Color imaging system

Abstract

A color imaging system is provided to achieve high color resolution and HDR images, the system having an image sensor, including an image sensor, a color filter and an image processing unit, wherein all units of the color filter include at least one filter pixel of a first color that mainly contributes to generating a brightness signal, and the remaining filter pixels are a second color or a third color, each filter pixel is assigned a long exposure or a short exposure, the image sensor sequentially outputs a first color signal, a second color signal and a third color signal with a long exposure or a short exposure using a line buffer, and the image processing unit performs pixel addition, interpolation of long exposure and short exposure, and HDR synthesis to generate an HDR color image signal.

Description

Technical Field

[0001] The present disclosure relates to a color imaging system, and more particularly, to a system including an image sensor, a color filter, and an imaging processing unit, which achieves improvements in both color resolution and high dynamic range (HDR) images. Background Art

[0002] In recent years, color imaging systems have been developed and widely used in, for example, mobile phones. With the development of high-speed / large-capacity data communications or high-speed microprocessors, high color resolution is required.

[0003] It is known that the conventional color imaging system has the following problems.

[0004] For example, in a system using a Bayer filter, each pixel of the image sensor generates only one color signal among the three colors of red (R), green (G), and blue (B). Therefore, interpolation is required to generate two color signals of the other two colors. As a result, false signals such as aliasing noise are generated due to interpolation.

[0005] Another conventional system includes a dichroic prism and three image sensors. The three image sensors generate three color signals respectively, and no interpolation is required. No aliasing signals are generated, and the color resolution is high. However, the configuration of this system is complicated, the size is increased, and the cost is extremely high.

[0006] On the other hand, it is difficult to capture a clear image under shooting conditions with large brightness differences. That is, when there are parts with large brightness differences in the image (high dynamic range), long exposure results in overexposure of the high-brightness part and short exposure results in underexposure of the low-brightness part.

[0007] As described above, conventional color imaging systems cannot achieve both improvement in color resolution and improvement in HDR images at low cost. Summary of the invention

[0008] The present disclosure is made in view of the above circumstances, and thus the present disclosure provides a color imaging system for improving color resolution and HDR images at a low cost.

[0009] According to one aspect of the present disclosure, there is provided a color imaging system, comprising:

[0010] an image sensor including a plurality of image sensor pixels and outputting a first color signal, a second color signal, and a third color signal;

[0011] a color filter disposed on the plurality of image sensor pixels of the image sensor; and

[0012] an image processing unit that receives the first color signal, the second color signal, and the third color signal from the image sensor, performs predetermined processing on the first color signal, the second color signal, and the third color signal, and outputs a color image signal,

[0013] wherein the color filter comprises a plurality of cells, each of the cells corresponds to an image sensor pixel of the image sensor and each of the cells comprises a plurality of filter pixels, and wherein all cells comprise at least one filter pixel of a first color that primarily contributes to generating a luminance signal, the remaining filter pixels of the cell are of the second color or the third color, and each of the filter pixels is assigned a long exposure or a short exposure,

[0014] The image sensor uses a line buffer to sequentially output the first color signal, the second color signal, and the third color signal with long exposure or short exposure,

[0015] The image processing unit performs pixel addition on the second color signal and the third color signal, performs long exposure and short exposure interpolation on the first color signal with long exposure and with short exposure, the second color signal with long exposure and with short exposure, and the third color signal with long exposure and with short exposure, and performs HDR synthesis on the first color signal with long exposure and with short exposure, the second color signal with long exposure and with short exposure, and the third color signal with long exposure and with short exposure to generate an HDR color image signal.

[0016] In some embodiments, all filter pixels of the first color included in each cell may be assigned the same exposure of long exposure or short exposure, and the filter pixels of the first color may be assigned long exposure or short exposure alternately along rows or columns on a cell-by-cell basis.

