KR20220151324A - Electronic device to improve the visibility of video using local contrast enhancement and the method thereof - Google Patents

Abstract

An electronic device according to various embodiments includes a display including at least one pixel, a memory, and a processor operatively connected to the display and the memory. The processor may generate a second image by performing local contrast enhancement on a first image, obtain RGB values of one or more pixels in at least one frame of the first image, calculate a difference between an RGB value of a center pixel and an RGB value of at least one neighboring pixel located within a predetermined distance from the center pixel in at least one block including the center pixel and the at least one neighboring pixel, determine whether the center pixel belongs to a flat region based on the differences of the RGB values, determine a first weight for the first image and a second weight for the second image based on a ratio of pixels belonging to the flat region to all pixels, and generate a third image formed by reflecting the first image by the first weight and reflecting the second image by the second weight. The present invention aims to provide a method for alleviating a halo occurring in an area with flat gradations when using a local contrast enhancement algorithm to improve visibility in an electronic device.

Description

Method for improving image visibility using electronic device and regional contrast enhancement

This document relates to an electronic device, and relates to a method of improving visibility of an image using, for example, area contrast enhancement.

With the development of mobile communication technology and processor technology, a portable electronic device (hereinafter referred to as an electronic device) can implement various functions beyond a conventional call function. The electronic device can store and reproduce video and image files, and can receive video and image files by establishing a communication connection with an external device.

For example, the electronic device may allocate different RGB values having a predetermined grayscale range (eg, 0 to 255) to each pixel of the display. The electronic device may acquire RGB values to be assigned to each pixel from data of the image file and assign different RGB values to each frame.

Conventional electronic devices have used a local contrast enhancement algorithm that increases contrast in each area after dividing the image into regions in order to increase the visibility of the image, but this causes the image to be distorted in areas where the gradation is flat. problems may arise.

Various embodiments of this document provide a method for mitigating the image distortion phenomenon (Halo) in a flat portion of the grayscale when the area contrast enhancement algorithm is used to improve visibility in an electronic device as described above. There is a purpose.

An electronic device according to various embodiments includes a display including at least one pixel, a memory, and a processor operatively connected to the display and the memory, wherein the processor displays a first image as a regional contrast. A second image with local contrast enhancement is generated, an RGB value of at least one pixel is obtained in at least one frame of the first image, and a center pixel and at least one pixel located within a predetermined distance from the center pixel are obtained. In at least one block including peripheral pixels of, calculating the difference between the RGB value of the central pixel and the RGB value of at least one neighboring pixel, and determining whether the central pixel belongs to a flat area based on the RGB value difference. determine whether or not the first weight of the first image and the second weight of the second image are determined based on the ratio of pixels belonging to the flat region to all pixels, and determine the first weight of the first image and a third image reflecting the second weight by the second weight may be generated.

An image correction method using regional contrast enhancement according to various embodiments includes an operation of generating a second image obtained by enhancing a first image by regional contrast enhancement, and acquiring an RGB value of at least one pixel in at least one frame of the first image. In at least one block including a central pixel and at least one neighboring pixel located within a predetermined distance from the central pixel, calculating the difference between the RGB value of the central pixel and the RGB value of at least one neighboring pixel An operation of determining whether the center pixel belongs to the flat area based on the RGB value difference, a first weight value for the first image and the first weight value of the first image based on a ratio of pixels belonging to the flat area to all pixels. An operation of determining a second weight for the two images, and an operation of generating a third image by reflecting the first image by the first weight and reflecting the second image by the second weight.

According to various embodiments, the electronic device may mitigate image distortion occurring when a region contrast enhancement algorithm is used in an image. For example, the electronic device may minimize image distortion by discriminating between areas with flat gradations and areas with uneven gradations, and adjusting a reflection ratio of the enhanced image compared to the area in the areas with flat gradations. Through this, the electronic device may provide a clear image without noise while enhancing contrast.

In addition, effects that can be obtained or predicted due to various embodiments of the electronic device will be directly or implicitly disclosed in the detailed description of the embodiment of the electronic device. For example, various effects predicted according to various embodiments of an electronic device will be disclosed within the detailed description to be described later.

1 is a block diagram of an electronic device in a network environment, according to various embodiments.
2A and 2B illustrate a first image and a second image using a regional contrast enhancement algorithm according to various embodiments.
3 is a block diagram of an electronic device according to various embodiments.
4A and 4B illustrate blocks centered on one pixel in an image according to various embodiments.
5 is a flowchart of a method for improving image visibility according to various embodiments.

1 is a block diagram of an electronic device 101 within a network environment 100, according to various embodiments.

Referring to FIG. 1 , in a network environment 100, an electronic device 101 communicates with an electronic device 102 through a first network 198 (eg, a short-range wireless communication network) or through a second network 199. It may communicate with at least one of the electronic device 104 or the server 108 through (eg, a long-distance wireless communication network). According to one embodiment, the electronic device 101 may communicate with the electronic device 104 through the server 108 . According to an embodiment, the electronic device 101 includes a processor 120, a memory 130, an input module 150, an audio output module 155, a display module 160, an audio module 170, a sensor module ( 176), interface 177, connection terminal 178, haptic module 179, camera module 180, power management module 188, battery 189, communication module 190, subscriber identification module 196 , or the antenna module 197 may be included. In some embodiments, in the electronic device 101, at least one of these components (eg, the connection terminal 178) may be omitted or one or more other components may be added. In some embodiments, some of these components (eg, sensor module 176, camera module 180, or antenna module 197) are integrated into a single component (eg, display module 160). It can be.

The processor 120, for example, executes software (eg, the program 140) to cause at least one other component (eg, hardware or software component) of the electronic device 101 connected to the processor 120. It can control and perform various data processing or calculations. According to one embodiment, as at least part of data processing or operation, the processor 120 transfers instructions or data received from other components (e.g., sensor module 176 or communication module 190) to volatile memory 132. , processing commands or data stored in the volatile memory 132 , and storing resultant data in the non-volatile memory 134 . According to one embodiment, the processor 120 may include a main processor 121 (eg, a central processing unit or an application processor) or a secondary processor 123 (eg, a graphic processing unit, a neural network processing unit ( NPU: neural processing unit (NPU), image signal processor, sensor hub processor, or communication processor). For example, when the electronic device 101 includes the main processor 121 and the auxiliary processor 123, the auxiliary processor 123 may use less power than the main processor 121 or be set to be specialized for a designated function. can The secondary processor 123 may be implemented separately from or as part of the main processor 121 .

