Image generating apparatus and method

An image generating method of an image generating apparatus is provided. The method includes displaying a live view image on a screen of an image generating apparatus, comparing a shutter speed with a frame rate of the live view image when there is a command to image a still image during the displaying of the live view image, adding current frame data of the live view image to next frame data of the live view image to generate added next frame data when the shutter speed is smaller than the frame rate of the live view image, and reading out the added next frame data of the live view image to generate the still image.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 from Korean Patent Application No. 10-2013-0071815, filed on Jun. 21, 2013, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Apparatuses and methods consistent with exemplary embodiments of the present general inventive concept relate to an image generating apparatus and method, and more particularly, to an image generating apparatus and method, capable of reducing noise when a still image is generated from a live view image.

2. Description of the Related Art

Most of digital cameras or smart phones developed in recent years provide an electrical view finder configured to let a user check a subject and a captured image with a naked eye. In capturing an image, the electrical view finder processes image information detected in an image sensor and displays a live view image. When the user operates a shutter, electronic apparatuses generate a still image corresponding to the live view image at a point of time when the shutter is operated.

Some electronic apparatuses provide a continuous shooting function configured to continuously capture a subject in preset time units and acquire pieces of still images. Since large amounts of data are required to perform the continuous shooting function, system performance of above a certain level is required to display a live view image while a series of still images output by the continuous shooting are processed.

As one method of solving the problem, technology to generate a still image by generating a live view image using only a portion of an image sensor, and combining the portion of the image sensor and the remainder of the image sensor in continuous shooting is suggested.FIG. 1illustrates the above-described method.

That is,FIG. 1is a schematic diagram illustrating technology to divide an image sensor to perform continuous shooting.

As illustrated inFIG. 1, the image sensor is configured of a plurality of pixels (total pixels10). The total pixels10are divided into a first pixel group11configured to generate a live view image and a second pixel group12configured to generate a still image. The second pixel group12is configured of remaining pixels among total pixels10other than pixels constituting the first pixel group11. For example, as illustrated inFIG. 1, the first pixel group11may include a red (R) pixel having coordinates (0,0), a green-red (Gr) pixel having coordinates (0,3), a green-blue (Gb) pixel having coordinates (3,0), and a blue (B) pixel having coordinates (3,3), and the second pixel group12may include the remaining pixels other than the pixels included in the first pixel group11.

Live view image display is performed by processing data of the first pixel group11. When there is a continuous shooting command, a still image having full resolution is generated by combining the first pixel group11and the second pixel group12. When shutter speed, which may also be referred to as a frame rate of the still image, is smaller than a frame rate of a live view image, the above-described process is performed by adding an additional frame of the live view image, corresponding to the shutter speed. For example, when the shutter speed is ½ of the frame rate of the live view image, the second pixel group12of two pieces of continuous frames of the live view image is used to generate the still image.

The technology to independently generate the still image using only portions of pixel values of an image sensor while continuously providing the live view image promotes convenience of a user.

However, as described above, when the shutter speed is smaller than the frame rate of the live view image, since exposure data of the image sensor has to be read out plural times to generate one piece of still image, noise generated in the read-out process is increased. Therefore, there is a need for a method to reduce the read-out noise in the technology.

SUMMARY OF THE INVENTION

One or more exemplary embodiments of the present general inventive concept provide an image generating apparatus and method, which are capable of minimizing noise generated in a plurality of read-out processes for exposure data of an image sensor to generate a still image when a shutter speed is different from a frame rate of a live view image.

Exemplary embodiments of the present general inventive concept provide an image generating method. The method may include displaying a live view image on a screen of an image generating apparatus, comparing a shutter speed with a frame rate of the live view image when there is a command to image a still image during the displaying of the live view image, adding current frame data of the live view image to next frame data of the live view image to generate added next frame data when the shutter speed is smaller than the frame rate of the live view image, and reading out the added next frame data of the live view image to generate the still image.

The adding of the current frame data of the live view image to the next frame data of the live view image may include adding the current frame data of the live view image to the next frame data of the live view image without resetting the current frame data of the live view image.

