mode (a recording type).

Abstract: The image-pickup apparatus includes an image-pickup element including first type pixels photoelectrically converting an object image formed by a light flux from an optical system and second type pixels photoelectrically converting plural images formed by plural light fluxes divided from the light flux from the optical system, a controller performing contrast detection focus control using signals from pixels in a contrast evaluation area among the first type pixels, and a detector detecting phase differences of respective pairs of images of the plural images using signals from the second type pixels, the pairs of images being respectively formed in plural phase difference detection areas in the contrast evaluation area, and calculating information on an in-focus position of the optical system or object distance for each phase difference detection area based on each phase difference.

Abstract: An imaging device includes a capturing module with at least one lens for capturing an image from a scene, a driving module for driving the at least one lens to different focusing positions using different driving steps, a flat-scene judging module, and a step-judging module. The flat-scene judging module divides the image into a central area and a plurality of peripheral areas, and determines whether the captured scene is a flat scene according to the divided image. The step-judging module determines whether the driving steps corresponding to a maximum focusing value of the central area of the image are same as driving steps corresponding to respective maximum focusing values of the peripheral areas of image, and changes the driving steps corresponding to the maximum focusing value of the central area to the driving steps corresponding to the greatest one of the maximum focusing values of the peripheral areas.

Abstract: A method of correcting an image signal generated by a charge coupled device (CCD) image sensor in an imaging system is provided. The imaging system stores a number of gamma correction curves, each of which includes a respective correction factor for increasing contrast in a dark portion of the image signal. The method includes: measuring gray scale value of each pixel of the CCD image sensor; estimating a contrast level of an object scene to be imaged using the measured gray scale values; and correcting the image signal using a corresponding gamma correction curve depending on the estimated contrast level of the object scene.