The secondary processor 123 may, for example, take the place of the main processor 121 while the main processor 121 is in an inactive (eg, sleep) state, or the main processor 121 is active (eg, running an application). ) state, together with the main processor 121, at least one of the components of the electronic device 101 (eg, the display module 160, the sensor module 176, or the communication module 190) It is possible to control at least some of the related functions or states. According to one embodiment, the auxiliary processor 123 (eg, image signal processor or communication processor) may be implemented as part of other functionally related components (eg, camera module 180 or communication module 190). have. According to one embodiment, the auxiliary processor 123 (eg, a neural network processing device) may include a hardware structure specialized for processing an artificial intelligence model. AI models can be created through machine learning. Such learning may be performed, for example, in the electronic device 101 itself where the artificial intelligence model is performed, or may be performed through a separate server (eg, the server 108). The learning algorithm may include, for example, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning, but in the above example Not limited. The artificial intelligence model may include a plurality of artificial neural network layers. Artificial neural networks include deep neural networks (DNNs), convolutional neural networks (CNNs), recurrent neural networks (RNNs), restricted boltzmann machines (RBMs), deep belief networks (DBNs), bidirectional recurrent deep neural networks (BRDNNs), It may be one of deep Q-networks or a combination of two or more of the foregoing, but is not limited to the foregoing examples. The artificial intelligence model may include, in addition or alternatively, software structures in addition to hardware structures.

The memory 130 may store various data used by at least one component (eg, the processor 120 or the sensor module 176) of the electronic device 101 . The data may include, for example, input data or output data for software (eg, program 140) and commands related thereto. The memory 130 may include volatile memory 132 or non-volatile memory 134 .

The program 140 may be stored as software in the memory 130 and may include, for example, an operating system 142 , middleware 144 , or an application 146 .

The input module 150 may receive a command or data to be used by a component (eg, the processor 120) of the electronic device 101 from the outside of the electronic device 101 (eg, a user). The input module 150 may include, for example, a microphone, a mouse, a keyboard, a key (eg, a button), or a digital pen (eg, a stylus pen).

The sound output module 155 may output sound signals to the outside of the electronic device 101 . The sound output module 155 may include, for example, a speaker or a receiver. The speaker can be used for general purposes such as multimedia playback or recording playback. A receiver may be used to receive an incoming call. According to one embodiment, the receiver may be implemented separately from the speaker or as part of it.

The display module 160 may visually provide information to the outside of the electronic device 101 (eg, a user). The display module 160 may include, for example, a display, a hologram device, or a projector and a control circuit for controlling the device. According to one embodiment, the display module 160 may include a touch sensor set to detect a touch or a pressure sensor set to measure the intensity of force generated by the touch.

The audio module 170 may convert sound into an electrical signal or vice versa. According to one embodiment, the audio module 170 acquires sound through the input module 150, the sound output module 155, or an external electronic device connected directly or wirelessly to the electronic device 101 (eg: Sound may be output through the electronic device 102 (eg, a speaker or a headphone).

The sensor module 176 detects an operating state (eg, power or temperature) of the electronic device 101 or an external environmental state (eg, a user state), and generates an electrical signal or data value corresponding to the detected state. can do. According to one embodiment, the sensor module 176 may include, for example, a gesture sensor, a gyro sensor, an air pressure sensor, a magnetic sensor, an acceleration sensor, a grip sensor, a proximity sensor, a color sensor, an IR (infrared) sensor, a bio sensor, It may include a temperature sensor, humidity sensor, or light sensor.

The interface 177 may support one or more designated protocols that may be used to directly or wirelessly connect the electronic device 101 to an external electronic device (eg, the electronic device 102). According to one embodiment, the interface 177 may include, for example, a high definition multimedia interface (HDMI), a universal serial bus (USB) interface, an SD card interface, or an audio interface.

The connection terminal 178 may include a connector through which the electronic device 101 may be physically connected to an external electronic device (eg, the electronic device 102). According to one embodiment, the connection terminal 178 may include, for example, an HDMI connector, a USB connector, an SD card connector, or an audio connector (eg, a headphone connector).

The haptic module 179 may convert electrical signals into mechanical stimuli (eg, vibration or motion) or electrical stimuli that a user may perceive through tactile or kinesthetic senses. According to one embodiment, the haptic module 179 may include, for example, a motor, a piezoelectric element, or an electrical stimulation device.

The camera module 180 may capture still images and moving images. According to one embodiment, the camera module 180 may include one or more lenses, image sensors, image signal processors, or flashes.

The power management module 188 may manage power supplied to the electronic device 101 . According to one embodiment, the power management module 188 may be implemented as at least part of a power management integrated circuit (PMIC), for example.

The battery 189 may supply power to at least one component of the electronic device 101 . According to one embodiment, the battery 189 may include, for example, a non-rechargeable primary cell, a rechargeable secondary cell, or a fuel cell.

The communication module 190 is a direct (eg, wired) communication channel or a wireless communication channel between the electronic device 101 and an external electronic device (eg, the electronic device 102, the electronic device 104, or the server 108). Establishment and communication through the established communication channel may be supported. The communication module 190 may include one or more communication processors that operate independently of the processor 120 (eg, an application processor) and support direct (eg, wired) communication or wireless communication. According to one embodiment, the communication module 190 is a wireless communication module 192 (eg, a cellular communication module, a short-range wireless communication module, or a global navigation satellite system (GNSS) communication module) or a wired communication module 194 (eg, : a local area network (LAN) communication module or a power line communication module). Among these communication modules, a corresponding communication module is a first network 198 (eg, a short-range communication network such as Bluetooth, wireless fidelity (WiFi) direct, or infrared data association (IrDA)) or a second network 199 (eg, legacy It may communicate with the external electronic device 104 through a cellular network, a 5G network, a next-generation communication network, the Internet, or a telecommunications network such as a computer network (eg, a LAN or a WAN). These various types of communication modules may be integrated as one component (eg, a single chip) or implemented as a plurality of separate components (eg, multiple chips). The wireless communication module 192 uses subscriber information (eg, International Mobile Subscriber Identifier (IMSI)) stored in the subscriber identification module 196 within a communication network such as the first network 198 or the second network 199. The electronic device 101 may be identified or authenticated.

