4746 results about "Compression ratio" patented technology

By utilizing parameters derivable from a compressed bit-stream, measures are obtained of the subjective quality of a decoded picture, without the necessity for reference to source material. A blockiness measure is derived both locally and globally and used to control a de-blocking filter. An estimate of signal-to-noise ratio is derived from quantization values.

The present invention provides a method for transmission of a images and/or video over bandwidth limited transmission channels having varying available bandwidth, which method comprises the use of a classification algorithm for decomposing the images and/or video to be transmitted into multiple spatial areas, each area having a specific image type; detecting the image type of each of those areas separately selecting for each of those areas an image and/or video encoding algorithm having a compression ratio. The classification algorithm prioritizes each of the areas, the classification algorithm increasing the compression ratio of the image and/or video encoding algorithm dedicated to spatial areas having lower priority in case of decreasing bandwidth.

Output control system and method includes calculating gain for an input signal, detecting a predetermined condition, and modifying the gain calculation in accordance with one or more kneepoints to provide a varying output signal. A companding ratio is then established in accordance with the kneepoints. System gain is then adjusted, and the companding ratio may be further adjusted by adjusting one of the kneepoints relative to another.

Fuel management system for efficient operation of a spark ignition gasoline engine. Injectors inject an anti-knock agent such as ethanol directly into a cylinder of the engine. A fuel management microprocessor system controls injection of the anti-knock agent so as to control knock and minimize that amount of the anti-knock agent that is used in a drive cycle. It is preferred that the anti-knock agent is ethanol. The use of ethanol can be further minimized by injection in a non-uniform manner within a cylinder. The ethanol injection suppresses knock so that higher compression ratio and/or engine downsizing from increased turbocharging or supercharging can be used to increase the efficiency of the engine.

Compressed memory systems and methods that reduce problems of memory overflow and data loss. A compression engine compresses blocks of data for storage in a compressed memory. A compression monitor monitors the achieved compression ratio and provides a software trap when the achieved compression ratio falls below a minimum. After the trap is provided software monitors the fill state of the compressed memory. If the compressed memory is approaching full, the software changes the block size to improve the compression ratio.

A method for coding an RGB color space signal is disclosed. In accordance with the method, a base plane is encoded using an independent mode, and an enhanced plane is encoded by referring to the base plane without converting the RGB color space signal into YCbCr color space signal to reduce a redundancy between RGB planes and improve a compression ratio of an image.

The invention provides an electrocardiogram signal compression and de-compression system. The invention uses the sign characteristics of the coefficients of the discrete cosine transform type IV and the characteristics of quantization of spectrum to perform the differential pulse code modulation of the spectrum for preserving the high frequency characteristics of the spectrum of the discrete Fourier transform. The invention also uses the Huffman coding to increase the compression ratio. Different from the conventional compression technology, the invention uses the fact that the quantization values of the spectrum in the high frequency are almost the same to increase the compression ratio and preserve the characteristics of high frequency components of the spectrum.

This invention relates to methods of feature extraction from MPEG-2 and MPEG-4 compressed video sequences. The spatio-temporal compression complexity of video sequences is evaluated for feature extraction by inspecting the compressed bitstream and the complexity is used as a descriptor of the spatio-temporal characteristics of the video sequence. The spatio-temporal compression complexity measure is used as a matching criterion and can also be used for absolute indexing. Feature extraction can be accomplished in conjunction with scene change detection techniques and the combination has reasonable accuracy and the advantage of high simplicity since it is based on entropy decoding of signals in compressed form and does not require computationally expensive inverse Discrete Cosine Transformation (DCT).

The present invention relates to systems and methods for efficient bit rate alteration of a bitstream to match an available channel capacity. The efficient bit rate alteration includes selective re-quantization of the compressed bitstream. Selective re-quantization according to the present invention applies multiple re-quantization schemes to different portions of a bitstream. In one embodiment, the multiple re-quantization schemes each have a different computational load. By selectively choosing which type of re-quantization is performed on each portion, efficient bandwidth scaling and data transmission may be achieved both when computational capacity is limited and when video data integrity is important.

A data compression system that dynamically adapts the degree of compression used in response to the priority of the data to be compressed is provided by virtue of one embodiment of the present invention. In one embodiment, only low priority data is compressed while high priority data is passed through to the network in uncompressed form. Also, the compression ratio can be varied depending on the priority of the data to allocate a larger portion of available bandwidth to higher priority traffic while imposing greater compression related delay on lower priority traffic.

An enhancement that reduces the digital interface rate of analog-to-digital (A/D) and digital-to-analog (D/A) converters through the use of compression and decompression is described. The present invention improves A/D converters by compressing the sampled version of the A/D converter's analog input signal in real time, thereby significantly decreasing the required bit rate of the A/D converter's digital interface. Similarly, the present invention improves D/A converters by decreasing the required bit rate of the D/A converter's digital interface. D/A converters enhanced by the present invention include a decompressor that decompresses the D/A converter's compressed digital input in real time, prior to conversion to an analog output signal. The present invention's simplicity and its ability to be implemented using multiple compression and decompression elements allow its use in A/D and D/A converters with arbitrarily high sampling rates. By selecting a desired compression ratio during lossy compression, users of the present invention can precisely control the bit rate of the A/D and D/A converter's digital interface. Users of the present invention can dynamically choose the desired balance between the quality and the bit rate of A/D and D/A converters by adjusting various compression and decompression control parameters.

