Method for generating output signal of PDAF pixel

Abstract

A method for generating an output signal of a PDAF pixel is provided. A method for generating an output signal of a PDAF pixel of an optoelectronic image sensor using pixel signals from additional pixels arranged in an environment of the PDAF pixel, wherein the image sensor has the PDAF pixel and at least one additional PDAF pixel in a pixel column extending along a first direction within the environment. The method includes detecting pixel signals of the pixels of the image sensor arranged in the environment, determining a structural direction of an image structure mapped on the image sensor from pixel signals of at least some of the pixels arranged in the environment, and generating the output signal of the PDAF pixel. In this regard, the output signal is generated as an interpolated signal in some cases from pixel signals of additional pixels arranged in the environment, and as an amplified signal by correcting the pixel signal of the PDAF pixel with an amplification factor in other cases, and the output signal of the PDAF pixel is generated as the amplified signal when the difference between the structural direction and the first direction is less than a predetermined angle.

Description

Technical Field

[0001] The present invention relates to a method for generating an output signal of a PDAF pixel of a photoelectronic image sensor and a sensor device including the photoelectronic image sensor.

Background Art

[0002] A photoelectronic image sensor including PDAF (phase difference detection autofocus) pixels is used, inter alia, in digital cameras such as photographic and video cameras to provide a phase comparison autofocus function. In a photoelectronic image sensor including integrated PDAF pixels, the PDAF pixels used for phase comparison are directly integrated into the image sensor, and no separate autofocus sensor is required. Therefore, a camera including such a sensor can have a particularly compact design, for example, as a mirrorless system camera.

[0003] PDAF pixels usually have a mask that partially covers the photosensitive area of each PDAF pixel, so that each PDAF pixel can receive radiation from an optical system to be focused only from a predetermined direction. PDAF pixels are usually divided into two groups, and these two groups of PDAF pixels receive radiation from different directions. Then, the focal position of the optical system can be determined based on the spatial phase shift of the images received from different directions on the image sensor, and the optical system can be focused.

[0004] However, the mask used for PDAF pixels has a drawback that a part of the radiation incident on the PDAF pixels is blocked by the mask. Therefore, the PDAF pixels do not transmit the same image information as normal pixels without a mask. Therefore, when an image recorded by an image sensor is generated using the pixel signals of the PDAF pixels, image errors usually occur in the images in the peripheral areas of the PDAF pixels.

Summary of the Invention

Problems to be Solved by the Invention

[0005] An object of the present invention is to provide a method for generating an output signal of a PDAF pixel of a photoelectronic image sensor and a sensor device including the photoelectronic image sensor that avoid image errors when generating an image recorded by the image sensor.

[0006] This object is achieved by the method and the sensor device according to the independent claims. Further developments are described in the dependent claims, respectively.

Means for Solving the Problem

[0007] A method for generating an output signal of a PDAF pixel of a photoelectronic image sensor using a pixel signal from a further pixel arranged in the environment of the PDAF pixel is disclosed. In the environment where the output signal is generated, the image sensor has the PDAF pixel and at least one further PDAF pixel in a pixel column extending along a first direction, and the method includes: · Detecting a pixel signal of the pixel of the image sensor arranged in the environment; · Determining a structural direction of an image structure mapped on the image sensor from pixel signals of at least some of the pixels arranged in the environment; and · Generating the output signal of the PDAF pixel.

[0008] In this regard, the output signal of the PDAF pixel is, in some cases, generated as an interpolation signal from pixel signals of further pixels arranged in the environment, and in other cases, generated as an amplified signal by correcting the pixel signal of the PDAF pixel with an amplification factor. When the difference between the structural direction and the first direction is less than a predetermined angle, the output signal of the PDAF pixel is generated as the amplified signal.

[0009] Since the output signal of the PDAF pixel is generated as an interpolation signal or an amplification signal according to individual cases, regardless of the structural direction of the mapped image structure, the actual image signal of the PDAF pixel can be reconstructed particularly accurately, and there is substantially no image error in the image generated from the image signal. The output signal of the PDAF pixel can be generated as an interpolation signal or an amplification signal particularly according to the determined structural direction.

[0010] In this regard, the structural direction is determined as the direction in which the contrast of the mapped image structure is the smallest and, as a result, the intensity at which the pixels of the image sensor are exposed is substantially the same. Therefore, when determining the image signal of the PDAF pixel by interpolation, the best results are obtained when the interpolation is performed along the structural direction and the output signal of the PDAF pixel is generated from additional pixels of the environment arranged around the PDAF pixel along the structural direction.

[0011] However, when the structural direction extends substantially parallel to the first direction and the PDAF pixels are also arranged adjacent to each other, since additional PDAF pixels are shielded from light by a mask in the same way as the PDAF pixels, complete information about the incident radiation cannot be obtained from at least the additional PDAF pixels. Therefore, when the image signals of the additional PDAF pixels are also used for interpolation, there may be an image error in the image generated from the output signal. When the difference between the structural direction and the first direction is less than a predetermined angle, that is, when the structural direction is substantially parallel to the first direction, the output signal of the PDAF pixel is generated as an amplification signal rather than an interpolation signal, so that image errors that may occur during interpolation along the first direction are avoided.

[0012] Depending on the design of the image sensor, in addition to the above-described cases, the output signal of the PDAF pixel may be generated, for example, by a combination of the above-described two signals, rather than as either the above-described interpolation signal or the above-described amplification signal. However, the output signal of the PDAF pixel may be generated only by the above-described two methods, in other words, as either an interpolation signal or an amplification signal.

[0013] A pixel column including PDAF pixels and additional PDAF pixels is also referred to as a PDAF pixel column. In a PDAF pixel column, in addition to the PDAF pixels, one or more of the additional pixels used for generating an interpolation signal can be similarly formed as PDAF pixels. All the PDAF pixels within the environment may be arranged only in the PDAF pixel column and not in other pixel columns of the environment. In the case of an image sensor, in particular, by forming all the pixels within the environment that are arranged in the PDAF pixel column and can be used for generating an interpolation signal as PDAF pixels, it can be made basically impossible to reconstruct the output signal of the PDAF pixels by interpolation along the PDAF pixel column.

[0014] The image sensor can be configured, in particular, as a color sensor including color-selective pixels. For example, the color-selective pixels can be formed as green, blue, and red pixels including green, blue, or red color filters. The color-selective pixels can be arranged at pixel positions on the image sensor that are distributed according to a predetermined color arrangement. The pixels can be arranged, in particular, according to a Bayer arrangement. The individual rows of the Bayer arrangement alternately include green and red pixel positions or green and blue pixel positions. In this regard, the green and red pixel positions or the green and blue pixel positions are also alternately arranged adjacent to each other along the individual rows. Also, since the green pixel positions in the green / red rows are shifted by one column from the green pixel positions in the green / blue rows in any case, the Bayer arrangement alternately has columns including green and red pixel positions and columns including green and blue pixel positions.