The wireless communication module 192 may support a 5G network after a 4G network and a next-generation communication technology, for example, NR access technology (new radio access technology). NR access technologies include high-speed transmission of high-capacity data (enhanced mobile broadband (eMBB)), minimization of terminal power and access of multiple terminals (massive machine type communications (mMTC)), or high reliability and low latency (ultra-reliable and low latency (URLLC)). -latency communications)) can be supported. The wireless communication module 192 may support a high frequency band (eg, mmWave band) to achieve a high data rate, for example. The wireless communication module 192 uses various technologies for securing performance in a high frequency band, such as beamforming, massive multiple-input and multiple-output (MIMO), and full-dimensional multiplexing. Technologies such as input/output (FD-MIMO: full dimensional MIMO), array antenna, analog beam-forming, or large scale antenna may be supported. The wireless communication module 192 may support various requirements defined for the electronic device 101, an external electronic device (eg, the electronic device 104), or a network system (eg, the second network 199). According to one embodiment, the wireless communication module 192 is a peak data rate for eMBB realization (eg, 20 Gbps or more), a loss coverage for mMTC realization (eg, 164 dB or less), or a U-plane latency for URLLC realization (eg, Example: downlink (DL) and uplink (UL) each of 0.5 ms or less, or round trip 1 ms or less) may be supported.

The antenna module 197 may transmit or receive signals or power to the outside (eg, an external electronic device). According to one embodiment, the antenna module 197 may include an antenna including a radiator formed of a conductor or a conductive pattern formed on a substrate (eg, PCB). According to one embodiment, the antenna module 197 may include a plurality of antennas (eg, an array antenna). In this case, at least one antenna suitable for a communication method used in a communication network such as the first network 198 or the second network 199 is selected from the plurality of antennas by the communication module 190, for example. can be chosen A signal or power may be transmitted or received between the communication module 190 and an external electronic device through the selected at least one antenna. According to some embodiments, other components (eg, a radio frequency integrated circuit (RFIC)) may be additionally formed as a part of the antenna module 197 in addition to the radiator.

According to various embodiments, the antenna module 197 may form a mmWave antenna module. According to one embodiment, the mmWave antenna module includes a printed circuit board, an RFIC disposed on or adjacent to a first surface (eg, a lower surface) of the printed circuit board and capable of supporting a designated high frequency band (eg, mmWave band); and a plurality of antennas (eg, array antennas) disposed on or adjacent to a second surface (eg, a top surface or a side surface) of the printed circuit board and capable of transmitting or receiving signals of the designated high frequency band. can do.

At least some of the components are connected to each other through a communication method between peripheral devices (eg, a bus, general purpose input and output (GPIO), serial peripheral interface (SPI), or mobile industry processor interface (MIPI)) and signal ( e.g. commands or data) can be exchanged with each other.

According to an embodiment, commands or data may be transmitted or received between the electronic device 101 and the external electronic device 104 through the server 108 connected to the second network 199 . Each of the external electronic devices 102 or 104 may be the same as or different from the electronic device 101 . According to an embodiment, all or part of operations executed in the electronic device 101 may be executed in one or more external electronic devices among the external electronic devices 102 , 104 , or 108 . For example, when the electronic device 101 needs to perform a certain function or service automatically or in response to a request from a user or another device, the electronic device 101 instead of executing the function or service by itself. Alternatively or additionally, one or more external electronic devices may be requested to perform the function or at least part of the service. One or more external electronic devices receiving the request may execute at least a part of the requested function or service or an additional function or service related to the request, and deliver the execution result to the electronic device 101 . The electronic device 101 may provide the result as at least part of a response to the request as it is or additionally processed. To this end, for example, cloud computing, distributed computing, mobile edge computing (MEC), or client-server computing technology may be used. The electronic device 101 may provide an ultra-low latency service using, for example, distributed computing or mobile edge computing. In another embodiment, the external electronic device 104 may include an internet of things (IoT) device. Server 108 may be an intelligent server using machine learning and/or neural networks. According to one embodiment, the external electronic device 104 or server 108 may be included in the second network 199 . The electronic device 101 may be applied to intelligent services (eg, smart home, smart city, smart car, or health care) based on 5G communication technology and IoT-related technology.

Electronic devices according to various embodiments disclosed in this document may be devices of various types. The electronic device may include, for example, a portable communication device (eg, a smart phone), a computer device, a portable multimedia device, a portable medical device, a camera, a wearable device, or a home appliance. An electronic device according to an embodiment of the present document is not limited to the aforementioned devices.

Various embodiments of this document and terms used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, like reference numbers may be used for like or related elements. The singular form of a noun corresponding to an item may include one item or a plurality of items, unless the relevant context clearly dictates otherwise. In this document, "A or B", "at least one of A and B", "at least one of A or B", "A, B or C", "at least one of A, B and C", and "A Each of the phrases such as "at least one of , B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first", "second", or "first" or "secondary" may simply be used to distinguish a given component from other corresponding components, and may be used to refer to a given component in another aspect (eg, importance or order) is not limited. A (e.g., first) component is said to be "coupled" or "connected" to another (e.g., second) component, with or without the terms "functionally" or "communicatively." When mentioned, it means that the certain component may be connected to the other component directly (eg by wire), wirelessly, or through a third component.

The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and is interchangeable with terms such as, for example, logic, logical blocks, parts, or circuits. can be used as A module may be an integrally constructed component or a minimal unit of components or a portion thereof that performs one or more functions. For example, according to one embodiment, the module may be implemented in the form of an application-specific integrated circuit (ASIC).

Various embodiments of this document provide one or more instructions stored in a storage medium (eg, internal memory 136 or external memory 138) readable by a machine (eg, electronic device 101). It may be implemented as software (eg, the program 140) including them. For example, a processor (eg, the processor 120 ) of a device (eg, the electronic device 101 ) may call at least one command among one or more instructions stored from a storage medium and execute it. This enables the device to be operated to perform at least one function according to the at least one command invoked. The one or more instructions may include code generated by a compiler or code executable by an interpreter. The device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-temporary' only means that the storage medium is a tangible device and does not contain a signal (e.g. electromagnetic wave), and this term refers to the case where data is stored semi-permanently in the storage medium. It does not discriminate when it is temporarily stored.