[0017] In some embodiments, all filter pixels of the second color included in each cell may be assigned the same exposure of the long exposure or the short exposure, and all filter pixels of the third color included in each cell may be assigned the same exposure of the long exposure or the short exposure,

[0018] All filter pixels of the second color included in the cells along the rows or columns may be assigned the same exposure of the long exposure or the short exposure, and the filter pixels of the second color may be assigned the long exposure or the short exposure alternately row by row or column by column, and all filter pixels of the third color included in the cells along the rows or columns may be assigned the same exposure of the long exposure or the short exposure, and the filter pixels of the third color may be assigned the long exposure or the short exposure alternately row by row or column.

[0019] In some embodiments, cells along rows or columns including all filter pixels of the second color assigned with long exposure or short exposure, and cells along the same rows or columns including all filter pixels of the third color assigned with short exposure or long exposure are arranged alternately.

[0020] In some embodiments, the line buffer may be used to sequentially output the first color signal of long exposure and the first color signal of short exposure from the image sensor.

[0021] The second color signal of long exposure and the third color signal of short exposure, or the second color signal of short exposure and the third color signal of long exposure may be sequentially output from the image sensor using the line buffer.

[0022] In some embodiments, interpolation of long exposure and short exposure may be performed on the first color signal of long exposure and the first color signal of short exposure stored in the line buffer to generate the first color signal of long exposure in one frame and the first color signal of short exposure in one frame.

[0023] Long exposure and short exposure interpolation can be performed on the second color signal of long exposure, the third color signal of short exposure, the second color signal of short exposure, and the third color signal of long exposure stored in the line buffer to generate the second color signal of long exposure in one frame, the second color signal of short exposure in one frame, the third color signal of long exposure in one frame, and the third color signal of short exposure in one frame.

[0024] In some embodiments, each of the cells of the color filter may include filter pixels arranged according to a square array pattern having N*N (N is equal to or greater than two) filter pixels.

[0025] In some embodiments, the first color may be green (G), the second color may be blue (B), and the third color may be red (R), or the second color may be red (R) and the third color may be blue (B).

[0026] In some embodiments, the square array pattern can have 3*3 filter pixels, including five filter pixels of the first color arranged at the center position and four corners of the unit, and four filter pixels of the second color or four filter pixels of the third color arranged at the left, right, top and bottom positions of the center position.

[0027] In some embodiments, the square array pattern can have 3*3 filter pixels, including five filter pixels of the second color or the third color arranged in the center position and four corners of the unit, and four filter pixels of the first color arranged at the left, right, top and bottom positions of the center position.

[0028] In some embodiments, the square array pattern can have 3*3 filter pixels, including five filter pixels of the first color arranged at the center position of the unit and at the left, right, top and bottom positions of the center position, and four filter pixels of the second color or four filter pixels of the third color arranged in the four corners. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and / or other aspects and advantages of the embodiments of the present disclosure will become apparent and more readily understood from the following description made with reference to the accompanying drawings, in which:

[0030] Figure 1 is an explanatory plan view of a first color filter according to a comparative example, showing a process of generating three color signals by interpolation of two colors;

[0031] Figure 2 is a block diagram schematically showing the overall arrangement of a color imaging system according to an embodiment of the present disclosure;

[0032] Figure 3A is an illustrative plan view of a first color filter for a 2*2 unit according to one embodiment of the present disclosure;

[0033] Figure 3B is an illustrative plan view of a unit included in a first color filter;

[0034] Figure 4A is an illustrative plan view of a second color filter for a 3*3 unit according to an embodiment of the present disclosure;

[0035] Figure 4B is an illustrative plan view of a unit included in the second color filter;

[0036] Figure 5 is an explanatory plan view of a first color filter or a second color filter according to a first embodiment of the present disclosure, showing a process for generating three color signals with long / short exposure and an interpolation process of two colors;

[0037] Figure 6 is an explanatory plan view of a first color filter or a second color filter, showing a long / short exposure interpolation process and an HDR synthesis process (long / short exposure fusion);

[0038] Figure 7is an illustrative plan view of sequentially reading pixel signals with long / short exposure from an image sensor using a line buffer.