The method may further include forming a potential of a direction of a photodiode by applying a bias voltage to current frame data of the live view image, and generating the next frame data to which the current frame data of the live view image is added through the photodiode.

The method may further include, when the command to image the still image is received during the displaying of the live view image, outputting first data from a first pixel group of an image sensor, and storing the first data. The frame data of the live view image may be based on data output from a second pixel group of the image sensor distinct from the first pixel group.

The generating of the still image may include generating a final still image by combining the stored first data and the read out added next frame data of the live view image.

The method may further include subtracting the current frame data of the live view image from the next frame data of the live view image, to which the current frame data of the live view image is added, to generate a next image frame of the live view image when the shutter speed is smaller than the frame rate of the live view image.

The method may further include displaying the generated next image frame of the live view image.

The method may further include generating the still image based on the current frame data of the live view image when the shutter speed is equal to or larger than the frame rate of the live view image.

Exemplary embodiments of the present general inventive concept also provide an image generating apparatus. The image generating apparatus may include a display configured to display a live view image, a frame rate comparator configured to compare a shutter speed with a frame rate of the live view image when there is a command to image a still image during displaying of the live view image, and a controller configured to add current frame data of the live view image to next frame data of the live view image when the shutter speed is smaller than the frame rate of the live view image, and to read out the next frame data of the live view image, to which the current frame data of the live view image is added, to generate the still image.

The controller may add the current frame data of the live view image to the next frame data of the live view image without resetting the current frame data of the live view image.

The controller may form a potential of a direction of a photodiode by applying a bias voltage to the current frame data of the live view image, and generate the next frame data to which the current frame data of the live view image is added through the photodiode.

The controller may output first data from a first pixel group of an image sensor and store the first data when the command to image the still image is received during the displaying of the live view image, and the frame data of the live view image may be based on data output from a second pixel group of the image sensor distinct from the first pixel group.

The controller may generate a final still image by combining the stored first data and the read out next frame data of the live view image.

The controller may subtract the current frame data of the live view image from the next frame data of the live view image, to which the current frame data of the live view image is added, to generate a next image frame of the live view image when the shutter speed is smaller than the frame rate of the live view image.

The controller may control the generated next image frame of the live view image to be displayed.

The controller may generate the still image based on the current frame data of the live view image when the shutter speed is equal to or larger than the frame rate of the live view image.

The image generating apparatus may be at least one among a smart phone, a cellular phone, a digital camera, an MPEG Audio Layer 3 (MP3), a portable multimedia player (PMP), a tablet personal computer (PC), a laptop computer, smart glasses, and a smart watch.

A non-transitory computer-readable recording medium may contain computer-readable codes as a program to execute the image generating method.

Exemplary embodiments of the present general inventive concept also provide an image generating method, the method including displaying a live view image, receiving an input to perform a shutter operation to image a still image during the displaying of the live view image, obtaining current frame data of the live view image at an image sensor, if a shutter speed is smaller than a frame rate of the live view image, obtaining next frame data of the live view image at the image sensor, the next frame data being combined with the current frame data in the image sensor to generate added next frame data in the image sensor, and reading out the added next frame data of the live view image from the image sensor to generate a still image.

Exemplary embodiments of the present general inventive concept also provide an image generating apparatus including a display configured to display a live view image, an image sensor to obtain frame data of the live view image, and a controller configured to receive an input to perform a shutter operation to image a still image during displaying of the live view image, to control the image sensor to add current frame data of the live view image to next frame data of the live view image to generate added next frame data of the live view image in the image sensor when the shutter speed is smaller than the frame rate of the live view image, and to read out the added next frame data of the live view image to generate a still image.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The matters defined in the following description, such as detailed construction and elements, are provided to assist in a comprehensive understanding of the exemplary embodiments of the present general inventive concept. Thus, it is apparent that the exemplary embodiments can be carried out without those specifically defined matters. Also, functions or elements known in the related art are not described in detail since they would obscure the exemplary embodiments with unnecessary detail.

FIG. 2is a block diagram illustrating a configuration of an image generating apparatus100according to an exemplary embodiment of the present general inventive concept.