According to one embodiment, the method according to various embodiments disclosed in this document may be included and provided in a computer program product. Computer program products may be traded between sellers and buyers as commodities. A computer program product is distributed in the form of a device-readable storage medium (eg compact disc read only memory (CD-ROM)), or through an application store (eg Play Store ^TM ) or on two user devices ( It can be distributed (eg downloaded or uploaded) online, directly between smart phones. In the case of online distribution, at least part of the computer program product may be temporarily stored or temporarily created in a device-readable storage medium such as a manufacturer's server, an application store server, or a relay server's memory.

According to various embodiments, each component (eg, module or program) of the above-described components may include a single object or a plurality of entities, and some of the plurality of entities may be separately disposed in other components. have. According to various embodiments, one or more components or operations among the aforementioned corresponding components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (eg modules or programs) may be integrated into a single component. In this case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by a corresponding component of the plurality of components prior to the integration. . According to various embodiments, the actions performed by a module, program, or other component are executed sequentially, in parallel, iteratively, or heuristically, or one or more of the actions are executed in a different order, or omitted. or one or more other actions may be added.

2A and 2B illustrate a first image and a second image using a regional contrast enhancement algorithm according to various embodiments.

According to various embodiments, the electronic device may improve visibility of an image using a local contrast enhancement algorithm. Using the local contrast enhancement algorithm, the electronic device may increase the sharpness of a part of the image where contrast is insufficient. Image contrast refers to the difference between a dark part and a bright part in an image. If the image contrast is strong, the difference between the bright part and the dark part is large, and if the image contrast is weak, the difference between the bright part and the dark part may be small. When a viewer views an image, if the contrast is weak, the sharpness and visibility of the image may deteriorate. An electronic device may use various methods (contrast enhancement, CE) to increase the contrast of an image.

For example, the electronic device may use a direct enhancement method (eg, power series transformation, log function transformation, gray level division method) for enhancing the contrast of an image and/or video expressed by a predetermined contrast value. Alternatively, the electronic device may use an indirect enhancement method (eg, histogram specification, histogram equalization, histogram modification) for improving contrast by redistributing probability densities of images and/or videos.

According to various embodiments, the electronic device may use a regional contrast enhancement algorithm to enhance image contrast. 2A shows the screen 200 before performing regional contrast enhancement, and FIG. 2B shows the screen 210 after performing regional contrast enhancement. Referring to FIG. 2A , an image reproduced by an electronic device may include a flat area or an uneven area. The electronic device may perform area contrast enhancement in both a flat area and a non-flat area. When performing regional contrast enhancement, image distortion (eg, halo phenomenon) may occur because RGB values of pixels on which regional contrast enhancement is performed are not sufficiently increased in a flat area due to an area having a high RGB value nearby. On the other hand, relatively little image distortion may occur even when regional contrast enhancement is performed in an uneven area.

According to various embodiments, the electronic device may maintain the current pixel RGB value when the RGB value of the surrounding pixel is high based on the RGB value of the current pixel, and increase the RGB value of the current pixel when the RGB value of the surrounding pixel is low. Through the regional contrast enhancement algorithm, the electronic device can locally increase the contrast of the image. A sharp image can be obtained in an image with few flat areas by using the local contrast enhancement algorithm, but image distortion may occur around pixels with high RGB values in images with many flat areas. For example, when an electronic device performs an area contrast enhancement algorithm, if the RGB values of neighboring pixels are high, the RGB values of the central pixel may not be sufficiently increased. Therefore, image distortion may occur between the central pixel having a high RGB value of the surrounding pixels and the central pixel having a low RGB value of the surrounding pixels due to the difference in the performance of the regional contrast enhancement algorithm.

For example, referring to FIGS. 2A and 2B , the background color of the first area 212 and the second area 214 are the same, but a difference occurs in the image 210 of FIG. 2B after performing the regional contrast enhancement algorithm. . Since the RGB values of the pixels displaying the graphic object in the first area 212 are higher than the RGB values of the background color, the processor may increase the RGB values of the central pixels less when performing the regional contrast enhancement algorithm. As a result, image distortion may occur due to the regional contrast enhancement algorithm performed by the processor in the first region 212 . On the other hand, since the RGB values of the pixels located in the second region 214 are similar, image distortion may not occur.

According to various embodiments, the electronic device may adjust a reflection ratio of an image on which a regional contrast enhancement algorithm is performed in order to prevent image distortion. For example, the electronic device may generate a third image by reflecting the first image by a first weight and reflecting the second image by a second weight. A method of mitigating image distortion and improving visibility of an image by adjusting a reflection ratio of an image subjected to regional contrast enhancement by an electronic device will be described later with reference to FIGS. 3 to 5 .

3 is a block diagram of an electronic device according to various embodiments.

Referring to FIG. 3 , an electronic device 300 may include a display 320, a processor 310, and a memory 330, and in various embodiments, some of the illustrated components may be omitted or replaced. The electronic device 300 may further include at least some of the configurations and/or functions of the electronic device 101 of FIG. 1 . At least some of the components of the illustrated (or not illustrated) electronic device 300 may be operatively, functionally, and/or electrically connected to each other.

According to various embodiments, the display 320 may display various images under the control of the processor 310 (eg, AP or DDI). The display 320 may be a liquid crystal display (LCD), a light-emitting diode (LED) display, a micro LED display, a quantum dot (QD) display, or an organic light emitting diode (QD) display. -Emitting diode (OLED)) may be implemented as any one of displays, but is not limited thereto. The display 320 may be formed as a touch screen that senses a touch and/or proximity touch (or hovering) input using a user's body part (eg, a finger) or an input device (eg, a stylus pen). The display 320 may include at least some of the components and/or functions of the display module 160 of FIG. 1 .

According to various embodiments, at least a portion of the display 320 may be flexible, and may be implemented as a foldable display or a rollable display.

According to various embodiments, the memory 330 includes a volatile memory (eg, the volatile memory 132 of FIG. 1 ) and a non-volatile memory (eg, the non-volatile memory 134 of FIG. 1 ), and temporarily stores various data. or stored permanently. The memory 330 includes at least some of the configuration and/or functions of the memory 130 of FIG. 1 and may store the program 140 of FIG. 1 .