[0015] However, the image sensor can also be configured as a monochrome sensor that is designed without using color-selective pixels and in which each pixel is sensitive in the same spectral range.

[0016] The environment used for generating the output signal can be arranged symmetrically around the PDAF pixels. For example, the above environment may have the same range, for example, a range of 5 pixels, in a first direction and a normal direction oriented perpendicular to the first direction.

[0017] The pixels used for generating the interpolation signal may be, for example, all the pixels arranged in the environment in the direction used for interpolation beside the PDAF pixels and assigned the same color as the pixel position of the PDAF pixels, at the pixel positions of the color array of the image sensor. For example, the PDAF pixels and the pixels used for generating the interpolation signal may be located at the green pixel position, the red pixel position, or particularly the blue pixel position, respectively.

[0018] For example, the interpolation may be performed along a predetermined interpolation direction, for example, along a second direction oriented perpendicular to the first direction, or along a diagonal direction inclined at 45° with respect to the first and second directions. In particular, the interpolation may be performed excluding the first direction, and in that case, instead of the interpolation along the first direction, the pixel signal of the PDAF pixel may be corrected by the amplification factor. The above method may include a step of determining the interpolation direction used for interpolation. Each interpolation direction used for interpolation may be, for example, the direction in which the image signal difference of the additional pixels used for interpolation is minimized.

[0019] In the environment used for generating the output signal, the PDAF pixels and additional PDAF pixels can be arranged at pixel positions of the same color. In the case of an image sensor, in particular, all the pixels arranged at pixel positions of the same color in the PDAF pixel column, for example, all the pixels at the blue, red, or green pixel positions, can be formed as PDAF pixels in the environment used for generating the output signal. In this regard, particularly in the case of an image sensor including a Bayer array, the pixels of the PDAF pixel column can be formed as PDAF pixels in the environment every other one in particular. Furthermore, not only all the pixels of the same color arranged in the PDAF pixel column in the environment, but also all the pixels of the same color arranged in the PDAF pixel column outside the environment, for example, all the blue and / or every other pixel of the PDAF pixel column, can be formed as PDAF pixels.

[0020] The structural direction can be determined while considering only the pixels formed as pixels exposed over the entire area rather than as PDAF pixels among the pixels in the environment. The structural direction can be determined using only the pixel positions of pixels of only one color, for example, the pixels having the color of the pixel positions of the PDAF pixels. However, the structural direction can also be determined using, in particular, pixels arranged at pixel positions of different colors, for example, pixels at pixel positions of all colors.

[0021] The amplified signal can be generated by multiplying all the detected pixel signals of the PDAF pixels or only a part of the pixel signals of the PDAF pixels by an amplification factor. In this regard, the amplification factor may be the ratio of the total area of the PDAF pixels to the area of the region of the PDAF pixels darkened by the mask, that is, it may correspond to a factor of 2 in the case of PDAF pixels covered on one side.

[0022] Alternatively, the amplification factor g can also be determined from the signal ratio of the pixel signals of the pixels exposed over the entire area to the pixel signals of the light-shielding pixels formed as PDAF pixels. For example, the amplification factor g is

Equation

[0023] When the image sensor has a color filter, the pixels exposed over the entire area used for determining the signal ratio are each arranged at pixel positions of a color corresponding to the color of the pixel position of the PDAF pixel where the output signal is generated. In this regard, the PDAF pixel itself may have a color filter of a color corresponding to the color of the pixel position, or may have a color filter of a color different from the color of the pixel position.

[0024] The pixels used for determining the signal ratio can be arranged around the PDAF pixel where the output signal is generated in a predetermined environment. The predetermined environment may be, for example, the local environment of the PDAF pixel, and may include, for example, 2 or fewer, 4 or fewer, 8 or fewer, or 16 or fewer additional PDAF pixels. The predetermined environment may also be the entire PDAF pixel column in which each PDAF pixel is arranged. Alternatively, the predetermined environment may be the entire pixel area of the image sensor.

[0025] In a further development of the above method, only the signal portion of the pixel signal of the PDAF pixel that exceeds a predetermined dark signal of the PDAF pixel is scaled by an amplification factor, whereby the pixel signal of the PDAF pixel is corrected to generate an amplified signal.

[0026] The dark signal is the image signal output by the PDAF pixel in the non-exposed state. Since the value of the dark signal does not depend on the exposure of the PDAF pixel, when only the portion of the image signal of the PDAF pixel that depends on the exposure and exceeds the dark signal is scaled by the amplification factor, the amplified signal particularly accurately reproduces the signal generated when the PDAF pixel is exposed over the entire area.

[0027] The amplified signal y PDAF,G is determined, in particular,

Equation

[0028] In a further development of the above method, the predetermined angle is 0° or more, 10° or more, 13° or more, or 16° or more and / or 45° or less, 35° or less, 23° or less, or 20° or less, for example, 14°, 18°, or 22.5°. If the selection of the predetermined angle is too small, an output signal may be generated by interpolation even when the structural direction and the first direction deviate only slightly, and an interpolation error may occur especially when interpolation along the first direction is excluded. On the other hand, if the selection of the predetermined angle is too large, even when interpolation without error along the diagonal direction or the like would be actually possible, an output signal is generated by correcting the image signal of the PDAF pixel with an amplification factor, and the accuracy of reproducing the true image signal of the PDAF pixel may be lower than when interpolating.

[0029] In a further development of the above method, the structural direction is determined from the first contrast value and the second contrast value of the mapped image structure. The first contrast value refers to the contrast of the image structure along the first direction, and the second contrast value refers to the contrast of the image structure along a second direction different from the first direction, particularly, the second direction orthogonal to the first direction. In this way, the structural direction can be determined simply and quickly.

[0030] The structural direction can generally be determined by determining the angle between the structural direction and the first direction. The structural direction can particularly be determined from the ratio of the first contrast value and the second contrast value which is an index indicating the angle between the structural direction and the first direction. When the first direction and the second direction are arranged perpendicularly, the ratio of the second contrast value to the first contrast value corresponds particularly to the cotangent of the angle between the structural direction and the first direction. And when the ratio of the second contrast value to the first contrast value exceeds a threshold value derived from a predetermined angle, the difference between the structural direction and the first direction is less than the predetermined angle. The derived threshold value may be equal to, for example, the cotangent of the predetermined angle, and may be, for example, 6 or 3 or 2.4 or 2.

[0031] In a further development of the above method, the first contrast value is generated in the environment considering a plurality of first pixel pairs each including two of the further pixels arranged in a first pixel column of the image sensor extending along a first direction. Alternatively or in addition, the second contrast value is generated in the environment considering a plurality of second pixel pairs each including two of the further pixels arranged in a second pixel column of the image sensor extending along a second direction.