A method of amplification includes amplifying an input signal with a predetermined or user adjustable maximum gain to produce a second signal and compressing the dynamic range of the second signal with an automatic gain control to produce an output signal. The compression ratio of the automatic gain control is greater than one for output signals below a predetermined threshold output signal level and is essentially one for output signals above the predetermined threshold output signal level. The compression ratio may be predetermined or the method may include determining the compression ratio of the automatic gain control. The compression ratio may be determined according to the amplitude of the output signal or according to an input-output curve. The input-output curve my be predetermined and may be selected according to the auditory needs of a listener. Preferably the input-output curve is determined according to the predetermined or user adjustable maximum gain.

The method includes steps: first at encoding end, obtaining distribution of image energy on time and frequency domain through discrete wavelet transform; based on correlation between wavelet coefficient, wavelet coefficient in each order is divided according to tree structure; SPIHT encoding is carried out for wavelet coefficient of each tree; encoding result is deposited on encoding end momentarily; finally, results of encoding each tree are synthesized as a code stream in use for storing or transferring. The invention realizes video compression in high compression ratio and low degree of distortion by using less memory space, particular suitable to dedicated system realized through hardware.

An improved method, system, and a computer program storage device (e.g., including software embodied on a magnetic, electrical, optical, or other storage device) for management of compressed main memory allocation and utilization which can avoid system abends or inefficient operation that would otherwise result. One feature reduces (and ultimately eliminates) all unessential processing as the amount of available storage decreases to a point low enough to threaten a system abend. In another example, the amount of current memory usage is determined as well as one or more of: an estimate of an amount of allocated but unused memory; a determination of the amount of memory required for outstanding I/O requests. The compressed memory is managed as a function of the current memory usage and one or more of the other measured or estimated quantities. The compressed memory can be managed by maintaining a set of dynamic thresholds; estimating the amount of storage that can easily be freed (used but available) and the amount of storage that is committed (allocated but unused). The estimate of committed storage can include: the current storage utilization; and an estimate of storage committed to new pages (based on the number of new pages granted), the times at which this was done, the estimated compression ratio, and estimates of residency times in the cache.

A valvetrain system mechanization for an internal combustion engine using compression ignition, including homogeneous charge compression ignition, having two intake and one or more exhaust valves per cylinder. The valves are operated by dual overhead camshafts having two-step cams. The intake and exhaust camshafts are provided with phasers for varying the opening and closing of the intake and exhaust valves. A two-step roller finger follower is disposed for each valve between the cam lobes and the valve stem. The two sets of intake and exhaust valves are controlled by separate oil control valves. Swirl of gases may be introduced by mismatching the lifts of the valves. The valve opening times, closing times, lifts, fuel injection, compression ratio, and exhaust gas recirculation may be varied to optimize combustion conditions for a range of engine operating modes.

A hardware accelerator for improving the decompression performance when decompressing data in Lempel-Ziv-Huffman compressed data format. The use of a Huffman encoding second stage in the popular and widely-used Lempel-Ziv-Huffman standard improves the compression ratio but complicates the decompression, because the Huffman encoding is applied selectively only to certain parts of the Lempel-Ziv tokens, and thus Huffman decoding must also be applied selectively during decompression. The present invention features a variable-length token decoder which is able to selectively decode the Huffman-encoded portions of the compressed data, and therefore enables high-performance decompression for compressed data having a very good compression ratio. Such an accelerator is well-suited for use in data processors which are to be loaded with pre-compressed data and software applications, particularly those employing flash memory.

A system for chilling the pressurized charge air to a reciprocating engine is disclosed wherein the chilling is provided by a thermally activated refrigeration cycle powered by waste heat from the engine system. This reduces the required compression power, and also retards knock, making higher compression ratios possible. The chilling system is designed to minimize the amount of chilling required, and also to enable use of compression heat to power the chiller. The disclosed improvement also accommodates exhaust gas recirculation, plus providing activation heat from the exhaust gas, plus Miller cycle timing of the intake valves. Referring to FIG. 1, the charge air from turbocharger 5 is cooled in three stages: heat recovery stage 10; ambient-cooled stage 11; and chilling stage 12. Condensed moisture is removed from the charge air by valve 14 before the charge is supplied to inlet manifold 2.

The present invention provides a very flexible, digital system for capturing and storing panoramic images using progressive scan (that is, non interlaced) technology. The system includes a digital image input device and an associated control computer. Since the image capture device is digital it can be easily and flexibly controlled by software in the control computer. The image input device has six lenses positioned on the six faces of a cube. While the image input system can have other lens configurations, the use of six lenses in a cubic configuration is optimal for a system that is used to capture a spherical panorama. The six lenses simultaneously focuses different images on six CCDs (Charge Coupled Devices). The image input device also includes an embedded controller, and data compression circuitry. The embedded controller controls the exposure time of the CCDs (i.e. the effective aperture and effective shutter speed) and reads image data from the CCDs. The image data read from the CCDs is compressed, multiplexed, and sent to the control computer. The control computer stores the images in frames, each of which have one image from each of the six lenses. Each frame includes six images that were simultaneously recorded and any associated information, such as audio tracks, textual information, or environmental information such as GPS (Global Position System) data or artificial horizon data. The control computer includes a user interface which allows a user to specify control information such as frame rate, compression ratio, gain, etc. The control computer sends control information to the embedded controller which in turn controls the CCDs and the compression circuitry. The images can be sent from the control computer to a real time viewer so that a user can determine if the correct images are being captured. The images stored at the control computer are later seamed into panoramas and made into panoramic movies.