Referring toFIG. 2, an image generating apparatus100according to an exemplary embodiment of the present general inventive concept includes a display110, a frame rate comparator120, and a controller130.

The image generating apparatus100according to an exemplary embodiment of the present general inventive concept may be various electronic apparatuses including an image imaging function. For example, the image generating apparatus100may be implemented as any one among a digital camera, a smart phone, a cellular phone, an MPEG Audio Layer 3(MP3), a portable multimedia player (PMP), a tablet PC, a laptop computer, smart glasses, and a smart watch.

For the purposes of the present general inventive concept, “imaging” an image corresponds to capturing, photographing, generating, storing, and/or transmitting an image, for example with a camera.

The display110is configured to display a live view image or display an imaged still image. The display110may perform an electrical view finder function of the image generating apparatus100.

When the image generating apparatus100enters an imaging mode, the display110images a subject, processes the imaged image in real time, and displays the imaged image as a live view image. As described above, the display110may generate the live view image using preset portions of pixels10of an image sensor. Even when there is a shutter operation, the display110continuously displays the live view image. The technology will be described in detail later.

The display110may be implemented with various techniques. For example, the display110may be implemented with various display techniques, such as an organic light emitting diode (OLED), a liquid crystal display (LCD), a plasma display panel (PDP), a vacuum fluorescent display (VFD), a field emission display (FED), or an electroluminescence display (ELD).

The display110may include a touch screen. At this time, the display110displays various user interfaces. When there is a touch input of a user for the displayed user interface, the display generates a control command corresponding to the touch input of the user to operate the image generating apparatus100. A shutter configured to generate a still image may be provided as the displayed user interface, and at this time, the user may touch (press) the displayed shutter to input a shutter operation command to the image generating apparatus100.

The image generating apparatus100includes the frame rate comparator120. The frame rate comparator120is configured to compare shutter speed with a frame rate of the live view image when there is a shutter operation to image a still image during the displaying of the live view image.

The frame rate comparator120may be loaded into a memory in an operating system or an application form to perform the above described operation. Alternatively, the frame rate comparator120may be provided as a hardware chip (not illustrated), such as an embedded chip.

The controller130may control an overall operation of the image generating apparatus100. Specifically, the controller130adds current frame data of a live view image to next frame data of the live view image when shutter speed is smaller than a frame rate of the live view image as a comparison result. The controller130may control to read out the next frame data of the live view image, to which the current frame data of the live view image is added, and to generate a still image.

The controller130controls an overall operation of an image generating apparatus. The controller130includes a hardware configuration such as a central processing unit (CPU) (not illustrated) or a cache memory, and a software configuration of an operating system or an application configured to perform a specific purpose. The controller130reads out a control command for each component configured to perform the operation described above or an operation to be described later according to a system clock (not illustrated) from a memory, and generates an electrical signal according to the read out control command to operate the hardware components. Further, the controller130may include a circuit configuration according to an exemplary embodiment of the present general inventive concept to be described later.

Hereinafter, the above-described exemplary embodiment of the present general inventive concept will be described in detail.

FIG. 3is a schematic diagram illustrating a still image generating method of an image generating apparatus100according to an exemplary embodiment of the present general inventive concept.

An image capturing unit (not illustrated) of the image generating apparatus100,100-1includes a shutter (not illustrated), a lens unit (not illustrated), an iris (not illustrated), and an image sensor such as a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. The shutter and iris adjust an amount of light, and the CCD or CMOS image sensor accumulates the light through a photodiode PD of a pixel array115, and output an electrical signal according to the amount of accumulated light. A color filter array (CFA) may be used to acquire a color image. The CFA passes through only light representing one color every one pixel and has a regular arrangement structure, and the CFA has various types according to the arrangement structure. The lens unit may include a zoom lens configured to magnify or reduce a size of a subject and a focus lens configured to adjust a focus of the object.

The output electrical signal is converted into a digital signal through an analog-digital converter (hereinafter referred to as ADC)110. Processing for a still image and processing for a live view image are separately performed.