[0032] In either case, since a plurality of first pixel pairs or a plurality of second pixel pairs are used for determining the contrast value, the contrast value can be determined in a particularly robust manner without being unduly strongly affected by small variations in the mapped image structure with respect to the structural direction determined from the contrast value. The first contrast value and / or the second contrast value can be determined, for example, as the sum of the difference components of the pixel signals of the pixels of each individual first or second pixel pair.

[0033] Each pixel of each individual first pixel pair can be arranged symmetrically with respect to a vertical pixel column extending perpendicular to the first direction and including PDAF pixels. The vertical pixel column can in particular be formed by a pixel column of the image sensor including PDAF pixels. Each pixel of each individual further first pixel pair can also be arranged asymmetrically with respect to the vertical pixel column. For example, one pixel of each first pixel pair can be arranged in the vertical pixel column, and the other pixel of each first pixel pair can be arranged in the half of the environment used for generating the output signal of the PDAF pixel bounded by the vertical pixel column. Also, the plurality of first pixel pairs may include both a first pixel pair in which each pixel is arranged symmetrically with respect to the vertical pixel column including PDAF pixels and a first pixel pair in which each pixel is arranged asymmetrically with respect to the vertical pixel column including PDAF pixels.

[0034] Similarly, each pixel of each individual second pixel pair can be arranged symmetrically with respect to a PDAF pixel column extending along the first direction and including PDAF pixels. The pixels of each individual additional second pixel pair can also be arranged asymmetrically with respect to the PDAF pixel column. For example, one pixel of each second pixel pair can be arranged in the PDAF pixel column, and the other pixel of each second pixel pair can be arranged in the half of the environment used for generating the output signal of the PDAF pixel, bounded by the PDAF pixel column. Also, the plurality of second pixel pairs may include both a second pixel pair in which each pixel is arranged symmetrically with respect to the PDAF pixel column and a second pixel pair in which each pixel is arranged asymmetrically with respect to the PDAF pixel column.

[0035] In a further development of the above method, each first pixel pair is composed of two additional pixels of the same color, and / or each second pixel pair is composed of two additional pixels of the same color. Since each individual pixel pair includes pixels of the same color, the contrast value can be determined as the sum of the individual contrasts for each color, where the individual contrasts for each color are determined by the signal difference of the pixels of the same color in each individual pixel pair.

[0036] In a further development of the above method, the first contrast value includes the sum of the differential amounts of the pixel signals of the additional pixels of the individual first pixel pairs, and / or the second contrast value includes the sum of the differential amounts of the pixel signals of the additional pixels of the individual second pixel pairs. In this regard, the differential amount is obtained from the differential amounts of the pixels of the individual pixel pairs.

[0037] In a further development of the above method, the arrangement of the second pixel pair corresponds to the arrangement of the first pixel pair obtained by rotating around the PDAF pixel from the first direction to the second direction. In particular, the plurality of first pixel pairs and the plurality of second pixel pairs include the same number of pixel pairs. Further, the second pixel pair does not include pixels that are mapped to PDAF pixels such as further PDAF pixels when the arrangement of pixels in the environment of the PDAF pixel is rotated from the second direction to the first direction. Thereby, the signal difference of each first pixel pair for determining the first contrast value and the signal difference of each second pixel pair for determining the second contrast value are equally weighted, and when determining the structural direction, it is possible to prevent a preferred direction from occurring due to the non-uniform number and distribution of the first and second pixel pairs.

[0038] In a further development of the above method, the structural direction is determined from the pixel signals of pixels of different colors. In particular, the structural direction can be determined from the pixel signals of all-color pixels. In this way, the contrast direction can be determined with particularly high reliability. In particular, by including the plurality of first pixel pairs and / or the plurality of second pixel pairs as pixel pairs of different colors, the structural direction can be determined from the pixel signals of pixels of different colors.

[0039] In a further development of the above method, the structural direction is determined by excluding the pixel signals of the PDAF pixel and further PDAF pixels. In particular, by excluding all PDAF pixels included in the environment to determine the structural direction, for example, when determining the structural direction via the first and second contrast values, the PDAF pixel and at least one further PDAF pixel can be prevented from being included in any of the first and / or second pixel pairs. Since the PDAF pixel is partially shielded from light, it is not suitable for determining the structural direction via the first and second contrast values and the like. Each pixel pair used for determining the first and second contrast values can be formed from adjacent same-color pixels excluding the PDAF pixel and further PDAF pixels.

[0040] In a further development of the above method, at least when the structural direction is oriented perpendicular to the first direction, preferably in all cases where the difference between the structural direction and the first direction exceeds a predetermined angle, the output signal of the PDAF pixel is generated as an interpolation signal. In particular, the output signal of the PDAF pixel may generally always be generated as an interpolation signal, except when the difference between the structural direction and the first direction is less than or equal to a predetermined angle.

[0041] In a further development, the above method includes a step of determining at least two signal difference values, and each individual signal difference value is determined from the pixel signals of two pixels each of further pixels arranged on both sides of the PDAF pixel in a further direction extending through the PDAF pixel and being different for each individual signal difference value within the environment around the PDAF pixel. Also, the interpolation signal is generated from the pixel signal of a further pixel where the signal difference value is the smallest.

[0042] The signal difference values determined along different further directions are each an indicator showing the contrast of the mapped image structure along each further direction. And the further direction in which the signal difference value of the further pixel becomes the smallest corresponds to the direction in which the contrast becomes the smallest. Therefore, the mapped image structure is oriented along each direction, and it is assumed that the exposure of the PDAF pixel is performed at substantially the same intensity as the two further pixels used for determining the signal difference value along each direction. Since the interpolation signal is generated from the pixel signal of a further pixel where the signal difference value is the smallest, the interpolation signal particularly accurately corresponds to the image signal that can be obtained from the PDAF pixel when there is no mask on the PDAF pixel and it is exposed over the entire area.

[0043] The further pixels for determining the individual signal difference values can be arranged symmetrically or asymmetrically with respect to the PDAF pixel along each further direction. The further directions may particularly include a normal direction oriented perpendicular to the first direction and / or a diagonal direction inclined at 45° with respect to the first direction.

[0044] In a further development of the above method, the further directions are each different from the first direction. Therefore, in particular, interpolation along the PDAF pixel column oriented in the first direction is not performed. Since further PDAF pixels can be arranged in the PDAF pixel column, particularly at pixel positions of the same color as the pixel positions of the PDAF pixels, there is a risk that the output signals of the PDAF pixels are inaccurately generated in interpolation using the PDAF pixels. Instead of interpolation along the first direction, the output signals of the PDAF pixels are generated as amplified signals by the described method.