[0039] Figure 8 is an explanatory plan view of a first color filter or a second color filter, showing a long / short exposure interpolation process and an HDR synthesis process (long / short exposure fusion);

[0040] Fig. 9A and Fig. 9B is an illustrative plan view of a filter having a Bayer arrangement;

[0041] Fig.10 is a flow chart illustrating a conventional method for generating an HDR image; and

[0042] Fig.11A and Fig. 11B is an illustrative plan view of two color filters for a 3*3 unit according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] Embodiments of the present disclosure will be described in detail, and examples of embodiments of the present disclosure will be illustrated in the accompanying drawings. Throughout the specification, identical or similar elements and elements having identical or similar functions are indicated by similar reference numerals. The embodiments described herein with reference to the accompanying drawings are illustrative, and their purpose is to illustrate the present disclosure, but should not be construed as limiting the present disclosure.

[0044] Before explaining a color imaging system according to an embodiment of the present disclosure, for comparison, a color imaging system according to a comparative example is explained, which has a color filter with a green (G) color for all units (2*2 units, i.e., one unit includes four filter pixels) and does not perform HDR synthesis processing.

[0045] Figure 1 Color filters of red (R) and blue (B), diagonal addition, and interpolation are illustrated.

[0046] The color filter includes a plurality of cells, more specifically, sixteen (=4*4) cells arranged in a horizontal direction at a first predetermined pitch and in a vertical direction at a second predetermined pitch.

[0047] The size of the unit of the color filter is the same as the size of the image sensor pixel of the image sensor (not shown). Each of the units of the color filter corresponds to each of the image sensor pixels. That is, the size of the unit of the color filter is the same as the size of the image sensor pixel of the image sensor. Each of the units of the color filter has N*N (N is equal to or greater than two; in this color filter, N is two) filter pixels, arranged in the horizontal direction at a third predetermined pitch and arranged in the vertical direction at a fourth predetermined pitch. As an example of this embodiment of the present disclosure, the color filter has 2*2 (N=2) filter pixels.

[0048] Another conventional system includes a dichroic prism and three image sensors. The three image sensors generate three color signals respectively, and interpolation is not required. Therefore, no aliasing signal is generated, and the color resolution is high. However, the configuration of this system is complicated, the size is increased, and the cost is extremely high.

[0049] Furthermore, in the color filter, each of the cells includes a color that mainly contributes to generating a luminance signal, specifically, each of the cells includes green (G), red (R), or blue (B), and green (G) is arranged in a checkerboard pattern.

[0050] Among the four cells, a green (G) color signal is generated for the 1 / 2 cell, a red (R) color signal is generated for the 1 / 4 cell, and a blue (B) color signal is generated for the 1 / 4 cell.

[0051] Each of the green (G) color signal, the red (R) color signal, and the blue (B) color signal is arranged on a diagonal line. The diagonal addition of the green (G) color signal is performed to obtain one unit including four filter pixels, the diagonal addition of the red (R) color signal is performed to obtain a 1 / 2 unit including two filter pixels, and the diagonal addition of the blue (B) color signal is performed to obtain a 1 / 2 unit including two filter pixels.

[0052] Interpolation is not performed on green (G), but is performed on red (R) and blue (B).

[0053] According to this comparative example, there is no need to perform interpolation on green (G) which mainly contributes to generating a brightness signal. Therefore, an aliasing signal generated due to interpolation of green (G) can be suppressed, thereby improving color resolution. However, an HDR image cannot be obtained through the above comparative example.

[0054] A color imaging system according to one embodiment of the present disclosure will be described below, which achieves both improved color resolution and HDR images.

