Abstract: A device for data compression includes a domain transformer unit, a classifying unit, a variable length encoder, a fixed length encoder and a memory unit. The domain transformer unit transforms time-domain data into frequency-domain data. The classifying unit determines an encoding type of the frequency-domain data based on occurrence probability of the frequency-domain data. The variable length encoder encodes first frequency-domain data that are determined to be encoded by variable length coding. The fixed length encoder encodes second frequency-domain data that are determined to be encoded by fixed length coding. The memory unit stores the encoded first and second frequency-domain data by relocating the encoded first and second frequency-domain data such that the encoded first frequency-domain data are placed adjacently and the encoded second frequency-domain data are placed adjacently. Therefore, the time for decoding the corresponding data may be reduced.

Abstract: A contrast control apparatus includes a memory for storing input image signals within one frame and an image reducing unit for selecting at least one image signal of the input image signals. An accumulation value calculating unit calculates accumulation values for predetermined sampling gray values with respect to the selected image signal. An image characteristic decision unit determines at least one characteristic of the selected image based on the accumulation values. A contrast control function calculating unit calculates a contrast control function based on the characteristic of the selected image. A contrast controller controls contrast of the image signals stored in the memory according to the contrast control function.

Abstract: A method of changing a pixel color includes determining whether a chrominance of a pixel is in a preference chrominance area, where the preference chrominance area is defined as a conic section in a two-dimensional chrominance plane and an eccentricity of the conic section is not greater than 1, and changing the chrominance of the pixel to a preference chrominance to generate a preference pixel when the chrominance of the pixel is in the preference chrominance area. Therefore, the method may set a preference chrominance area in a simple manner, and hardware for setting the preference chrominance area may be easily implemented.

Abstract: A touch panel device and a method for detecting a contact position are provided. The touch panel device includes a touch panel including a first touch pattern, the first touch pattern having a plurality of first touch pads connected in series; and a touch sensor for applying a clock signal to one terminal of the first touch pattern, receiving a first delayed clock signal from the other terminal of the first touch pattern, and generating contact position data corresponding to a contact position of an object using a difference in delay time between the clock signal and the first delayed clock signal. Thus, since the plurality of touch pads are connected in series, the contact position of the entire touch panel can be sensed with only one touch sensor, and the touch pad has a greater area than the connection line for a distinguished difference in resistance between the touch pad and the connection line, such that the contact position can be accurately detected.

Abstract: A variable-length decoder includes a bitstream interface unit and a decoding unit. The bitstream interface unit generates a decoding bitstream for a current decoding process based on an unused decoding bitstream and an input bitstream. The unused bitstream includes unused bits of a previous decoding bitstream. The decoding unit decodes the decoding bitstream to generate a plurality of symbols per clock cycle and provides a next unused bitstream for a next decoding process to the bitstream interface unit.

Abstract: A contrast control apparatus includes a memory for storing input image signals within one frame and an image reducing unit for selecting at least one image signal of the input image signals. An accumulation value calculating unit calculates accumulation values for predetermined sampling gray values with respect to the selected image signal. An image characteristic decision unit determines at least one characteristic of the selected image based on the accumulation values. A contrast control function calculating unit calculates a contrast control function based on the characteristic of the selected image. A contrast controller controls contrast of the image signals stored in the memory according to the contrast control function.

Abstract: A method of changing a pixel color includes determining whether a chrominance of a pixel is in a preference chrominance area, where the preference chrominance area is defined as a conic section in a two-dimensional chrominance plane and an eccentricity of the conic section is not greater than 1, and changing the chrominance of the pixel to a preference chrominance to generate a preference pixel when the chrominance of the pixel is in the to preference chrominance area. Therefore, the method may set a preference chrominance area in a simple manner, and hardware for setting the preference chrominance area may be easily implemented.

Abstract: A variable-length decoder includes a bitstream interface unit and a decoding unit, The bitstream interface unit generates a decoding bitstream for a current decoding process based on an unused decoding bitstream and an input bitstream. The unused bitstream includes unused bits of a previous decoding bitstream. The decoding unit decodes the decoding bitstream to generate a plurality of symbols per clock cycle and provides a next unused bitstream for a next decoding process to the bitstream interface unit.

Abstract: A device for data compression includes a domain transformer unit, a classifying unit, a variable length encoder, a fixed length encoder and a memory unit. The domain transformer unit transforms time-domain data into frequency-domain data. The classifying unit determines an encoding type of the frequency-domain data based on occurrence probability of the frequency-domain data. The variable length encoder encodes first frequency-domain data that are determined to be encoded by variable length coding. The fixed length encoder encodes second frequency-domain data that are determined to be encoded by fixed length coding. The memory unit stores the encoded first and second frequency-domain data by relocating the encoded first and second frequency-domain data such that the encoded first frequency-domain data are placed adjacently and the encoded second frequency-domain data are placed adjacently. Therefore, the time for decoding the corresponding data may be reduced.

Abstract: Method and apparatus for controlling the light power of an optical disk system, and optical disk system having the same are provided. The optical disk system includes a microcontroller for controlling the operation of the optical disk system, a light power adjusting apparatus for generating a light quantity control signal for controlling the quantity of light emitted from the optical disk, and an optical pickup device for adjusting the quantity of light emitted from the optical disk in response to the light quantity control signal.

Abstract: A control apparatus and method for controlling a velocity of a spindle motor included in an optical disk reproducing system to prevent a forward or backward overrun of a spindle motor are disclosed. A widest signal detector of the apparatus detects the widest pulse width of an eight-to-fourteen modulation (EFM) signal according to a main clock signal and generates a first status signal representing a status of the pulse width of the detected signal according to a frame clock signal, which is divided by a first predetermined number j. A narrowest signal detector of the apparatus generates a second status signal representing a status of the narrowest pulse width of the first status signals according to the frame clock signal divided by a second predetermined number k, where k is greater than j. An overrun controller increases or decreases or holds a previously counted result according to the frame clock signal divided by the second predetermined number and the second status signal.