Abstract: A method for performing an encrypted voice call between a first terminal and a second terminal supporting a Voice over Internet Protocol (VoIP)-based voice call. In the method, the first and second terminals generate and store a bio key using biographical (bio) information of a user in advance before performing a voice call, the first terminal sends a request for a voice call to the second terminal and establishing a session, the first and second terminals exchange and store a bio key stored in each terminal, and the first and second terminals generate a session shared key using the exchanged bio key and starting a Secure Real-time Transport Protocol (SRTP) session, and a restored bio key by acquiring bio information from received data. User authentication is then performed by comparing the bio key with the restored bio key.

Abstract: A system and method for video quality assessment includes utilizing codec auxiliary information related to the encoding and decoding process to enhance performance of picture quality assessment. In a video transmission system, video quality assessment can be accurately performed in real time with reduced computational load upon the client. In particular, the server performs first picture quality assessment and sends the assessment result to the client, and the client performs second picture quality assessment only when a transmission error occurs to reduce the computational load on the client.

Abstract: A method for setting an output bit rate for video data transmission in a WiBro system in which an uplink state value for a predetermined unit time is calculated to determine an uplink network state of the predetermined unit time. An average of uplink state values for a predetermined number of unit times is calculated, and a video encoding bit rate is increased if the average of the uplink state values is larger than a predetermined first threshold. However, the video encoding bit rate is decreased if the average of the uplink state values is less than a predetermined second threshold.

Abstract: Disclosed is a method for detecting a scene change in real time in order to control a moving-picture encoding data rate, the method including: dividing a current frame into a plurality of regions, and calculating a dissimilarity metric (DM) of each divided region; determining if the dissimilarity metric of each divided region is beyond a preset reference value; calculating the number of regions, the dissimilarity metric of which is beyond the preset value, in the current frame; and determining that a scene change occurs in the current frame, when the number of regions, the dissimilarity metric of which is beyond the reference preset value, is equal to or greater than a preset threshold value.

Abstract: Disclosed is a method for controlling bit rates in consideration of wireless channel environment by an apparatus that transmits and receives moving picture encoding data via a wireless network. The apparatus for transmitting/receiving data through a wireless communication network connected to the apparatus including a channel state analyzing unit for analyzing a wireless channel environment, an encoding controller for generating control information containing information about a quantization parameter, skip or non-skip of frames indication, frame type indication, and use or non-use of an Error Resilient Tool (ERT) indication, in consideration of an analyzation result received from the channel state analyzing unit, a moving picture encoding unit for encoding incoming moving picture data, based on the control information received from the encoding controller; and a data transmitting/receiving unit for transferring the encoded moving picture data through the wireless channel to an exterior.

Abstract: A cross-layer optimization method for controlling a bit rate of a video coder/decoder (codec) in video data transmission for wireless devices such as a wireless broadband (WiBro) system terminal that adapts to changing transmission/reception characteristics and usage. The method typically includes checking, by a sender, radio channel state information of a sender side and a receiver side; determining, by the sender, a transmission bit rate of a video codec by using the radio channel state information of the sender side; and adjusting, by the sender, the transmission bit rate of the video codec by using the radio channel state information of the receiver side when a communication network used by a receiver typically based on the type of a communication network being used by the sender.

Abstract: Disclosed are a wavelet transformation-based image encoder, decoder and method for generating a thumbnail image. In the present invention, an original image is tiled according to a preset tiling scheme, and wavelet transformation is performed for each tiled image. An LL image is extracted from the tiled image and range mapping is performed for the color values of each pixel of the extracted LL images. After the range mapping of the color values according to the pixels, a thumbnail image is generated by reconstructing the LL images according to the predetermined tiling scheme. According to the present invention as described above, when an encoder using a wavelet transformation method encodes the original image into a wavelet image or a decoder using wavelet transformation method decodes the wavelet encoded image into the original image, the thumbnail image can be easily generated.

Abstract: Methods and apparatus for video frame rate conversion are disclosed. In one aspect of the invention, a basic interpolation motion vector for an interpolated frame is generated using a motion vector of a current frame. The motion vector of the current frame is compared with a motion vector of a previous frame. The basic interpolation motion vector is offset and corrected according to a comparison result. The interpolated frame is generated by performing motion compensation using at least one of the basic interpolation motion vector and the corrected basic interpolation motion vector.

Abstract: Disclosed is an intelligent display method for a multimedia mobile terminal. The method includes the steps of determining a type of a camera shot existing in a sport game video; deciding a region of interest within an image frame of the sport game video when it has been determined that the camera shot is a long-distance shot, magnifying the region of interest, and displaying the region of interest on the mobile terminal, and displaying the entire image frame on the mobile terminal when it has been determined that the video shot is a non-long-distance shot. The method enables the user to watch images in a more understandable and comfortable manner.

Abstract: An apparatus and method is provided for outputting a natural color image in a mobile terminal. The apparatus and method includes a color sensor to measure light quantity and color information of the surrounding environment, and a memory to store color information of a source image to be output to the display unit. A controller is provided and calculates color information in which a complementary color component of color information output from the color sensor is stressed based on the color information output from the color sensor, complements the color information of the source image stored in the memory with the color information in which the complementary color component is stressed, and outputs the complemented color information to the display unit.

Abstract: An apparatus and method for synthesizing images captured by a mobile terminal with a camera to generate a panorama image. A first memory stores a first captured image in panorama mode for synthesizing captured images. A second memory stores captured images subsequent to the first captured image. The images stored in the first and second memories are compared and synthesized. When a difference value between the compared images is less than a threshold value, a synthesized image is stored in the first memory.