[0055] Reference Figure 2, a color imaging system 1 according to an embodiment of the present disclosure includes an optical system 11 , an imaging device 12 including an image sensor and a color filter, and an image processing unit 13 .

[0056] The optical system 11 includes at least one optical lens, preferably includes a lens group including a plurality of optical lenses, an aperture adjustment mechanism, a zoom mechanism, and an autofocus mechanism.

[0057] The imaging device 12 includes an image sensor, such as a charge-coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) image sensor, which has a plurality of photoelectric conversion elements arranged in the horizontal direction and in the vertical direction, and a color filter arranged on the image sensor. The imaging device 12 receives light 21 from the optical system 11 and outputs color signals 22 of three colors of red (R), green (G) and blue (B).

[0058] The image processing unit 13 receives a color (R, G, and B) signal 22, performs several processes such as white balance 13a, diagonal addition 13b, long / short exposure interpolation 13c, HDR synthesis (long / short exposure fusion) 13d, and color correction 13e, and outputs a color image signal 23.

[0059] Figure 3A The first color filter CF1 is illustrated, Figure 3B One unit of the first color filter CF1 is shown. The first color filter CF1 is disposed on the image sensor.

[0060] The first color filter CF1 includes a plurality of cells, and more specifically, includes thirty-six (=6*6) cells arranged in a horizontal direction at a first predetermined pitch and in a vertical direction at a second predetermined pitch.

[0061] The size of the unit of the first color filter CF1 is the same as the size of the image sensor pixel of the image sensor. Each of the units of the first color filter CF1 corresponds to each of the image sensor pixels. Figure 3B As illustrated, each of the cells of the first color filter CF1 has N*N (N is equal to or greater than two) filter pixels arranged in the horizontal direction at a third predetermined pitch and in the vertical direction at a fourth predetermined pitch. Each of the image sensor pixels of the image sensor corresponds to four filter pixels of the first color filter CF1. As an example of this embodiment of the present disclosure, the first color filter CF1 has 2*2 (N=2) filter pixels.

[0062] In the first color filter CF1, each cell includes two filter pixels of a color mainly contributing to generation of a luminance signal, specifically, green (G), arranged in a checkerboard pattern, and includes two filter pixels of red (R) or blue (B).

[0063] In addition, each filter pixel is assigned with a long exposure or a short exposure. In the first color filter CF1, the same exposure is assigned to all four filter pixels included in each cell, and cells with long exposure and cells with short exposure are arranged in a checkerboard pattern, respectively.

[0064] Figure 4A The second color filter CF2 of one embodiment is illustrated, Figure 4B One unit of the second color filter CF2 is shown. The second color filter CF2 is disposed on the image sensor.

[0065] The second color filter CF2 includes a plurality of cells, and more specifically, includes sixteen (=4*4) cells arranged in a horizontal direction at a first predetermined pitch and in a vertical direction at a second predetermined pitch.

[0066] The size of the unit of the second color filter CF2 is the same as the size of the image sensor pixel of the image sensor. Each of the units of the second color filter CF2 corresponds to each of the image sensor pixels. Figure 4B As illustrated, each of the cells of the second color filter CF2 has 3*3 filter pixels arranged in the horizontal direction at a third predetermined pitch and in the vertical direction at a fourth predetermined pitch. Each of the image sensor pixels of the image sensor corresponds to nine filter pixels of the second color filter CF2.

[0067] In the second color filter CF2, each cell includes five filter pixels of a color mainly contributing to generation of a luminance signal, specifically green (G), arranged in a checkerboard pattern, and includes four filter pixels of red (R) or blue (B).

[0068] In addition, each filter pixel is assigned a long exposure or a short exposure. In the second color filter CF2, the cells whose green (G) filter pixels are assigned a long exposure and the cells whose green (G) filter pixels are assigned a short exposure are arranged alternately in a checkerboard pattern, the cells whose red (R) filter pixels are assigned a long exposure and the cells whose red (R) filter pixels are assigned a short exposure are arranged alternately in a checkerboard pattern, and the cells whose blue (B) filter pixels are assigned a long exposure and the cells whose blue (B) filter pixels are assigned a short exposure are arranged alternately in a checkerboard pattern.