[0045] In a further development of the above method, the interpolation signal is generated as the average value of the pixel signals of further pixels with the smallest signal difference value, for example, as an arithmetic mean value or a weighted mean value. Such an average value is particularly easy to calculate and at the same time particularly accurately reproduces the signals generated during the global exposure of the PDAF pixels. The weighted mean value can be weighted, for example, by the distance of the individual pixels used to obtain the average value from the PDAF pixels.

[0046] In a further development of the above method, the signal difference value includes a diagonal signal difference value determined from the pixel signals of two further pixels arranged on both sides of the PDAF pixel in the diagonal direction extending through the PDAF pixel within the environment around the PDAF pixel. When determining the interpolation signal, not only the further direction oriented perpendicular to the first direction but also the diagonal direction is considered, so that the interpolation signal can particularly accurately reproduce the image signal generated during the global exposure of the PDAF pixel.

[0047] In a further development of the above method, the diagonal signal difference is determined from the pixel signals of two further pixels at an equal distance from the PDAF pixel in the diagonal direction when both of the two further pixels at an equal distance from the PDAF pixel in the diagonal direction are functioning, and the diagonal signal difference is determined from the pixel signals of two further pixels with different distances from the PDAF pixel in the diagonal direction when there is a defect in one of the further pixels at an equal distance from the PDAF pixel in the diagonal direction.

[0048] Additional pixels used to determine the signal difference may in any case be pixels of a predetermined color. The predetermined color may in particular be the color of the pixel position where the PDAF pixels are arranged. Each of the pixels equidistant from the PDAF pixel may in particular be a pixel of a predetermined color provided closest to the PDAF pixel in the diagonal direction.

[0049] The pixel signal of the closest pixel of the predetermined color typically has the smallest difference from the image signal generated during the full exposure of the PDAF pixel. Therefore, generally, using the pixel signal of the closest pixel can obtain the most accurate result for interpolation. However, in order to enable interpolation even when one of the two equidistant pixels has a defect, instead of the defective pixel at the equidistant position, a pixel provided farther away in the corresponding interpolation direction, for example, the second-closest pixel of a predetermined color, is used for interpolation.

[0050] In a further development of the above method, the signal difference value includes a further diagonal signal difference value determined from the pixel signals of two of the further pixels arranged on both sides of the PDAF pixel in a further diagonal direction extending through the PDAF pixel and oriented perpendicular to the diagonal direction within the environment around the PDAF pixel. When both diagonal directions are considered in interpolation, the interpolated signal approximates particularly accurately the image signal generated during the full exposure of the PDAF pixel.

[0051] In a further development of the above method, the signal difference value includes a vertical signal difference value determined from the pixel signals of two of the further pixels arranged on both sides of the PDAF pixel in the normal direction extending through the PDAF pixel and oriented perpendicular to the first direction within the environment around the PDAF pixel.

[0052] In a further development of the above method, the additional pixels used to determine the individual signal difference values are arranged at the pixel positions of the color filters of the image sensor of the color corresponding to the color of the pixel position of the PDAF pixel. Thereby, when selecting the additional direction used for interpolation, only the image structure of the same color as the pixel position of the PDAF pixel is considered, avoiding color errors during interpolation.

[0053] In a further development of the above method, the signal difference value is determined from the square root of each pixel signal used for the determination of the individual signal difference values. When the signal difference value is determined from the square root of the pixel signal, there is an advantage that the signal-dependent noise contribution of the individual pixel signals has less influence on the signal difference value compared to the case where the signal difference value is determined from the pixel signal itself. Since the noise of the individual pixel signals usually increases with exposure, otherwise, for the same exposure difference, the signal difference value of the pixels with less exposure will be smaller than that of the pixels with more exposure. As a result, the direction in which the exposure of the pixels is less than in other further directions may be prioritized during interpolation.

[0054] In a further development of the above method, each of the PDAF pixels and at least one further PDAF pixel has a mask that divides each PDAF pixel into an uncoated portion and a coated portion along a mask edge oriented perpendicular to the first direction. Therefore, when the difference between the structural direction and the first direction is less than a predetermined angle and the output signal of the PDAF pixel is generated as an amplified signal, the structural direction extends perpendicular to the mask edge that divides the PDAF pixel into an uncoated portion and a coated portion.

[0055] Therefore, the uncoated portion of the PDAF pixel and the coated portion of the PDAF pixel are each exposed with the same intensity. When the image signal detected by the partially coated PDAF pixel is corrected with a predetermined amplification factor, it is assumed that the signal generated at full exposure of the PDAF pixel is reproduced as a result. This may not be the case, for example, when the mask edge and the first direction are oriented parallel to each other. This is because, in that case, for example, the structural edge of the image structure mapped on the coated portion of the PDAF pixel extends along the mask edge of the PDAF pixel, so that the radiation incident on the uncoated portion of the PDAF pixel is independent of the interval. In the image sensor, all PDAF pixels in the environment used for the generation of the output signal can be divided into an uncoated portion and a coated portion, particularly along a mask edge extending perpendicular to the PDAF pixel column.

[0056] It is an independent aspect of the present invention that the mask edges of individual, multiple, or all PDAF pixels in a PDAF pixel column are oriented perpendicular to a first direction extending parallel to the PDAF pixel column, and in particular, it is independent of the method of generating the output signal of the PDAF pixel when the difference between the structural direction and the first direction exceeds a predetermined angle. Thus, in particular, the present invention generally relates to an image sensor including PDAF pixels arranged in individual PDAF pixel columns arranged parallel to each other and having mask edges oriented perpendicular to the individual PDAF pixel columns, and to a method or an image sensor for generating an output signal of the PDAF pixel as an amplified signal when the difference between the structural direction of the mapped image structure and the first direction is less than a predetermined angle.

[0057] In a further development of the above method, in an environment, PDAF pixels and further PDAF pixels are arranged at pixel positions of the same color that are closest to each other in the first direction. When individual PDAF pixels are arranged particularly close to each other, the phase difference between portions of incident electromagnetic radiation hitting the image sensor from different directions, and thus the focal position of the focusing optical system, can be determined particularly accurately. Further, arranging the PDAF pixels at pixel positions of the same color has the effect that only the pixels of one color are changed in the environment of the PDAF pixel column, so that the pixel signals of all the remaining colors can be detected correctly.

[0058] In a further development of the above method, the image sensor includes a color filter array in which all the pixels arranged in a PDAF pixel column extending along the first direction and including PDAF pixels have the same filter color. In particular, the PDAF pixels and further pixels exposed over the entire area have color filters of the same filter color in the PDAF pixel column. In this regard, the PDAF pixels can be arranged in any case at pixel positions of a color filter array to which a color different from the filter color of the color filter of the PDAF pixel is assigned. Further, the further pixels of the PDAF pixel column formed over the entire area can be arranged at pixel positions of a color corresponding to the filter color of the pixels arranged in the PDAF pixel column, respectively.