According to various embodiments, the memory 330 may store various instructions that may be executed by the processor 310 . These instructions may include control commands such as arithmetic and logical operations, data movement, input/output, and the like that may be recognized by the processor 310 .

According to various embodiments, the processor 310 operatively, functionally, and/or with each component of the electronic device 300 (eg, the display 320 and the memory 330). It may be electrically connected and may be configured to perform calculations or data processing related to control and/or communication of each component. The processor 310 may include at least some of the components and/or functions of the processor 120 of FIG. 1 .

According to various embodiments, calculation and data processing functions that the processor 310 can implement on the electronic device 300 will not be limited, but various embodiments for improving the visibility of an image will be described below. Operations of the processor 310 to be described later may be performed by loading instructions stored in the memory 330.

According to various embodiments, the processor 310 may control the DDI to display the first image on the display 320 . The processor 310 may reproduce a first image stored in the memory 330 or a first image received from an external device. The processor 310 may allocate an RGB value to each pixel of the display 320 based on data of the first image. The RGB values may include R (red) data, G (green) data, and B (blue) data. The R data, G data, and B data may include information about gradation of each color having a predetermined range (eg, 0 to 255).

According to various embodiments, the processor 310 may generate a second image whose contrast is enhanced compared to the first image by performing a regional contrast enhancement algorithm on the first image. The processor 310 may perform regional contrast enhancement using the following algorithm. First, the processor 310 may check the RGB values of the first pixel and surrounding pixels. The surrounding pixels may include at least one pixel located within a predetermined distance from the first pixel. The processor 310 maintains the RGB values of the first pixel when the RGB values of the surrounding pixels are higher than the RGB values of the first pixel, and maintains the RGB values of the first pixel when the RGB values of the surrounding pixels are lower than the RGB values of the first pixel. The contrast can be locally increased by increasing the RGB values of . For example, if the RGB value of the first pixel is 100 and the RGB values of neighboring pixels are 150, the processor 310 may maintain the RGB value of the first pixel without changing it. On the other hand, when the RGB value of the first pixel is 100 and the RGB value of the surrounding pixels is 50, the processor 310 can increase the RGB value of the first pixel to increase the RGB value difference with the surrounding pixels. According to an embodiment, the processor 310 may increase the overall contrast of an image by performing a local contrast enhancement algorithm on all pixels. According to an embodiment, the processor 310 may perform regional contrast enhancement on a portion having a relatively low RGB value in the entire area.

According to various embodiments, the processor 310 may create a block centered on one pixel. According to one embodiment, the processor 310 may determine the shape of the block in various ways. For example, the block generated by the processor 310 may include only pixels positioned in the same row as the center pixel or may include only pixels positioned in the same column as the center pixel. According to another embodiment, the processor 310 may generate a block including a region including at least one pixel located within a predetermined distance from the center pixel. That is, the processor 310 may create a block having a shape such as a circle, a rectangle, or a triangle around one pixel.

According to various embodiments, the processor 310 may determine a threshold to determine whether a pixel belongs to a flat region. The processor 310 may determine a threshold value capable of improving image distortion while improving image contrast. That is, if the threshold is too high, the number of pixels belonging to the flat region increases, and the area contrast enhancement effect may deteriorate. If the threshold is too low, the number of pixels belonging to the flat region decreases, and image distortion cannot be improved. Accordingly, the processor 310 may determine the threshold by selecting an appropriate value.

According to various embodiments, the processor 310 may obtain RGB values of at least one pixel. The processor 310 may check the data of the first image and allocate a different RGB value for each frame to at least one pixel constituting the display 320 . The processor 310 may obtain RGB values of the central pixel and RGB values of neighboring pixels in order to determine whether the central pixel belongs to the flat area.

For example, the processor 310 may obtain an RGB value of at least one pixel included in the first block having the first pixel as a center pixel. The processor 310 may calculate a difference between RGB values of the first pixel and neighboring pixels included in the first block. According to an embodiment, the processor 310 may calculate an average of RGB values of neighboring pixels and calculate a difference between the average value and an RGB value of the first pixel.

According to various embodiments, the processor 310 may determine whether the first pixel is included in the flat area based on the calculated difference. The processor 310 may determine that the first pixel is included in the flat area when a difference between the RGB values of the first pixel and the RGB values of neighboring pixels is less than a threshold value. Conversely, when the difference between the RGB values of the first pixel and the RGB values of neighboring pixels is greater than or equal to the threshold value, the processor 310 may determine that the first pixel is not included in the flat area. In the same way, the processor 310 may determine whether all pixels included in the display 320 are included in the flat area. According to an exemplary embodiment, when regional contrast enhancement is performed on the first image, the more flat regions in the first image are, the more easily image distortion occurs, and the smaller the flat regions, the less likely the image distortion phenomenon will appear.

According to various embodiments, the processor 310 may determine the first weight and the second weight. The processor 310 may determine the first weight and the second weight as one of numbers between 0 and 1, respectively. According to an embodiment, the processor 310 may determine a weight based on a ratio of pixels included in the flat region to all pixels. For example, when a ratio occupied by pixels included in the flat area to all pixels is the first ratio, the processor 310 may set a second weight proportional to the first ratio. The processor 310 may calculate the first weight based on the second weight. For example, the first weight may be calculated so that the sum of the first weight and the second weight becomes 1.

According to another embodiment, the processor 310 may calculate a degree of flatness of a pixel. The processor 310 may calculate the degree of flatness based on a difference between RGB values of a central pixel and RGB values of neighboring pixels within a block. The processor 310 may indicate the degree of smoothness of each pixel with a value within a predetermined range (eg, 0 to 1) based on the difference between the RGB values of the central pixel and the RGB values of the peripheral pixels. For example, when the difference between the RGB values of the first pixel and the RGB values of pixels adjacent to the first pixel is smaller than the difference between the RGB values of the second pixel and the RGB values of pixels surrounding the second pixel, the processor 310 ) may determine that the first pixel is flatter than the second pixel, and assign a number according to the flatness of each pixel.

According to various embodiments, the processor 310 may determine the first weight and the second weight based on the calculated flatness of the pixel. The lower the flatness, the larger the difference between the RGB values of the central pixel and the RGB values of the surrounding pixels, and the higher the flatness, the smaller the difference between the RGB values of the central pixel and the surrounding pixels. The processor 310 may determine a high first weight for pixels with high flatness to reduce image distortion, and may set a high second weight for pixels with low flatness to improve visibility.