[0069] The processing performed by the image processing unit 13 is described in detail below.

[0070] like Figure 5 As illustrated, the image processing unit receives color (R, G, and B) signals 22 output from an image sensor having a first color filter or a second color filter thereon, and performs diagonal pixel addition.

[0071] As a result of the above-mentioned diagonal pixel addition, units with long exposure of green (G) color signals and short exposure of green (G) color signals arranged alternately in a checkerboard pattern are obtained, units with long exposure of red (R) color signals, short exposure of red (R) color signals and units without red (R) color signals arranged alternately in a checkerboard pattern are obtained, and units with long exposure of blue (B) color signals, short exposure of blue (B) color signals and units without blue (B) color signals arranged alternately in a checkerboard pattern are obtained.

[0072] like Figure 6 As illustrated, interpolation of long exposure and short exposure is performed on a green (G) color signal, a red (R) color signal, and a blue (B) color signal.

[0073] By performing interpolation of long exposure and short exposure, green (G) color signals with long exposure for all frames, green (G) color signals with short exposure for all frames, red (R) color signals with long exposure for all frames, red (R) color signals with short exposure for all frames, blue (B) color signals with long exposure for all frames, and blue (B) color signals with short exposure for all frames are obtained.

[0074] HDR synthesis is performed on a green (G) color signal with long exposure, a green (G) color signal with short exposure, a red (R) color signal with long exposure, a red (R) color signal with short exposure, a blue (B) color signal with long exposure, and a blue (B) color signal with short exposure, that is, addition of a green (G) color signal with long exposure and a green (G) color signal with short exposure, addition of a red (R) color signal with long exposure and a red (R) color signal with short exposure, and addition of a blue (B) color signal with long exposure and a blue (B) color signal with short exposure.

[0075] As a result, a green (G) image frame with long / short exposure fusion, a red (R) image frame with long / short exposure fusion, and a blue (B) image frame with long / short exposure fusion are obtained. Finally, a color image frame with long / short exposure fusion is obtained.

[0076] Reading green (G), red (R), and blue (B) color signals from the image sensor is performed as follows.

[0077] according to Figure 7 In the illustrated sequence, a long exposure green (G) signal and a short exposure green (G) signal in one row are alternately output at each clock (T), and a long exposure blue (B) signal and a short exposure red (R) signal in one row are alternately output.

[0078] When reading the color signal, a line buffer having a capacity to store a line of color signals is used. It is not necessary to use a frame memory having a capacity to store all color signals of one image frame, because interpolation and HDR synthesis performed after reading the color signal can be performed using a line of green color signals and a line of red (R) and blue (B) signals.

[0079] like Figure 8 As illustrated, as a result of performing interpolation of the long / short exposure image on the short exposure and long exposure green (G) signals stored in the line buffer, a long exposure green (G) signal in one image frame and a short exposure green (G) signal in the line buffer are generated.

[0080] Similar to the green (G) color signal, as a result of performing interpolation of the long / short exposure image on the long exposure red (R) signal, the short exposure blue (B) signal, the long exposure blue (B) signal, and the short exposure red (R) signal stored in the line buffer, a long exposure red (R) signal in one image frame, a short exposure red (R) signal in one image frame, a long exposure blue (B) signal in one image frame, and a short exposure blue (B) signal in one image frame are obtained.

[0081] As a result of performing HDR synthesis on the green (G) color signal of long exposure and short exposure, the red (R) color signal of long exposure and short exposure, and the blue (B) color signal of long exposure and short exposure, a long / short exposure fused green (G) color signal, a long / short exposure fused red (R) color signal, and a long / short exposure fused blue (B) color signal are obtained. Finally, the image processing unit 13 generates a color (green (G), red (R), and blue (B)) image signal of one frame.