[0059] For example, in a Bayer color filter array, all PDAF pixels can be arranged at blue or red pixel positions in a PDAF pixel column and may include color filters of different colors rather than blue or red color filters, while all additional pixels are arranged at green pixel positions within the PDAF pixel column and include green color filters. However, all PDAF pixels can also be arranged at green pixel positions in a PDAF pixel column and may include color filters of different colors rather than green color filters, while all additional pixels are arranged at blue or red pixel positions within the PDAF pixel column and include blue or red color filters.

[0060] A sensor device further includes a photoelectronic image sensor and an evaluation device for generating an output signal of the PDAF pixels of the photoelectronic image sensor. The evaluation device is configured to generate the output signal of the PDAF pixels using pixel signals from further pixels of the image sensor arranged in the environment of the PDAF pixels. Within the environment used for generating the output signal, the image sensor has the PDAF pixels and at least one further PDAF pixel in a pixel column extending along a first direction. The evaluation device is configured to detect the pixel signals of the pixels of the image sensor arranged within the environment and to determine the structural direction of an image structure mapped onto the image sensor from the pixel signals of at least some of the pixels arranged within the environment. Further, the evaluation device is configured to generate the output signal of the PDAF pixels as an interpolation signal from the pixel signals of further pixels arranged within the environment in some cases, or as an amplified signal by correcting the pixel signal of the PDAF pixel with an amplification factor in other cases, and the evaluation device is configured to generate the output signal of the PDAF pixels as the amplified signal when the difference between the structural direction and the first direction is less than a predetermined angle.

[0061] The evaluation device of the above-described sensor device is particularly configured to execute the above-described method. In this regard, all the advantages and further developments described in relation to the above method also relate to the above sensor device or evaluation device.

[0062] The present invention further relates to a camera including the above-described sensor device. The above camera can be configured as a mirrorless camera such as a mirrorless system camera, in particular.

[0063] Hereinafter, the present invention will be described with reference to the drawings.

Brief Description of the Drawings

[0064]

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Embodiments for Carrying Out the Invention

[0065] A sensor device 1 including a photoelectronic image sensor 100 and an evaluation device 10 is shown in FIG. 1. A subject 30 is mapped as an image structure 32 onto the photoelectronic image sensor 100. In the photoelectronic image sensor 100, individual pixels are regularly arranged, and each individual pixel generates a pixel signal 106 corresponding to the intensity of electromagnetic radiation incident on the individual pixel, which is predetermined by the image structure 32. The evaluation device 10 is connected to the photoelectronic image sensor 100 and generates an output signal 11 by detecting and processing the pixel signal 106. The evaluation device 10 is configured to generate the output signal 11 such that the output signal 11 represents as accurately as possible the intensity actually incident on the individual pixels of the image sensor 100. The evaluation device 11 is configured to generate a corrected output signal 11 particularly for the partially darkened PDAF pixels of the photoelectric image sensor 100. The sensor device 1 is arranged in a digital camera not shown in FIG. 1.

[0066] FIG. 2 shows a cross-section of the photoelectronic image sensor 100, which includes a PDAF pixel column 120 along which PDAF pixels 112 are arranged. The PDAF pixel column 120 is formed by a pixel column of the photoelectronic image sensor 100 oriented along a first direction 101. In a second direction 102 that is oriented perpendicular to the first direction 101 and forms a normal direction, the image sensor 100 includes, for example, further PDAF pixel columns 120 (not shown) arranged at regular intervals from each other. Since each of the PDAF pixels 112 is covered on one side by a mask 115, the incident radiation hits only the uncovered portion of the PDAF pixel 112 adjacent to the mask 115.

[0067] As can be seen from FIG. 2, the optoelectronic image sensor 100 has a color filter array formed as a Bayer array including green pixel positions G, blue pixel positions B, and red pixel positions R. The pixels of the image sensor 100 arranged at the individual pixel positions G, B, R each include a color filter of a color corresponding to the color of the corresponding pixel position G, B, R, unless they are arranged in the PDAF pixel column 120.

[0068] Within the PDAF pixel column 120, the PDAF pixels 112 are in each case arranged at the blue pixel positions. However, the PDAF pixels 112 have color filters of a different color instead of blue color filters. Between the individual PDAF pixels 112, further pixels that are exposed over the entire area are arranged at all the green pixel positions G of the color filter array having a green color filter in the PDAF pixel column 120.

[0069] Two types of PDAF pixels 112 are arranged in the PDAF pixel column 120, with the opposite sides being covered in the first direction. That is, the type of PDAF pixel 112 with the left side covered and the type of PDAF pixel 112 with the right side covered are arranged. In this regard, the pixel column 120 in each case alternately includes three PDAF pixels 112 with the left side covered arranged adjacent to each other at the same - color pixel positions and three PDAF pixels 112 with the right side covered arranged adjacent to each other at the same - color pixel positions.

[0070] FIG. 3 shows the environment 110 of each PDAF pixel 112 used to generate the output signal 11 of one pixel among the PDAF pixels 112. The PDAF pixel 112 whose output signal 11 is determined based on the environment 110 is arranged at the center within the environment 110, and the environment 110 has a width of five pixels in each case along the first direction 101 and the second direction 102. Since every other pixel in the PDAF pixel column 120 is a PDAF pixel, two further PDAF pixels 114 are arranged on both sides of the PDAF pixel 112 in the PDAF pixel column 120 within the environment 110.

[0071] As also shown in FIG. 3, the masks 115 of the PDAF pixels 112, 114 divide the respective PDAF pixels 112, 114 along each mask edge 116 extending parallel to the second direction 102 into an uncovered portion, i.e., an exposed portion 119, and a covered portion, i.e., a non-exposed portion 118. All the remaining pixels in the environment 110 are formed as additional pixels 117 that are exposed over the entire area.

[0072] Since the PDAF pixels 112, 114 are each blocked by the mask 115, their pixel signals 106 cannot be directly used as the output signal 11. Therefore, the evaluation device 10 is configured to generate the output signals 11 of the PDAF pixels 112, 114 as interpolation signals or amplification signals using the pixel signals 106 of the pixels provided in the environment around each of the PDAF pixels 112, 114 in any case. The environment 110 shown in FIG. 3 is used in particular to generate the output signal 11 of the PDAF pixel 112 shown in FIG. 3 provided at the center of the environment 110. To generate the output signal 11 of the additional PDAF pixel 114 shown in FIG. 3, environments centered on the respective additional pixels 114 are similarly used.