According to various embodiments, the processor 310 may generate a third image by combining the first image and the second image. According to an embodiment, the processor 310 may combine the first image and the second image based on the calculated first weight and second weight. For example, the processor 310 may combine the first image and the second image using Equation 1 below. The processor 310 checks the RGB value of the first pixel in the first image and the RGB value of the first pixel in the second image with respect to the predetermined frame, and substitutes the RGB value of the first pixel in the third image into Equation 1. value can be determined. In the same way, the processor 310 may determine RGB values for all pixels of the third image.

[Equation 1]

4A and 4B illustrate blocks centered on one pixel in an image according to various embodiments.

According to various embodiments, a processor (eg, the processor 310 of FIG. 3 ) may generate a block including at least one pixel to perform regional contrast enhancement. The processor may determine a center pixel and generate a block including at least one pixel located within a predetermined distance from the center pixel. The processor may set the shape of the block in various ways. For example, the shape of a block may vary according to factors such as image characteristics, a current state of a terminal (eg, whether or not it is in a power saving mode), and a battery level.

4A is an example of an image with few flat areas. The processor may perform regional contrast enhancement on a region having a relatively low RGB value in the image of FIG. 4A. According to an embodiment, the processor increases the center pixel RGB value when the RGB values of the surrounding pixels are lower than the RGB values of the center pixel, and maintains the RGB values of the center pixel when the RGB values of the surrounding pixels are higher than the RGB values of the center pixel. Contrast can be increased.

According to various embodiments, when the processor performs regional contrast enhancement on an image with a small number of flat regions, image distortion may occur less. In the image shown in FIG. 4A , image distortion does not occur easily even when regional contrast enhancement is performed, and thus contrast is improved and a clear image can be obtained. Therefore, the local contrast enhancement algorithm may be applied as it is to enhance contrast in the image of FIG. 4A.

For example, the processor may set the first block 410 having the first pixel 412 as a center pixel. The processor may obtain RGB values of the pixels included in the first block 410 and calculate a difference between the RGB values of the first pixel 412 and the RGB values of neighboring pixels. The image 400 of FIG. 4A is an image with a small flat area, and a difference between the RGB values of the first pixel 412 and the RGB values of neighboring pixels may be calculated to be greater than a threshold value. That is, since the ratio of the flat area is low, image distortion may occur less even when the area contrast enhancement algorithm is performed. The processor may determine the second weight to be high in order to improve the visibility of the image. When creating a third image from the image of FIG. 4A, the processor may lower the reflection ratio of the first image and increase the reflection ratio of the second image. That is, the processor may set the first weight low and set the second weight high.

FIG. 4B is an example of an image with many flat areas, and is an image in which the color difference of each pixel is not large except for a part of the message display area. The processor may perform regional contrast enhancement on an area having a relatively low RGB value in the image 420 of FIG. 4B. According to an embodiment, when a processor performs an area contrast enhancement algorithm on an image having many flat areas as shown in FIG. 4B , image distortion may occur.

For example, distortion of an image may occur near a boundary line where a color is changed. The processor may generate the second block 430 having the second pixel 432 located near the boundary as a center pixel and perform the regional contrast enhancement algorithm. When performing the regional contrast enhancement algorithm, the processor may check RGB values of pixels around the second pixel 432 . The processor may maintain the RGB values of the second pixel 432 when the RGB values of the surrounding pixels are high, and increase the RGB values of the second pixel 432 when the RGB values of the surrounding pixels are low. That is, when the RGB values of pixels around the second pixel 432 are high, the RGB values are not increased. However, when a pixel having a low RGB value exists around the third pixel having the same RGB value as the second pixel 432, the processor may increase the RGB value of the third pixel. Therefore, although the RGB values of the second pixel 432 and the third pixel are the same in the first image, image distortion may occur in which the RGB values are different in the second image.

According to various embodiments, the processor may determine the first weight and the second weight based on a ratio of pixels belonging to the flat region to all pixels. For example, if the ratio of pixels belonging to the flat region to all pixels is 10%, the processor may set the second weight to 0.1, and if the ratio of pixels belonging to the flat region to all pixels is 20%, The processor may set the second weight to 0.2. According to another embodiment, the processor may determine the first weight and the second weight according to the flatness of the pixel. The processor may determine flatness of each pixel based on a difference between an RGB value of a central pixel and an RGB value of neighboring pixels in a block.

According to various embodiments, the processor may determine the first weight based on the second weight. For example, the processor may determine the first weight such that 1 is obtained by adding the first weight and the second weight. That is, the processor may determine the first weight to be 0.8 when the second weight is determined to be 0.2.

According to various embodiments, the processor may generate a third image based on the determined first weight and second weight. Specifically, the processor may generate a third image by reflecting the first image by the first weight and by reflecting the second image by the second weight. When the first image has many flat regions, the processor may increase the first weight to minimize image distortion, and increase the second weight when the first image has few flat regions to improve image visibility.

An electronic device according to various embodiments includes a display including at least one pixel, a memory, and a processor operatively connected to the display and the memory, wherein the processor displays a first image as a regional contrast. A second image with local contrast enhancement is generated, an RGB value of at least one pixel is obtained in at least one frame of the first image, and a center pixel and at least one pixel located within a predetermined distance from the center pixel are obtained. In at least one block including peripheral pixels of, calculating the difference between the RGB value of the central pixel and the RGB value of at least one neighboring pixel, and determining whether the central pixel belongs to a flat area based on the RGB value difference. determine whether or not the first weight of the first image and the second weight of the second image are determined based on the ratio of pixels belonging to the flat region to all pixels, and determine the first weight of the first image and a third image reflecting the second weight by the second weight may be generated.

According to various embodiments, the processor determines a threshold value for a difference between an RGB value of the central pixel and an RGB value of at least one neighboring pixel, and if the RGB value difference is less than or equal to the threshold value, the central pixel It is determined that the pixels belong to the flat region, and if the RGB value difference exceeds the threshold value, the center pixel may be determined not to belong to the flat region.

According to various embodiments, the processor may calculate flatness of at least one pixel based on the RGB value difference.

According to various embodiments, the display includes a row and a column of at least one pixel, and the processor includes at least one pixel positioned within the predetermined distance from the center pixel, or the same row as the center pixel. A block including only at least one pixel positioned at , or at least one pixel positioned at the same column may be created.