FIG. 4is a view illustrating an image sensor circuit101according to an exemplary embodiment of the present general inventive concept,FIG. 5Ais a timing diagram of a configuration of the image sensor circuit101illustrated inFIG. 4, andFIG. 5Bis a potential diagram of the configuration of the image sensor circuit101illustrated inFIG. 4.

The above-described process will be described in detail with reference toFIGS. 4 to 5B.

As illustrated inFIG. 4, the image sensor circuit101includes a photodiode PD, a transfer transistor TX, a reset transistor RX, and a floating diffusion node FD. The photodiode PD generates photo charges corresponding to an optical image of a subject and accumulates the generated photo charges. The transfer transistor TX transfers the photo charges generated in the photodiode PD to the floating diffusion node FD in response to a transfer signal. The reset transistor RX discharges the charges stored in the floating diffusion node FD in response to a reset signal. Before the reset signal is applied, the charges stored in the floating diffusion node FD are output, and in a correlated double sampling (CDS) image sensor, CDS processing is performed.

Referring toFIGS. 5A and 5B, an exposure for the photodiode PD is performed in a period in which the transfer of the transfer transistor TX is not performed. The photodiode PD generates photo charges corresponding to an optical image of a subject. When the reset transistor RX performs a reset operation in a first stage (1), as illustrated inFIG. 5Bthere is almost no potential barrier between the floating diffusion node FD and a power supply VDD_pix, and charges stored in the floating diffusion node FD are therefore discharged. However, since the transfer transistor TX does not allow charges to be transferred in the first stage, a potential barrier exists between the photodiode PD and the floating diffusion node FD in the first stage, and so no charges are transferred between the photodiode PD and the floating diffusion node FD.

In a second stage (2), the charge transfer as well as the reset operation is not performed, and charge accumulation of the photodiode PD is continuously performed. Unlike in the first stage, the reset operation is not performed, and so a potential barrier exists between the floating diffusion node FD and the power supply VDD_pix, blocking the transfer of charges therebetween.

A third stage (3) is a charge transfer stage. That is, the transfer transistor TX transfers the photo charges generated in the photodiode PD to the floating diffusion node FD in response to the transfer signal, and the floating diffusion node FD stores the charges.

In a fourth stage (4), the transfer transistor TX stops the transfer, and the charges stored in the floating diffusion node FD are output (read out). In a CDS image sensor, CDS processing is performed. The ADC110converts a CDS-processed analog signal into a digital signal. In a fifth stage (5) following the fourth stage, a reset operation is performed. In the exemplary embodiment of the present general inventive concept illustrated inFIGS. 5A-5B, the fifth stage is identical to the first stage, in that the reset operation is performed.

The charges accumulated through the first to fourth stages are read out to acquire raw data for image generation. In an exemplary embodiment of the present general inventive concept, the still image and the live view image are generated by reading out different image pixels. That is, live view image data is generated using read-out data (hereinafter, referred to as first data) for a first pixel group310among total image pixels10, and a still image is generated by combining read-out data (second data) for a second pixel group320other than the first pixel group310and the read-out data (the first data) for the first pixel group310. As a result, the still image is generated using pixel data of a full size.

At this time, a method of reading out one pixel among total pixels and skipping two pixels to generate a live view image may be defined as a 1R2S method. Similarly, data of the first pixel group310may be read out using a 2R2S method, a 1R4S method, or a 2R4S method.

With reference toFIG. 3, the first data and the second data are read out at150and116, respectively corresponding to live view mode readout and still mode readout. The first and second data are then output through sensor interfaces (SSIFs)155and120, respectively corresponding to the live view mode and the still mode. The image processors (not illustrated) performs image pre-processing on the respective output image data (pre-processing illustrated inFIG. 3at160,125). For example, the image processors eliminate a black level due to a dark current generated in a CCD image sensor and a CFA filter sensitive to temperature change. The image processors may perform gamma correction for encoding information according to nonlinearity of a human vision system. The image processor may perform CFA interpolation to interpolate a Bayer pattern implemented in a RGRG line and a GBGB line of gamma-corrected predetermined data in a RGB line. The image processor converts the interpolated RGB signal into a YUV signal, performs an edge compensation to sharply process an image by filtering a Y signal by a high-pass filter and color correction to correct a U signal and a V signal using a standard color coordinate system, and removes noise of the YUV signal.