[0073] Whether the output signal 11 of the PDAF pixel 112 is generated as an interpolation signal or an amplification signal depends on how the image structure 32 mapped on the image sensor 100 is oriented in the region of the environment 110 around the PDAF pixel 112. The method by which the output signal 11 is generated depends in particular on the structural direction of the image structure 32 in which the boundary line between the bright region and the dark region of the image structure 32 extends. The image structure 32 shown in FIG. 1 is structured, for example, into a bright region and a dark region, and the boundary line between the bright region and the dark region forms the structural edge 33 and defines the structural direction of the image structure 32.

[0074] As shown in FIG. 4, the structural direction of the image structure 32 in the environment 110 is defined by the angle 22 between the structural end 33 extending along the structural direction and the first direction 101. In all cases where the angle 22 corresponds to a predetermined angle (for example, 18° or 22.5°) or less, that is, when the structural direction extends substantially along the first direction 101, the output signal 11 is determined as an amplified signal from the pixel signal 106 of the PDAF pixel 112. In all other cases, the output signal 11 is generated as an interpolation signal from the image signals 106 of additional pixels 117 arranged around the PDAF pixel 112 in the environment 110.

[0075] To determine the structural direction, the evaluation device 10 determines a first contrast value indicating the contrast of the image structure 32 along the first direction 101 and a second contrast value indicating the contrast of the image structure 32 along the second direction 102. As shown in FIG. 5, the first contrast value is determined based on a plurality of first pixel pairs 130, and each individual first pixel pair 130 includes two pixels of the same color respectively arranged in a common first pixel column 134 extending along the first direction 101. The first pixel column 134 is formed, in particular, by a pixel row of the image sensor 100.

[0076] Similarly, as shown in FIG. 6, the second contrast value is determined based on a plurality of second pixel pairs 140. Each individual second pixel pair 140 includes two pixels of the same color respectively arranged in a common second pixel column 144 extending along the second direction 102. The second pixel column 144 is formed, in particular, by a pixel column of the image sensor 100. In this regard, the arrangement of the second pixel pairs 140 corresponds to the arrangement obtained by rotating the first pixel pairs 130 from the first direction 101 to the second direction 102, that is, a 90° rotation.

[0077] The first contrast value (also referred to as the horizontal contrast value) is the sum of the difference components of the pixel signals 106 of the pixels of the individual first pixel pairs 130. For the individual pixel signals y of the i-th first pixel pair 130 1,i , y 2,i the difference component |c h,i | = |y 2,i -y 1,iIt is obtained as follows using

Number

[0078] Similarly, the second contrast value (also referred to as the vertical contrast value) is the sum of the difference components of the pixel signals 106 of the pixels of the second pixel pair 140. For the individual pixel signals y of the i-th second pixel pair 140 1,i , y 2,i The difference component |c v,i | = |y 2,i - y 1,i It is obtained as follows using

Number

[0079] The plurality of horizontally oriented first pixel pairs 130 shown in FIG. 5 includes both a first pixel pair 130 that is oriented along the second direction 102 and has pixels symmetrically arranged with respect to the central pixel column 122 including the PDAF pixel 112, and a first pixel pair 130 that has pixels asymmetrically arranged with respect to the central pixel column 122. For example, the pixels of the blue and green first pixel pairs 130 are symmetrically arranged with respect to the central pixel column 122 in the outermost first pixel column 134 arranged at the outer edge of the environment 110 in the second direction 102. Similarly, the pixels of the green first pixel pair 130 arranged in the PDAF pixel column 120, and the pixels of the red first pixel pair 130 in the first pixel column 134 provided between the PDAF pixel column 120 and the two outermost first pixel columns 134 in the second direction 102 are symmetrically arranged with respect to the central pixel column 122. In contrast, the pixels of the green first pixel pair 130 arranged in the first pixel column 134 provided between the PDAF pixel column 120 and the outermost first pixel column 134 in the second direction 102 are asymmetrically arranged with respect to the central pixel column 122.

[0080] Similarly, the plurality of vertically oriented second pixel pairs 140 shown in FIG. 6 also includes both a second pixel pair 140 that has pixels symmetrically arranged with respect to a further central pixel column formed by the PDAF pixel column 120, and a second pixel pair 140 that has pixels asymmetrically arranged with respect to the further central pixel column. For example, the pixels of the second pixel pair 140 arranged in the second pixel column 144 of the outermost environment 110 in the first direction 101 are symmetrically arranged with respect to the further central pixel column formed by the PDAF pixel column 120, while the pixels of the green second pixel pair 140 arranged in the second pixel column 144 provided between the central pixel column 122 and the two outermost second pixel columns 144 in the first direction 101 are asymmetrically arranged with respect to the further central pixel column.

[0081] The contrast ratio obtained from the second contrast value and the first contrast value

Number

[0082] As shown in FIG. 7, interpolation is performed along an interpolation direction different from the first direction 101, particularly along any of the diagonal direction 103, a further diagonal direction 104, or the normal direction 105 corresponding to the second direction 102. The interpolated signal is generated from the pixel signals of further pixels 150 that are provided closest to the PDAF pixel 112 along the interpolation direction used and have the same color pixel position as the pixel position of the PDAF pixel 112, that is, the blue pixel position in the case of the image sensor 100 shown in FIG. 7.

[0083] During interpolation along the first diagonal direction 103, the output signal 11 of the PDAF pixel 112 is generated from the pixel signals of the blue pixels arranged at the upper right and lower left corners of the environment 110. During interpolation along the further diagonal direction 104, the output signal 11 of the PDAF pixel 112 is generated from the pixel signals of the pixels arranged at the upper left and lower right corners of the environment 110. During interpolation along the normal direction 105, the output signal 11 of the PDAF pixel 112 is generated from the pixel signals of the blue pixels arranged at the upper and lower edges of the environment 110 in the same column as the PDAF pixel 112.

[0084] One of the directions 102, 103, 105 is selected as the interpolation direction in which the signal difference value between the pixel signals of the closest pixels 150 used for interpolation is minimized. In this regard, the individual signal difference value d of the j-th further direction 102, 103, 105 j is the individual pixel signal y1 j , y2 jIt is determined as the difference between the square roots as follows.

Number

[0085] Interpolated signal y PDAF,I corresponds to the average value of the pixel signals of two blue pixels 150 provided closest to both sides of the PDAF pixel 112 along the selected interpolation direction. For example, the interpolated signal y PDAF,I may correspond to the arithmetic mean value of the above pixel signals and can be calculated as follows.

Number

[0086] Fig. 8 shows an image sensor 100 with different arrangements of the PDAF pixels 112, 114. In this regard, the PDAF pixels 112, 114 are located at the green pixel positions instead of the blue pixel positions within the PDAF pixel column 120. In the Bayer color array, only the green pixel positions are arranged along the diagonal directions 103, 104 extending through the green pixel position G. Therefore, the environment 110 arranged around the PDAF pixel 112 to be corrected includes two pixels each with a green color filter on both sides of the PDAF pixel 112 along the diagonal directions 103, 104.