[0082] The above-described embodiments of the present disclosure provide the following technical effects.

[0083] Since all cells include green (G), which primarily contributes to the generation of the luminance signal, high color resolution can be achieved. Fig. 9A and Fig. 9B The Bayer arrangement shown is similar, with two green (G) filter pixels being included in a 2*2 unit and five green (B) filter pixels being included in a 3*3 unit.

[0084] More specifically, if Figure 5 and Figure 6 As shown, a long-exposure green (G) color signal and a short-exposure green (G) color signal of all filter pixels included in one frame are obtained, which are different from the red (R) and blue (B) color signals. Therefore, there is no resolution loss compared to the Bayer arrangement.

[0085] Fig.10 The invention illustrates a "multi-frame fusion" method for generating an HDR image. According to the method, long-exposure first image data and short-exposure second image data of one frame are added to generate a long / short-exposure fused final image data.

[0086] This method requires a frame memory having a capacity to store image data for one frame, which imposes a considerable burden on hardware.

[0087] Furthermore, the image sensor needs to be driven at a double frame rate, which requires a large bandwidth of the memory bus.

[0088] Therefore, this method consumes costs.

[0089] In contrast, according to the above embodiment of the present invention, a frame memory is not required, and a line buffer having a capacity much smaller than that of the frame memory can be used to read a color signal. In addition, driving an image sensor does not require a double frame rate.

[0090] Therefore, the embodiments of the present disclosure achieve high color resolution and HDR images at a low cost.

[0091] Although embodiments of the present disclosure have been shown and described, those skilled in the art will appreciate that the embodiments are illustrative and are not to be construed as limiting the present disclosure, and that changes, modifications, substitutions, and variations may be made in the embodiments without departing from the scope of the present disclosure.

[0092] In the above embodiments of the present disclosure, the Figure 3A and Figure 3B The first color filter (2*2 units) and Figure 4A and Figure 4B The second color filter (3*3 unit) is shown. However, the configuration of the color filter is not limited to these first color filters and second color filters.

[0093] In the first color filter of 2*2 units, all units include two green (G) filter pixels, and the remaining two filter pixels are red (R) or blue (B). In the second color filter of 3*3 units, all units include five green (G) filter pixels, and the remaining four filter pixels are red (R) or blue (B). However, it is necessary to include at least one green (G) filter pixel and the remaining filter pixels of red (R) or blue (B) in each unit.

[0094] For example, Fig.11A and Fig. 11B Two examples of color filters of 3*3 units are illustrated.

[0095] The color filters include sixteen (=4*4) cells arranged in the horizontal direction at a first predetermined pitch and in the vertical direction at a second predetermined pitch.

[0096] like Fig.11A As shown, in the second color filter CF11, five filter pixels of red (R) or blue (B) are arranged at the center position and four corners of the unit. Four filter pixels of green (G) are arranged on the left and right sides and on the upper and lower sides of the center position.

[0097] When five red (R) filter pixels are arranged in a specific cell at the center position and four corners, five blue (B) filter pixels are arranged in the center position and four corners in two or four cells adjacent to the specific cell. When five blue (B) filter pixels are arranged in a specific cell at the center position and four corners, five red (R) filter pixels are arranged in the center position and four corners in two or four cells adjacent to the cell. Such a block of sixteen (=4*4) cells is arranged in a predetermined array pattern, particularly in a matrix pattern, such as Figure 7 B. Each filter pixel is assigned a long exposure or a short exposure, Figure 5 The filters shown are similar.

[0098] Reference Fig. 11B The third color filter CF12 has the same Fig.11A The color filter shown has different color (R), (G) and (B) array patterns. In this color filter, five green (G) filter pixels are arranged in the center position of the unit and in the left, right, upper and lower positions of the center position. Four filter pixels of red (R) or blue (B) are arranged in the four corners.