The first data is subject to IPC_M for moving image processing (165) to be output in a live view image. The second data is subject to IPC_S for still image processing (130) to be stored in a memory140, for example an SD card. The first data stored in a buffer (145) is combined with the second data and the above-described image pre-processing125is performed when there is a still image generation command.

It is considered that a user operates a shutter to image a still image. When shutter speed is equal to or larger than a frame rate of a live view image, still image data may be generated by combining the first data for live view image generation and the second data read out simultaneously with the first data. In the exemplary embodiment of the present general inventive concept, it is assumed that an exposure starting time of the photodiode PD is synchronized between still image generation and live view image generation. The assumption may be applied to exemplary embodiments of the present general inventive concept to be described below.

For example, it is assumed that the frame rate of the live view image is 1/60 second, and the shutter speed is 1/60 second. When a continuous shooting command is input at a time t0, the controller130exposes the first pixel group310and the second pixel group320to light for 1/60 second from the time t0to read out the first data of one frame and the second data of one frame, and signal-processes the read out first data and second data to generate a still image of one frame. At this time, there is no difference in the number of read-outs for still image generation as compared in live view image display.

However, when the shutter speed is less than the frame rate of the live view image, the number of read-outs is slightly different. The controller130has to generate still image data by adding the first data of a plurality of frames acquired in the same time as the exposure time of the second pixel group320to acquire the second data.

When the frame rate of the live view image is 1/60 second, and the shutter speed is 1/30 second, the controller130exposes the second pixel group320to light for 1/30 second from the time t0to read out second data of one frame when a continuous shooting command is input at the time t0. The controller130has to combine data, in which first data of a frame acquired by exposing the first pixel group310to light from 1/60 second from the time t0(hereinafter, referred to as first-first data), is added to the first data of a frame acquired by exposing the first pixel group310to light for the next 1/60 second (hereinafter, referred to as first-second data), is combined with the second data.

However, as described above, noise is generated in the process of reading out the charges stored in the floating diffusion node FD. When the shutter speed is smaller than the frame rate of the live view image, since the first data has to be read out twice as described above, an amount of noise is increased. Therefore, it is necessary to reduce the number of read-outs so as to remove the noise.

As described above, in the exemplary embodiment of the present general inventive concept, a method of reducing the number of read-outs is suggested. That is, when there is a shutter operation to image a still image during live view image display, the frame rate comparator120compares the shutter speed with the frame rate of the live view image. When it is determined that the shutter frame is smaller than the frame rate of the live view image, the controller130adds current frame data of the live view image to next frame data of the live view image, and generates a still image using the next frame data to which the current frame data of the live view image is added. Hereinafter, the still image generating operation will be described in detail.

FIG. 6is a view illustrating an image sensor circuit102according to an exemplary embodiment of the present general inventive concept,FIG. 7Ais a timing diagram of a configuration of the image sensor circuit102illustrated inFIG. 6, andFIG. 7Ais a potential diagram of the configuration of the image sensor circuit102illustrated inFIG. 6.

As illustrated inFIG. 6, an image sensor circuit102according to an exemplary embodiment of the present general inventive concept basically has the similar configuration to the image sensor circuit102illustrated inFIG. 4. That is, the image sensor circuit102includes a photodiode PD, a transfer transistor TX, a reset transistor RX, and a floating diffusion node FD. However, the image sensor circuit102illustrated inFIG. 6further includes a circuit configuration configured to form a reverse potential between the photodiode PD and the floating diffusion node FD. In an exemplary embodiment of the present general inventive concept, the circuit configuration may be a configuration configured to apply a bias voltage (“bias”) as illustrated inFIG. 6. That is, the bias voltage is applied (or is not applied) from outside the image sensor circuit102, and thus a potential barrier between the photodiode FD and the floating diffusion node (FD) may be eliminated even when the transfer transistor TX stops the transfer, and a reverse potential may be formed.