[0087] In another arrangement of the PDAF pixels 112 and 114 shown in FIG. 8, in this regard, when interpolating along the diagonal directions 103 and 104, the interpolation signal can be generated not only from the pixel 150 of the same color that is closest to the PDAF pixel 112, but also from the pixel 151 of the same color that is second closest to the PDAF pixel 112, that is, the green pixel at the corner of the environment 110. In this regard, as shown for the further diagonal direction 104 in FIG. 8, when the closest pixels 150 of the same color that are equidistant function in their respective diagonal directions 103 and 104, the signal difference value and the interpolation signal can be determined from the closest pixels 150 of the same color that are equidistant in the individual diagonal directions 103 and 104.

[0088] However, if one of the closest pixels 150 of the same color has a defect, as shown for the diagonal direction 103 in FIG. 8, instead of the pixel signal of the defective closest pixel 150, the pixel signal of the second closest pixel 151 of the same color in the corresponding diagonal directions 103 and 104 can be used to determine the signal difference value and the interpolation signal. In this case, the signal difference value and the interpolation signal can be generated, in particular, from pixels of the same color having different distances from the PDAF pixel 112 along the corresponding diagonal directions 103 and 104.

[0089] A method for generating the output signal 11 of the PDAF pixel 112 is shown in FIG. 9. The method 200 includes, as a first step, a step of detecting (201) the pixel signal 106 of the pixels of the image sensor 100 by the evaluation device 10. The method 200 then includes a step of interpolating (205) the pixel signal of the PDAF pixel 112 from the pixel signals 106 of further pixels 117 arranged in the environment "110". For this purpose, first the signal difference value d j is determined (210), and then the average value of the pixel signals of the closest pixels of the same color is determined (215) along the interpolation directions 103, 104, and 105 where the signal difference value is minimized. Finally, the interpolation signal thus generated is first defined (220) as the output signal.

[0090] Method 200 subsequently includes a step of determining (225) the structural direction of the image structure 32 provided by the structural end 33. When the difference between the structural direction and the first direction 101 is less than or equal to a predetermined angle, method 200 corrects (230) the pixel signal 106 of the PDAF pixel 112 with a predetermined amplification factor g to obtain an amplified signal

Number

[0091] In the method 200 shown in FIG. 9, the determination 205 of the interpolation signal is always performed, and the interpolation signal is replaced by the amplified signal only when the difference between the structural direction and the first direction 101 is less than or equal to a predetermined angle. When the predetermined angle is less than 45°, especially 18° or 22.5°, the difference between the structural direction and the first direction 101 is, on average, often greater than the predetermined angle rather than less than the predetermined angle. Therefore, the output signal 11 of the PDAF pixel 112 can be generated particularly quickly by the sequence of the determination 205 of the interpolation signal and the determination 230 of the amplified signal performed by method 200.

[0092] FIG. 10 shows another embodiment of a method 200 in which the structural direction is first determined (225) after the detection 201 of the pixel signal. When the difference between the structural direction and the first direction 101 is equal to or less than a predetermined angle, correction 230 by an amplification factor is performed, and the amplified signal is defined 235 as the output signal. When the difference between the structural direction and the first direction 101 exceeds the predetermined angle, in the method shown in FIG. 10, as already described in connection with FIG. 9, interpolation 205 of the pixel signal of the PDAF pixel 112 from the pixel signal 106 of the further pixel 117 arranged in the environment 110 is performed. Finally, the output signal is generated (240) as the amplified signal or the interpolated signal.

Explanation of Signs

[0093] 1 Sensor device 10 Evaluation device 11 Output signal 22 Angle 30 Subject 32 Image structure 33 Structural end 100 Image sensor 101 First direction 102 Second direction 103 Diagonal direction 104 Further diagonal direction 105 Normal direction 106 Pixel signal 110 Environment 112 PDAF pixel 114 Further PDAF pixel 115 Mask 116 Mask end 117 Further pixel 118 Covering portion 119 Non-covered portion 120 PDAF pixel column 122 Central pixel column 130 First pixel pair 134 First pixel column 140 Second pixel pair 144 Second pixel column 150 Nearest pixel 151 Second nearest pixel 200 Method for generating an output signal Detection of 201 pixel signals Interpolation 205 Determination of signal difference value 210 Determination of average value 215 Define the interpolated signal as the output signal 220 Determination of structural direction 225 Correction by amplification factor 230 Define the amplified signal as the output signal 235 Generation of output signal 240

Claims

1. A method (200) for generating an output signal (11) of a PDAF pixel (112) of a photo - electronic image sensor (100) using a pixel signal (106) from a further pixel (117) arranged in the environment (110) of the PDAF pixel (112), within the environment (110) in which the output signal (11) is generated, the image sensor (100) has the PDAF pixel (112) and at least one further PDAF pixel (114) in a pixel column extending along a first direction (101), the method (200) comprising: a step of detecting (201) pixel signals (106) of the pixels (112, 114, 117) of the image sensor (100) arranged within the environment (110); a step of determining (225) a structural direction of an image structure (32) mapped onto the image sensor (100) from pixel signals (106) of at least some of the pixels among the pixels (117) arranged within the environment (110), and a step of generating (240) the output signal (11) of the PDAF pixel (112), wherein the structural direction is the direction in which the contrast of the mapped image structure (32) is the smallest, the output signal (11) of the PDAF pixel (112) is, in some cases, generated as an interpolation signal from the pixel signal (106) of a further pixel (117) arranged within the environment (110), and in other cases, is generated as an amplified signal by correcting (230) the pixel signal (106) of the PDAF pixel (112) with an amplification factor; the method (200), wherein when the difference between the structural direction and the first direction (101) is less than a predetermined angle, the output signal (11) of the PDAF pixel (112) is generated as the amplified signal.

2. The method (200) according to claim 1, wherein only the signal portion of the pixel signal (106) of the PDAF pixel (112) that exceeds a predetermined dark signal of the PDAF pixel (112) is scaled by the amplification factor, thereby correcting the pixel signal (106) of the PDAF pixel (112) to generate the amplified signal.

3. The method (200) according to claim 1 or 2, wherein the predetermined angle is 0° or more and / or 45° or less.

4. The structural direction is determined from a first contrast value and a second contrast value of the mapped image structure (32). The first contrast value refers to the contrast of the image structure (32) along the first direction (101), and the second contrast value refers to the contrast of the image structure (32) along a second direction (102) different from the first direction (101), in particular along a second direction orthogonal to the first direction (101). The method (200) according to any one of claims 1 to 3.