[0099] When four red (R) filter pixels are arranged in a specific cell in four corners, four blue (B) filter pixels are arranged in four corners in two or four cells adjacent to the specific cell. When four blue (B) filter pixels are arranged in a specific cell in four corners, four red (R) filter pixels are arranged in four corners in two or four cells adjacent to the specific cell. Such a block of sixteen (=4*4) cells is arranged in a predetermined array pattern, in particular, in a matrix pattern, such as Fig. 11B Each filter pixel is assigned a long exposure or a short exposure, Figure 5 The filters shown are similar.

[0100] In the description of the embodiments of the present disclosure, it should be understood that terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" should be interpreted as referring to the direction or position shown in the described or discussed drawings. These relative terms are only used to simplify the description of the present disclosure and do not indicate or imply that the mentioned device or element must have a specific orientation, or be constructed or operated in a specific orientation. Therefore, these terms cannot be interpreted as limiting the present disclosure.

[0101] In addition, terms such as "first" and "second" are used herein for descriptive purposes and are not intended to indicate or imply relative importance or significance, or to imply the number of technical features indicated. Therefore, features defined with "first" and "second" may include one or more of such features. In the description of the present disclosure, "plurality" means two or more than two, unless otherwise specified.

[0102] In the description of the embodiments of the present disclosure, unless otherwise specified or limited, the terms "installation", "connection", "coupling", etc. are widely used and can be understood by those skilled in the art according to the specific circumstances, such as a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical or electrical connection; it can also be a direct connection or an indirect connection via an intermediate structure; it can also be an internal communication between two elements.

[0103] In the embodiments of the present disclosure, unless otherwise specified or limited, the structure of the first feature being "on" or "below" the second feature may include an embodiment in which the first feature is in direct contact with the second feature, and may also include an embodiment in which the first feature and the second feature are not in direct contact with each other but are in contact via an additional feature formed between them. In addition, the first feature being "on", "above" or "on the top" of the second feature may include an embodiment in which the first feature is directly "on", "above" or "on the top" of the second feature, or obliquely "on", "above" or "on the top", or simply means that the first feature is located at a higher height than the second feature; and the first feature being "below", "below" or "below" of the second feature may include an embodiment in which the first feature is directly "below", "below" or "below" of the second feature, or obliquely "below", "below" or "below", or simply means that the first feature is located at a lower height than the second feature.

[0104] Various embodiments and examples are provided in the above description to implement different structures of the present disclosure. In order to simplify the present disclosure, certain elements and settings are described above. However, these elements and settings are only used as examples and are not intended to limit the present disclosure. In addition, the numbers and / or letters of the figure marks may be repeated in different examples of the present disclosure. This repetition is for simplification and clarity and does not involve the relationship between different embodiments and / or settings. In addition, examples of different processes and materials are provided in the present disclosure. However, those skilled in the art will appreciate that other processes and / or materials may also be applied.

[0105] References throughout this specification to "one embodiment," "some embodiments," and "an exemplary embodiment," "an example," "a specific example," or "some examples" mean that a particular feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearance of the above phrases throughout this specification does not necessarily refer to the same embodiment or example of the present disclosure. Furthermore, in one or more embodiments or examples, the particular features, structures, materials, or characteristics may be combined in any suitable manner.