Referring toFIGS. 7A and 7B, a circuit operation when the frame rate comparator120determines that shutter speed is smaller than a frame rate of a live view image will be described.

As illustrated inFIGS. 7A and 7B, an exposure for the photodiode PD is performed in a period in which the transfer of the transfer transistor TX is not performed. Stages to be described later are set based on the frame rate of the live view image. That is, the first to fourth stages are the same as a cycle in which the first data to generate one image frame constituting the live view image is read out. The photodiode PD generates photo charges corresponding to an optical image of a subject. When the reset transistor RX performs a reset operation in the first stage (1), as illustrated inFIG. 7Bthere is almost no potential barrier between the floating diffusion node FD and a power supply VDD_pix, and charges stored in the floating diffusion node FD are therefore discharged. However, since the transfer transistor TX does not allow charges to be transferred in the first stage, a potential barrier exists between the photodiode PD and the floating diffusion node FD in the first stage, and so no charges are transferred between the photodiode PD and the floating diffusion node FD. It can be seen inFIGS. 7A and 7Bthat in the first stage, a bias voltage is applied, but the potential barrier exists as it is. That is, in the exemplary embodiment of the present general inventive concept illustrated inFIGS. 7A and 7B, since the potential barrier is maintained when the bias voltage is applied, and the potential barrier is collapsed when the bias voltage is interrupted, the bias is determined as a reverse bias.

In the second stage (2), the charge transfer as well as the reset operation is not performed, and charge accumulation of the photodiode PD is continuously performed. Unlike in the first stage, since the reset operation is not performed, a potential barrier exists between the floating diffusion node FD and the power supply VDD_pix, blocking the transfer of charges therebetween.

A third stage (3) is a charge transfer stage. That is, the transfer transistor TX transfers the photo charges generated in the photodiode PD to the floating diffusion node FD in response to a transfer signal, and the floating diffusion node FD stores the charges.

In a fourth stage (4), the transfer transistor TX stops the transfer, and the charges stored in the floating diffusion node FD are output (read-out of the first-first data). The output charges are used to generate a live view image. However, when there is a still image generation input, the first-first data is not used to generate the still image at this point. A process after a fifth stage (5) is performed to read out data for still image generation. Further, the reset transistor RX does not reset the charges stored in the floating diffusion node FD.

In the fifth stage, the potential barrier between the photodiode PD and the floating diffusion node FD is collapsed due to a bias voltage (the bias voltage may be a forward bias or a reverse bias). However, in a sixth stage (6), only after the transfer transistor TX forms a charge transfer path, charges are transferred. The photodiode PD adds photo charges transferred from the floating diffusion node FD to photo charges accumulated in the photodiode PD in a seventh stage (7).

Before a second data read-out for still image generation after the seventh stage, the transfer transistor TX transfers the added charges to the floating diffusion node FD similarly to the third stage described above, and upon the arrival of the timing of the second data read-out, a read-out operation is performed to generate a still image. In this manner, the first-first data is combined with the first-second data in the photodiode PD, so that only one read-out is required to obtain the combined data. In the fifth to seventh stages, times required to perform the stages may be determined according to a relative speed difference between the shutter speed and the frame rate of the live view image. Finally, only one read-out operation is performed on the first-first data and the first-second data to coincide with the shutter speed for still image generation.

When the still image is generated according to the above-described method, since it is not necessary to read out the first data for live view image generation plural times when the shutter speed is slow, noise is reduced.

Even in the above-described case, the first data for live view image generation has to be read out plural times. For example, when shutter speed is 1/30 second, and a frame rate of a live view image is 1/60 second, the first-first data for live view image generation is read out in the fourth stage, and the first-second data for live view image generation is read out again after the seventh stage. The first-second data becomes next frame data of the live view image. However, since the first-second data is data to which first data of an image frame of a previous stage is added, the subject is blurred, and thus the live view image is blurred when it is displayed.