5. The first contrast value is generated in consideration of a plurality of first pixel pairs (130) each including two of the further pixels (117) arranged in the first pixel column (134) of the image sensor (100) extending along the first direction (101) within the environment (110), and / or The second contrast value is generated in consideration of a plurality of second pixel pairs (140) each including two of the further pixels (117) arranged in the second pixel column (144) of the image sensor (100) extending along the second direction (102) within the environment (110). The method (200) according to claim 4.

6. Each first pixel pair (130) is composed of two further pixels (117) that are each the same color, and / or each second pixel pair (140) is composed of two further pixels (117) that are each the same color. The method (200) according to claim 5.

7. The first contrast value includes the sum of the difference components of the pixel signals (106) of the further pixels (117) of the individual first pixel pairs (130), and / or The second contrast value includes the sum of the difference components of the pixel signals (106) of the further pixels (117) of the individual second pixel pairs (140). The method (200) according to claim 5 or 6.

8. The arrangement of the second pixel pair (140) corresponds to the arrangement of the first pixel pair (130) rotated from the first direction (101) to the second direction (102) around the PDAF pixel (112). The method (200) according to any one of claims 5 to 7.

9. The structural direction is determined from the pixel signals (106) of pixels (117) of different colors. The method (200) according to any one of claims 1 to 8.

10. The structural direction is determined by excluding the pixel signals (106) of the PDAF pixel (112) and the further PDAF pixel (114). The method (200) according to any one of claims 1 to 9.

11. When the above structural direction is oriented perpendicular to the above first direction (101), preferably, in all cases where the difference between the above structural direction and the above first direction (101) exceeds the above predetermined angle, the above output signal (11) of the above PDAF pixel (112) is generated as the above interpolation signal, the method (200) according to any one of claims 1 to 10.

12. The above method (200) includes a step of determining (210) at least two signal difference values, Each individual signal difference value is determined from the pixel signals (106) of two pixels each among the above additional pixels (117) arranged on both sides of the above PDAF pixel (112) in the above environment (110) around the above PDAF pixel (112), extending through the above PDAF pixel (112) and in further directions (102, 103, 104, 105) that are different for each individual case of the individual signal difference values, The above interpolation signal is generated from the pixel signal (106) of the above additional pixel (117) with the smallest signal difference value, the method (200) according to any one of claims 1 to 11.

13. The above further directions (102, 103, 104, 105) are each different from the above first direction (101), the method (200) according to claim 12.

14. The above interpolation signal is generated as the average value of the pixel signal (106) of the above additional pixel (117) with the smallest signal difference value, for example, as an arithmetic average value or a weighted average value, the method (200) according to claim 12 or 13.

15. The above signal difference value includes a diagonal signal difference value determined from the pixel signals (106) of two additional pixels (117) arranged on both sides of the above PDAF pixel (112) in a diagonal direction (103) extending through the above PDAF pixel (112) within the above environment (110) around the above PDAF pixel (112), the method (200) according to any one of claims 12 to 14.

16. The above diagonal signal difference is determined from the pixel signals (106) of the two additional pixels (117) equidistant from the above PDAF pixel (112) in the above diagonal direction (103) when both of the two additional pixels (117) equidistant from the above PDAF pixel (112) are functioning, The diagonal signal difference is determined from the pixel signals (106) of two further pixels (117) having different distances from the PDAF pixel (112) in the diagonal direction (103) when there is a defect in one of the further pixels (117) equidistant in the diagonal direction (103), the method (200) according to claim 15.

17. The signal difference value includes a further diagonal signal difference value determined from the pixel signals (106) of two of the further pixels (117) arranged on both sides of the PDAF pixel (112) in a further diagonal direction (104) extending through the PDAF pixel (112) and oriented perpendicular to the diagonal direction (103) within the environment (110) around the PDAF pixel (112), the method (200) according to claim 15 or 16.

18. The signal difference value includes a vertical signal difference value determined from the pixel signals (106) of two of the further pixels (117) arranged on both sides of the PDAF pixel (112) in a normal direction (102, 105) extending through the PDAF pixel (112) and oriented perpendicular to the first direction (101) within the environment (110) around the PDAF pixel (112), the method (200) according to any one of claims 12 to 17.

19. The further pixels (117) used for determining the individual signal difference values are arranged at the pixel positions of the color filter of the image sensor (100) of a color corresponding to the color of the pixel position of the PDAF pixel (112), the method (200) according to any one of claims 12 to 18.

20. The signal difference value is determined from the square root of each pixel signal (106) used for determining the individual signal difference values, the method (200) according to any one of claims 12 to 19.

21. The PDAF pixel (112) and the at least one further PDAF pixel (114) each have a mask (115) that divides each PDAF pixel (112, 114) into an uncoated portion (119) and a coated portion (118) along a mask edge (116) oriented perpendicular to the first direction (101), the method (200) according to any one of claims 1 to 20.

22. In the above environment (110), the PDAF pixel (112) and the additional PDAF pixel (114) are arranged at pixel positions of the same color that are closest to each other in the first direction (101). The method (200) according to any one of claims 1 to 21.

23. The image sensor (100) includes a color filter array in which all the pixels (112, 114, 117) arranged in a PDAF pixel column (120) that extends along the first direction (101) and includes the PDAF pixels (112, 114) have the same filter color. The method (200) according to any one of claims 1 to 22.

24. A sensor device (1) including a photoelectronic image sensor (100) and an evaluation device (10) for generating an output signal (11) of a PDAF pixel (112) of the photoelectronic image sensor (100), The evaluation device (10) is configured to generate the output signal (11) of the PDAF pixel (112) using a pixel signal (106) from a further pixel (117) of the image sensor (100) arranged in the environment (110) of the PDAF pixel (112), In the environment (110) used for generating the output signal (11), the image sensor (100) has the PDAF pixel (112) and at least one additional PDAF pixel (114) in a pixel column extending along the first direction (101), The evaluation device (10) is configured to detect the pixel signal (106) of the pixel (117) of the image sensor (100) arranged in the environment (110) and to determine the structural direction of an image structure (32) mapped onto the image sensor (100) from the pixel signals (106) of at least some of the pixels (112, 114, 117) arranged in the environment (110), The structural direction is the direction in which the contrast of the mapped image structure (32) is the smallest, The evaluation device (10) is configured to generate the output signal (11) of the PDAF pixel (112) as an interpolation signal from the pixel signal (106) of a further pixel (117) arranged in the environment (110) in some cases, and to generate it as an amplified signal by correcting the pixel signal (106) of the PDAF pixel (112) with an amplification factor in other cases. The above evaluation device (10) is configured to generate the output signal (11) of the above PD AF pixel (112) as the above amplification signal when the difference between the above structural direction and the above first direction (101) is less than a predetermined angle, and is a sensor device (1).

25. A camera including the sensor device (1) according to claim 24.

Images