Claims

1. A color imaging system, comprising: an image sensor comprising a plurality of image sensor pixels and outputting a first color signal, a second color signal, and a third color signal; a color filter disposed on the plurality of image sensor pixels of the image sensor; and an image processing unit that receives the first color signal, the second color signal, and the third color signal from the image sensor, performs predetermined processing on the first color signal, the second color signal, and the third color signal, and outputs a color image signal, wherein the color filter comprises a plurality of cells, each of the cells corresponds to an image sensor pixel of the image sensor and each of the cells comprises a plurality of filter pixels, and wherein all cells comprise at least one filter pixel of a first color that primarily contributes to generating a brightness signal, the remaining filter pixels of the cells are of the second color or the third color, and each of the filter pixels is assigned a long exposure or a short exposure, wherein the first color is green (G), the second color is blue (B) and the third color is red (R), or the second color is red (R) and the third color is blue (B), The image sensor sequentially outputs the first color signal, the second color signal, and the third color signal using a line buffer with long exposure or short exposure, The image processing unit performs pixel addition on the second color signal and the third color signal, performs long exposure and short exposure interpolation on the first color signal with long exposure and with short exposure, the second color signal with long exposure and with short exposure, and the third color signal with long exposure and with short exposure, and performs HDR synthesis on the first color signal with long exposure and with short exposure, the second color signal with long exposure and with short exposure, and the third color signal with long exposure and with short exposure to generate an HDR color image signal.

2. The color imaging system according to claim 1, wherein: All filter pixels of the first color included in each cell are assigned the same exposure of the long exposure or the short exposure, and the filter pixels of the first color are assigned the long exposure or the short exposure alternately along rows or columns on a cell-by-cell basis.

3. The color imaging system according to claim 1 or 2, wherein: all filter pixels of the second color included in each cell are assigned the same exposure of the long exposure or the short exposure, and all filter pixels of the third color included in each cell are assigned the same exposure of the long exposure or the short exposure, All filter pixels of the second color included in the cells along the rows or columns are assigned the same exposure of the long exposure or the short exposure, and the filter pixels of the second color are assigned the long exposure or the short exposure alternately row by row or column by column, and all filter pixels of the third color included in the cells along the rows or columns are assigned the same exposure of the long exposure or the short exposure, and the filter pixels of the third color are assigned the long exposure or the short exposure alternately row by row or column.

4. The color imaging system according to claim 3, wherein: Cells along rows or columns including all filter pixels of the second color assigned with long exposure or short exposure and cells along the same rows or columns including all filter pixels of the third color assigned with short exposure or long exposure are alternately arranged.

5. The color imaging system according to claim 1 or 2, wherein: sequentially outputting the first color signal of long exposure and the first color signal of short exposure from the image sensor using the line buffer, The second color signal of long exposure and the third color signal of short exposure, or the second color signal of short exposure and the third color signal of long exposure are sequentially output from the image sensor using the line buffer.

6. The color imaging system according to claim 5, wherein: performing interpolation of long exposure and short exposure on the first color signal of long exposure and the first color signal of short exposure stored in the line buffer to generate the first color signal of long exposure in one frame and the first color signal of short exposure in one frame, Interpolation of long exposure and short exposure is performed on the second color signal of long exposure, the third color signal of short exposure, the second color signal of short exposure, and the third color signal of long exposure stored in the line buffer to generate the second color signal of long exposure in one frame, the second color signal of short exposure in one frame, the third color signal of long exposure in one frame, and the third color signal of short exposure in one frame.

7. The color imaging system according to claim 1 or 6, wherein: Each of the cells of the color filter includes filter pixels arranged according to a square array pattern having N*N (N is equal to or greater than two) filter pixels.

8. The color imaging system according to claim 7, wherein: The square array pattern has 3*3 filter pixels, including five filter pixels of the first color arranged at the center position and four corners of the unit, and four filter pixels of the second color or four filter pixels of the third color arranged at the left, right, top and bottom positions of the center position.

9. The color imaging system according to claim 7, wherein: The square array pattern has 3*3 filter pixels, including five filter pixels of the second color or the third color arranged at the center position and four corners of the unit, and four filter pixels of the first color arranged at the left, right, top and bottom positions of the center position.

10. The color imaging system according to claim 7, wherein: The square array pattern has 3*3 filter pixels, including five filter pixels of the first color arranged at the center position of the unit and at the left, right, top and bottom positions of the center position, and four filter pixels of the second color or four filter pixels of the third color arranged in the four corners.

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