To solve the problem, the image sensor circuit102may further include a subtractor15(illustrated inFIG. 9). As described above, the first-first data of the live view image is added to the first-second data of the live view image. The subtractor15may subtract the first-first data of the live view image from the first-second data of the live view image. The first-second data, from which the first-first data is subtracted, is then read to generate a live view image with reduced blurring.

FIGS. 8 and 9are conceptual diagrams illustrating an operation of an image generating apparatus according to an exemplary embodiment of the present general inventive concept.

As described above, it is assumed that shutter speed is 1/30 second, and a frame rate of a live view image is 1/60 seconds.

An exemplary embodiment of the present general inventive concept illustrated inFIG. 8conceptually illustrates the exemplary embodiment of the present general inventive concept illustrated inFIGS. 4 to 5B. A process of the first to fourth stages illustrated inFIGS. 5A to 5Bis performed twice to generate a first frame13and a second frame14of the live view image. Photo charge data is read out from a first pixel group310of total image pixels10to generate each frame of the live view image. When the photo charge data is read out from the first pixel group310of total image pixels10, a load for the live view image processing is reduced, and thus it is easy to process a still image independently. In the still image, photo charge data is read out from a second pixel group320corresponding to the remaining pixels of the total image pixels10, and combined with the photo charge data for the live view image generation to generate the whole image. As described above, since the frame rate of the live view image is twice the shutter speed, the data for the first pixel group310, which is read out to generate each frame of the live view image, is output twice and added together in memory223.

An exemplary embodiment of the present general inventive concept illustrated inFIG. 9conceptually illustrates the exemplary embodiment of the present general inventive concept illustrated inFIGS. 6 to 7B. In the exemplary embodiment of the present general inventive concept, a process of the first to fourth stages illustrated inFIGS. 7A to 7Bis performed to generate a first frame13of the live view image, and a process of the fifth to seventh stages illustrated inFIGS. 7A and 7Bis performed to generate a second frame14of the live view image. Similarly, photo charge data is read out from a first pixel group310of total image pixels10to generate each frame of the live view image. In the still image, photo charge data is read out from a second pixel group320corresponding to the remaining pixels of the total image pixels10, and combined with the photo charge data from the first pixel group310for the live view image generation to generate the whole image. In this exemplary embodiment of the present general inventive concept, the first-first data and the first-second data are combined in the photodiode PD, and so the data from the first pixel group310does not need to be separately combined in a memory223before being combined with the photo charge data from the second pixel group320. Unlike the exemplary embodiment of the present general inventive concept described above with reference toFIG. 8, even after the first to fourth stages are performed, the photo charge data of the floating diffusion node FD is not reset to collapse a potential barrier, and the stored photo charges are added to the photo charges of the photodiode PD. The photo charge data of the live view image for still image generation is read out once after the seventh stage is performed. With respect to the live view image, photo charge data in which the photo charge data stored to generate the first frame13from the photo charge data stored after the seventh stage is completed is used. Specifically, subtractor15subtracts the first-first data, corresponding to first frame13, from the first-second data, corresponding to second frame14, to generate the live view output with reduced blurring.

Although not illustrated in the drawings, the image generating apparatus100includes an essential configuration provided in the general electronic computing apparatus. That is, the image generating apparatus includes a hardware configuration, such as a central processing unit (CPU) having a sufficient control and logic function, a cache memory, a random access memory (RAM), a high-capacity auxiliary storage device such as a hard disc or a Blu-Ray (BD) disc, a near field communication (NFC) module, various wired and wireless communication modules including a high-definition multimedia interface (HDMI), and a data bus, and the image generating apparatus100includes an application, a framework, and an operating system which are configured to perform the function of the controller130.

Specifically, a storage unit (not illustrated) is configured to store a captured image. That is, the storage unit stores an image frame constituting the live view image or stores a still image. The storage unit may convert the captured image into an efficient form and store the converted result. The storage unit may be implemented with various techniques, and for example, the storage unit may include a memory, a hard disc drive (HDD), a Blu-Ray disc (BD), and the like. In particular, a nonvolatile memory such as an electrically erasable and programmable read only memory (EEPROM) may be used to store a captured image for processing of the captured image.