According to various embodiments, the processor may determine the predetermined distance for generating the block.

According to various embodiments, the processor may determine the first weight and the second weight in proportion to a ratio occupied by pixels belonging to the flat region among all pixels.

According to various embodiments, the processor may determine a first weight and a second weight based on a ratio of pixels belonging to the flat region to all pixels and image characteristics.

According to various embodiments, the processor calculates a flatness of the central pixel by calculating a difference between an RGB value of the central pixel and an RGB value of the peripheral pixels, and calculates the flatness of the central pixel, and determines the first weight value based on the flatness of the central pixel. and the second weight value may be determined.

5 is a flowchart of a method for improving image visibility according to various embodiments.

According to various embodiments, the electronic device may display and reproduce the first image on a display (eg, the display 320 of FIG. 3 ). The electronic device may reproduce a first image stored in a memory (eg, the memory 330 of FIG. 3 ) or may reproduce a first image received from an external device. The electronic device may allocate an RGB value to each pixel of the display based on the data of the first image. The RGB values may include R (red) data, G (green) data, and B (blue) data. The R data, G data, and B data may include information about gradation of each color having a predetermined range (eg, 0 to 255).

According to various embodiments, in operation 502, the electronic device may generate a second image obtained by performing local contrast enhancement on the first image. The electronic device checks the RGB values of the first pixel and the surrounding pixels, and if the RGB values of the surrounding pixels are higher than the RGB values of the first pixel, the electronic device maintains the RGB values of the first pixel and determines that the RGB values of the surrounding pixels are the first. When the RGB value of the pixel is lower than that of the pixel, contrast may be locally increased by increasing the RGB value of the first pixel. According to an embodiment, the electronic device may increase overall contrast of an image by performing a regional contrast enhancement algorithm on all pixels. According to an embodiment, the electronic device may perform regional contrast enhancement on a portion having a relatively low RGB value in the entire area.

According to various embodiments, in operation 504, the electronic device may determine at least one block including a central pixel and at least one neighboring pixel. According to an embodiment, the electronic device may variously determine the shape of a block. For example, a block generated by an electronic device may include only pixels located in the same row as the center pixel or only pixels located in the same column as the center pixel. According to another embodiment, the electronic device may create a block including a region including at least one pixel located within a predetermined distance from the center pixel. That is, the electronic device may create a block having a shape such as a circle, a rectangle, or a triangle around one pixel.

According to various embodiments, the electronic device may determine a threshold to determine whether a pixel belongs to a flat region. The electronic device may determine a threshold value capable of improving image distortion while improving image contrast. That is, if the threshold is too high, the number of pixels belonging to the flat region increases, and the area contrast enhancement effect may deteriorate. If the threshold is too low, the number of pixels belonging to the flat region decreases, and image distortion may not be improved. Therefore, the electronic device can determine the threshold by selecting an appropriate value.

According to various embodiments, an electronic device may acquire RGB values of at least one pixel. The electronic device may check the data of the first image and allocate a different RGB value for each frame to at least one pixel constituting the display. The electronic device may acquire RGB values of the central pixel and RGB values of neighboring pixels in order to determine whether the central pixel belongs to the flat area.

According to various embodiments, in operation 506, the electronic device may determine whether each pixel is included in the flat region in various ways. For example, the electronic device may determine that the center pixel is included in the flat area when the difference between the RGB values of the center pixel and the RGB values of the neighboring pixels in the first block is less than a threshold value. Conversely, when the difference between the RGB values of the center pixel and the RGB values of the neighboring pixels is greater than or equal to the threshold value, the electronic device may determine that the center pixel is not included in the flat area. In the same way, the electronic device can determine whether all pixels included in the display are included in the flat area.

According to another embodiment, the electronic device may determine that the center pixel does not belong to the flat region when there is at least one pixel exceeding a threshold among neighboring pixels in one block.

According to another embodiment, the electronic device may determine whether the center pixel is a flat region based on a ratio of pixels exceeding a threshold value among neighboring pixels in all pixels of a block. For example, the electronic device may determine that the center pixel is not a flat area only when the ratio of all pixels in the block to the neighboring pixels exceeding the threshold does not exceed the first ratio. According to another embodiment, the electronic device may The average value of the RGB values of pixels around the block is calculated, and whether or not the block is a flat area can be determined based on the difference between the average value and the RGB value of the central pixel. For example, when the difference between the average RGB value of the peripheral pixels and the RGB value of the center pixel is less than the reference value, the electronic device may determine that the center pixel belongs to the flat area.

According to another embodiment, in operation 506, the electronic device may calculate a flatness of a pixel. The electronic device may calculate the degree of flatness based on a difference between RGB values of a central pixel and RGB values of neighboring pixels within a block. The electronic device may indicate the degree of flatness with a value within a predetermined range (eg, 0 to 1) based on the difference between the center pixel RGB value and the peripheral pixel RGB value of each pixel.

According to an embodiment, the electronic device may calculate the flatness of the central pixel based on a ratio of peripheral pixels exceeding a threshold among all pixels belonging to the first block. For example, when the ratio of all pixels of the first block to the neighboring pixels exceeding the threshold is 50%, the electronic device may determine the flatness of the center pixel of the first block as 0.5.

According to various embodiments, in operation 508, the electronic device may determine a first weight and a second weight. According to an embodiment, the electronic device may determine a weight based on a ratio of pixels included in the flat region to all pixels. The electronic device may determine the first weight and the second weight as one of numbers between 0 and 1, respectively. For example, the electronic device may calculate the first weight so that the sum of the first weight and the second weight becomes 1.

According to various embodiments, the electronic device may determine the first weight and the second weight based on the calculated flatness of the pixel. The lower the flatness, the larger the difference between the RGB values of the central pixel and the RGB values of the surrounding pixels, and the higher the flatness, the smaller the difference between the RGB values of the central pixel and the surrounding pixels. The electronic device may determine a high first weight for pixels with high flatness to reduce image distortion, and may set a high second weight for pixels with low flatness to improve visibility.

According to various embodiments, in operation 510, the electronic device may generate a third image by combining the first image and the second image. According to an embodiment, the electronic device may combine the first image and the second image based on the calculated first weight and second weight. The electronic device may determine the RGB value of the first pixel in the third image by checking the RGB value of the first pixel in the first image and the RGB value of the first pixel in the second image with respect to the predetermined frame. In the same way, the electronic device can determine RGB values for all pixels of the third image.

