Patents
Literature
Patsnap Copilot is an intelligent assistant for R&D personnel, combined with Patent DNA, to facilitate innovative research.
Patsnap Copilot

414 results about "Gain correction" patented technology

Methods and Devices for Low-Frequency Emphasis During Audio Compression Based on Acelp/Tcx

A first aspect of the present invention relates to a method for low-frequency emphasizing the spectrum of a sound signal transformed in a frequency domain and comprising transform coefficients grouped in a number of blocks, in which a maximum energy for one block is calculated and a position index of the block with maximum energy is determined, a factor is calculated for each block having a position index smaller than the position index of the block with maximum energy the calculated maximum energy and the energy of the block, and, for each block, a gain determining from the factor is applied to the transform coefficients of the block. Another aspect of the invention is concerned with an HF coding method for coding, through a bandwidth extension scheme, an HF signal obtained from separation of a full-bandwidth sound signal into the HF signal and a LF signal, in which an estimation of the an HF gain is calculated from LPC coefficients, the energy of the HF signal is calculated, the LF signal is processed to produce a synthesized version of the HF signal, the energy of the synthesized version of the HF signal is calculated, a ratio between the energy of the HF signal and the energy of the synthesized version of the HF signal is calculated and expressing as an HF gain, and a difference between the estimation of the HF gain and the HF gain is calculated to obtain a gain correction. A third aspect of the invention is concerned with a method for producing from a decoded target signal an overlap-add target signal in a current frame coded according to a first coding mode. According to this method, the decoded target signal of the current frame is windowed and a left portion of the window is skipped. A zero-input response of a weighting filter of the previous frame coded according to a second coding mode is calculated and windowed so that the zero-input response has an amplitude monotonically decreasing to zero after a predetermined time period. Finally, the calculated zero-input response is added to the decoded target signal to reconstruct the overlap-add target signal.
Owner:VOICEAGE CORP

Methods and devices for low-frequency emphasis during audio compression based on ACELP/TCX

A first aspect of the present invention relates to a method for low-frequency emphasizing the spectrum of a sound signal transformed in a frequency domain and comprising transform coefficients grouped in a number of blocks, in which a maximum energy for one block is calculated and a position index of the block with maximum energy is determined, a factor is calculated for each block having a position index smaller than the position index of the block with maximum energy the calculated maximum energy and the energy of the block, and, for each block, a gain determining from the factor is applied to the transform coefficients of the block. Another aspect of the invention is concerned with an HF coding method for coding, through a bandwidth extension scheme, an HF signal obtained from separation of a full-bandwidth sound signal into the HF signal and a LF signal, in which an estimation of the an HF gain is calculated from LPC coefficients, the energy of the HF signal is calculated, the LF signal is processed to produce a synthesized version of the HF signal, the energy of the synthesized version of the HF signal is calculated, a ratio between the energy of the HF signal and the energy of the synthesized version of the HF signal is calculated and expressing as an HF gain, and a difference between the estimation of the HF gain and the HF gain is calculated to obtain a gain correction. A third aspect of the invention is concerned with a method for producing from a decoded target signal an overlap-add target signal in a current frame coded according to a first coding mode. According to this method, the decoded target signal of the current frame is windowed and a left portion of the window is skipped. A zero-input response of a weighting filter of the previous frame coded according to a second coding mode is calculated and windowed so that the zero-input response has an amplitude monotonically decreasing to zero after a predetermined time period. Finally, the calculated zero-input response is added to the decoded target signal to reconstruct the overlap-add target signal.
Owner:VOICEAGE CORP

Display uniformity calibration system and method for a staring forward looking infrared sensor

A method and system for maintaining uniformity in a FLIR display. During a one-time initialization procedure, a plurality of dynamic ranges are defined by covering a specific range of bucket fill levels when in a certain gain. To cover all dynamic ranges possible, a plurality of pairs of responsivity equalization (RE) calibrations (each pair producing a RE set of pixel gain corrections) are also accomplished in the same one time initialization period. A plurality of corresponding level equalization (LE) calibrations (each using the appropriate calibrated RE set and producing a LE set of pixel level corrections) for each anticipated dynamic range are made at every power-up initialization. Each of the calibrations is done with respect to a thermal reference source to produce a uniform scene at the desired bucket fill level. An algorithm is employed which forces the two bucket fill points defined during the responsivity calibration to span as far as possible the dynamic range and forces the level equalization bucket fill point to fall within the two bucket fill points of the responsivity calibration. Then, during an operational time period, the scene and optics temperatures are monitored, and if the average bucket fill value exceeds the bucket fill range of the present dynamic range, the presently selected dynamic range is changed to a second dynamic range (gain is changed along with the RE set and LE set). The dynamic ranges are designed to overlap so that a hysteresis effect is achieved. The pre-calibrations and automatic dynamic range switching prevent saturation and create the best uniformity (lowest fix pattern noise) possible while allowing for continuous operation of the FLIR system, thus eliminating the interruption caused by the prior art touch-up calibration procedure.
Owner:RAYTHEON CO

Filter coefficient calculation device, filter coefficient calculation method, control program, computer-readable storage medium, and audio signal processing apparatus

In a filter coefficient calculation device according to the present invention, a gain correction characteristic calculation section calculates impulse responses corresponding to a linear-phase filter having an inverse characteristic of a gain characteristic of a reproduction system, and calculates, as a gain correction characteristic, a frequency characteristic of continuous-time impulse responses that include a peak value, the continuous-time impulse responses being impulse responses, clipped from the calculated impulse responses, whose number is identical to the preset number of filter taps. Moreover, a phase correction characteristic calculation section calculates a phase correction characteristic by normalizing, from an inverse characteristic of a frequency characteristic of the reproduction system, a gain characteristic of the inverse characteristic, and a filter coefficient calculation section calculates, as filter coefficients of the reproduction characteristic correction filter, filter coefficients of a filter having a synthetic correction characteristic obtained by combining the gain correction characteristic with the phase correction characteristic. This makes it possible to correct acoustic characteristics with high accuracy even in cases where the number of taps is limited.
Owner:SHARP KK
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products