55 results about "Inverse discrete cosine transformation" patented technology

A decoding apparatus comprises a variable length decoder that decodes zero-run length and nonzero coefficient, an inverse quantizer that inverse-quantizes the nonzero coefficient, a zero-run reconstruction processor that reconstruct zero coefficients, a FIFO memory that store the zero-run length data and nonzero coefficients, an inverse discrete cosine transformer that subjects the coefficients to an inverse discrete cosine transformation, and a motion compensator that subjects the transformed result to a motion compensation.

A decoding apparatus comprises a variable length decoder that decodes zero-run length and nonzero coefficient, an inverse quantizer that inverse-quantizes the nonzero coefficient, a zero-run reconstruction processor that reconstruct zero coefficients, a FIFO memory that store the zero-run length data and nonzero coefficients, an inverse discrete cosine transformer that subjects the coefficients to an inverse discrete cosine transformation, and a motion compensator that subjects the transformed result to a motion compensation.

An image processing apparatus comprises a central processing unit (CPU) and a graphics processing unit. The CPU comprises a first table specification, a second table specification, an inverse discrete cosine transformation (IDCT) module, a color space converting module and an entropy decoder. The entropy decoder retrieves and processes input image data as a two-dimensional quantized image according to the first table specification. The graphics processing unit performs a dequantizing operation on the input image data according to the second table specification. The IDCT module performs an IDCT operation on the dequantized input image data. The color space converting module performs a color space conversion on the input image data and outputs the converted image data.

The invention provides a network image copyright real-time distinguishing method. Copyright protection is necessary for digital images during network communication, but the existing robust digital watermarking technology can not achieve the real-time copyright distinguishing. The method comprises the following steps: partitioning an original image to sub-blocks which are not overlapped with each other at an embedded end; processing each sub-block by discrete cosine transformation; generating a feature watermark by comparing the DC coefficient of each sub-block with the average DC coefficient of all sub-blocks; encrypting the Logistic chaotic sequence of the feature watermark; adjusting the magnitudes of two low-frequency coefficients of the discrete cosine transformation of each sub-blockand self-embedding the encrypted feature watermark; and processing each sub-block by inverse discrete cosine transformation to obtain images with watermarks. The method has high robustness to attack.Substantially, the method provided by the invention can achieve complete blind detection by combining the self-embedding encrypted feature watermark with watermark blind extraction and authentication, thereby achieving real-time copyright distinguishing of network images.

An MPEG video decoding method and an MPEG video decoder are provided. The method includes determining whether to perform motion compensation on motion-vector-decoded data or not depending on a value of a decoded motion vector, determining whether to perform inverse discrete cosine transformation (IDCT) on motion-compensated data or not depending on values of decoded DCT coefficients, and generating a decoded image based on the results of the two determinations.

The invention discloses an MPEG multi-format compatible decoding method based on software and hardware coprocessing and a device thereof. The device comprises a processor and a hardware accelerator, wherein a register configuration interface between the processor and the accelerator supports the MPEG-1 / 2 / 4 standard. The hardware accelerator comprises a sub-pixel interpolation module, a discrete cosine inverse transformation module, a motion compensation module and a DMA controller module, wherein the sub-pixel interpolation module is used for carrying out sub-pixel interpolation operation to read-in reference macro block data; the discrete cosine inverse transformation module is used for carrying out two-dimensional discrete cosine inverse transformation treatment on residual data; the motion compensation module is used for reconstructing a decoding macro block by a sub-pixel interpolation operation result and treated residual data; and the DMA controller module is used for calculating the reference block data reading position, reading the reference block data from a reference frame and writing the reconstructed macro block into the corresponding position address of a reconstructed frame. The invention realizes MPEG multi-format compatible decoding.