Hereinafter, an image generating method according to various exemplary embodiments of the present general inventive concept will be described.

FIGS. 10 to 13are flowcharts illustrating image generating method according to various exemplary embodiments of the present general inventive concept.

Referring toFIG. 10, an image generating method according to an exemplary embodiment of the present general inventive concept includes displaying a live view image on a screen of an image generating apparatus (operation S1010), determining if there is a shutter operation to image a still image (operation S1020), and comparing shutter speed (the frame rate of the received still image) with a frame rate of the live view image (operation S1030) when there is a shutter operation to image a still image during the display of the live view image (operation S1020-Y). When there is not a shutter operation to image a still image (operation S1020-N), the method ends.

Further, the method includes comparing the shutter speed with the frame rate of the live view image (operation S1040) and adding current frame data of the live view image to next frame data of the live view image (operation S1050) when the shutter speed is smaller than the frame rate of the live view image (operation S1040-Y). When the shutter speed is not less than the frame rate of the live view image (operation S1040-N), the method ends.

Referring toFIG. 11, an image generating method according to an exemplary embodiment of the present general inventive concept includes displaying a live view image on a screen of an image generating apparatus (operation S1110), determining if there is a shutter operation to image a still image (operation S1120), and comparing shutter speed with a frame rate of the live view image (operation S1130) when there is a shutter operation to image a still image during the display of the live view image (operation S1120-Y). When there is not a shutter operation to image a still image (operation S1120-N), the method ends.

Further, the method includes comparing the shutter speed with the frame rate of the live view image (operation S1140) and forming a potential of a direction of a photodiode by applying a bias voltage to current frame data of the live view image (operation S1150) when the shutter speed is smaller than the frame rate of the live view image as a comparison result (operation S1140-Y), and generating next frame data to which the current frame data of the live view image is added through the photodiode (operation S1160). When the shutter speed is not less than the frame rate of the live view image (operation S1140-N), the method ends.

Referring toFIG. 12, an image generating method according to an exemplary embodiment of the present general inventive concept includes displaying a live view image on a screen of an image generating apparatus (operation S1210), determining if there is a shutter operation to image a still image (operation S1220), and outputting first data from a first pixel group of an image sensor and storing the first data (operation S1230) when there is a shutter operation to image a still image during the display of the live view image (operation S1220-Y). When there is not a shutter operation to image a still image (operation S1220-N), the method ends.

Further, the method includes comparing shutter speed with a frame rate of the live view image (operation S1240) and adding current frame data of the live view image to next frame data of the live view image (operation S1250) when the shutter speed is smaller than the frame rate of the live view image as a comparison result (operation S1240-Y). Further, the method includes reading out next frame data of the live view image to which the current frame data of the live view image is added (operation S1260). When the shutter speed is not less than the frame rate of the live view image (operation S1240-N), the method ends.

Referring toFIG. 13, an image generating method according to an exemplary embodiment of the present general inventive concept includes displaying a live view image on a screen of an image generating apparatus (operation S1310), determining if there is a shutter operation to image a still image (operation S1320), and comparing shutter speed with a frame rate of the live view image (operation S1330) when there is a shutter operation to image a still image during the display of the live view image (operation S1320-Y).

Further, the method includes comparing shutter speed with a frame rate of the live view image (operation S1330) and adding current frame data of the live view image to next frame data of the live view image (operation S1340) when the shutter speed is smaller than the frame rate of the live view image as a comparison result (operation S1330-Y). Further, the method includes generating a next frame image of the live view image by subtracting the current frame data of the live view image from the next frame data of the live view image to which the current frame data of the live view image is added (operation S1350). When the shutter speed is not less than the frame rate of the live view image (operation S1330-N), the method ends.

According to the above-described various exemplary embodiments, an image generating apparatuses and method, capable of minimizing noise generated when a read-out process for exposure data of an image sensor is performed plural times to generate a still image in a state in which shutter speed is different from a frame rate of a live view image, are provided.

The image generating method may also be embedded in a hardware integrated circuit (IC) chip in an embedded software form or provided in firmware.