An image correction method using regional contrast enhancement according to various embodiments includes an operation of generating a second image obtained by enhancing a first image by regional contrast enhancement, and acquiring an RGB value of at least one pixel in at least one frame of the first image. In at least one block including a central pixel and at least one neighboring pixel located within a predetermined distance from the central pixel, calculating the difference between the RGB value of the central pixel and the RGB value of at least one neighboring pixel An operation of determining whether the center pixel belongs to the flat area based on the RGB value difference, a first weight value for the first image and the first weight value of the first image based on a ratio of pixels belonging to the flat area to all pixels. An operation of determining a second weight for the two images, and an operation of generating a third image by reflecting the first image by the first weight and reflecting the second image by the second weight.

According to various embodiments, the determining whether the central pixel belongs to the flat region may include determining a threshold value for a difference between an RGB value of the central pixel and an RGB value of at least one neighboring pixel; and determining that the central pixel belongs to the flat region when the RGB value difference is less than or equal to the threshold value, and determining that the central pixel does not belong to the flat region when the RGB value difference exceeds the threshold value. can

According to various embodiments, an operation of calculating a flatness of at least one pixel based on the RGB value difference may be further included.

According to various embodiments, at least one pixel positioned within the predetermined distance from the center pixel is included, at least one pixel positioned in the same row as the center pixel, or at least one pixel positioned in the same column as the center pixel is included. An operation of generating a block including the block may be further included.

According to various embodiments, an operation of determining the predetermined distance for generating the block may be further included.

According to various embodiments, the determining of the first weight and the second weight may include determining the first weight and the second weight in proportion to a ratio occupied by pixels belonging to the flat region among all pixels. can include

According to various embodiments, the determining of the first weight and the second weight may include determining the first weight and the second weight based on a ratio of pixels belonging to the flat region to all pixels and image characteristics. can include

According to various embodiments, the determining of the first weight and the second weight may include calculating a flatness of the center pixel by calculating a difference between RGB values of the central pixel and RGB values of the peripheral pixels; and and determining the first weight and the second weight based on the flatness of the central pixel.

Claims (16)

In electronic devices,
a display comprising at least one pixel;
Memory; and
a processor operatively connected with the display and the memory;
the processor,
generating a second image obtained by performing local contrast enhancement on the first image;
obtaining RGB values of at least one pixel in at least one frame of the first image;
In at least one block including a central pixel and at least one neighboring pixel located within a predetermined distance from the central pixel, calculating a difference between an RGB value of the central pixel and an RGB value of at least one neighboring pixel;
determining whether the center pixel belongs to a flat area based on the RGB value difference;
determining a first weight for the first image and a second weight for the second image based on a ratio of pixels belonging to the flat region to all pixels;
The electronic device configured to generate a third image by reflecting the first image by a first weight and by reflecting the second image by a second weight.
According to claim 1,
the processor,
determining a threshold value for a difference between an RGB value of the central pixel and an RGB value of at least one peripheral pixel;
If the RGB value difference is less than or equal to the threshold value, it is determined that the center pixel belongs to a flat area;
The electronic device configured to determine that the central pixel does not belong to a flat region when the RGB value difference exceeds the threshold value.
According to claim 1,
the processor,
An electronic device configured to calculate flatness of at least one pixel based on the RGB value difference.
According to claim 1,
The display includes rows and columns of at least one pixel;
the processor,
To generate a block including at least one pixel located within the predetermined distance from the center pixel, including only at least one pixel located in the same row as the center pixel, or including only at least one pixel located in the same column as the center pixel set electronics.
According to claim 1,
the processor,
An electronic device configured to determine the predetermined distance for generating the block.
According to claim 1,
the processor,
The electronic device configured to determine the first weight and the second weight in proportion to a ratio occupied by pixels belonging to the flat region among all pixels.
According to claim 1,
the processor,
An electronic device configured to determine a first weight and a second weight based on a ratio of pixels belonging to the flat region to all pixels and image characteristics.
According to claim 1,
the processor,
Calculate a degree of flatness of the center pixel by calculating a difference between the RGB values of the center pixel and the RGB values of the surrounding pixels;
The electronic device configured to determine the first weight and the second weight based on the degree of flatness of the central pixel.
In the image correction method using regional contrast enhancement,
An operation of generating a second image by enhancing the first image compared to the region;
obtaining an RGB value of at least one pixel in at least one frame of the first image;
Calculating a difference between an RGB value of the central pixel and an RGB value of at least one neighboring pixel in at least one block including a central pixel and at least one neighboring pixel located within a predetermined distance from the central pixel;
determining whether the center pixel belongs to a flat area based on the RGB value difference;
determining a first weight for the first image and a second weight for the second image based on a ratio of pixels belonging to the flat region to all pixels; and
and generating a third image by reflecting the first image by a first weight and by reflecting the second image by a second weight.
According to claim 9,
The operation of determining whether the center pixel belongs to the flat region,
determining a threshold for a difference between an RGB value of the central pixel and an RGB value of at least one neighboring pixel;
determining that the center pixel belongs to a flat region when the RGB value difference is less than or equal to the threshold value; and
and determining that the center pixel does not belong to a flat region when the RGB value difference exceeds the threshold value.
According to claim 9,
The method further comprising calculating a flatness of at least one pixel based on the RGB value difference.
According to claim 9,
Generating a block including at least one pixel located within the predetermined distance from the center pixel, including only at least one pixel located in the same row as the center pixel, or including only at least one pixel located in the same column How to include more action.
According to claim 9,
The method further comprising determining the predetermined distance for generating the block.
According to claim 9,
The operation of determining the first weight and the second weight,
and determining the first weight and the second weight in proportion to a ratio occupied by pixels belonging to the flat region among all pixels.
According to claim 9,
The operation of determining the first weight and the second weight,
and determining a first weight and a second weight based on a ratio of pixels belonging to the flat region to all pixels and image characteristics.
According to claim 9,
The operation of determining the first weight and the second weight,
Calculating a degree of flatness of the central pixel by calculating a difference between the RGB values of the central pixel and the RGB values of the surrounding pixels; and
and determining the first weight and the second weight based on the flatness of the central pixel.

Images