摘要:
The present invention can suppress the decline in video quality during encoding. The present invention generates, for each of the nine intra image prediction modes preset according to the AVC standard, a difference image data item containing a difference value from pixels surrounding a process-target pixel. Then, an encoding device (10) ranks the intra image prediction modes depending on the sum of absolute difference (SAD), which is the sum of differences that is based on the sum of absolute values of each process-target pixel of the difference image data item and a preference order of offset[n] preset for the intra image prediction mode.
摘要:
To stop the decline of the quality of image associated with encoding. The present invention multiplies a decoding rescaling factor (RFr) possibly used in the decoding process by only a transformation matrix (D), which is scale change, to calculate a rescaling factor (RF), which is a plurality of division factors, and then calculates, for each detection unit, the sum (ΣY) of evaluation values (Y) based on a residue (r) obtained as a result of dividing an element of a DCT coefficient by a plurality of rescaling factors (RF). Moreover, the present invention compares correlations of the sum (ΣY) of the evaluation values (Y) with a plurality of rescaling factors (RF), and detects, based on the rescaling factor (RF) whose sum (ΣY) of the evaluation values (Y) is a minimum value, a quantization factor used in the previous process of encoding the input image data.
摘要:
An image processing apparatus includes: an orthogonal transforming section which performs an orthogonal transform for image data to generate a transform coefficient; and a quantization factor detecting section which detects a quantization factor used in a previous encoding process, using the transform coefficient, wherein the quantization factor detecting section independently performs a process of detecting the quantization factor from the transform coefficient generated by orthogonally transforming a luminance component of the image data and a process of detecting the quantization factor from the transform coefficient generated by orthogonally transforming a color difference component of the image data.
摘要:
The present invention enables a reduction in circuit scale.In an image coding apparatus (100), as for DCT coefficients as simple coded data obtained by coding an input image (91) by simple processing, the input image (91) is coded by at least quantizing the input image (91) as an input image on the basis of selected quantization parameters (QPl) discretely selected from quantization parameters (QP) as quantization factors, thereby computing generated code sizes of the input image (91) upon coding. The image coding apparatus (100) corrects an error in the generated code sizes of the input image upon coding which occurs in accordance with the simple processing, thereby computing low-precision generated code sizes. The image coding apparatus (100) computes low-precision generated code sizes when the input image (91) is coded on the basis of quantization parameters (QP) other than the selected quantization parameters (QPl), by an interpolation process with respect to the low-precision generated code sizes when the input image (91) is coded on the basis of the selected quantization parameters (QPl).
摘要:
The present invention enables a reduction in circuit scale.In an image coding apparatus (100), as for DCT coefficients as simple coded data obtained by coding an input image (91) by simple processing, the input image (91) is coded by at least quantizing the input image (91) as an input image on the basis of selected quantization parameters (QPl) discretely selected from quantization parameters (QP) as quantization factors, thereby computing generated code sizes of the input image (91) upon coding. The image coding apparatus (100) corrects an error in the generated code sizes of the input image upon coding which occurs in accordance with the simple processing, thereby computing low-precision generated code sizes. The image coding apparatus (100) computes low-precision generated code sizes when the input image (91) is coded on the basis of quantization parameters (QP) other than the selected quantization parameters (QPl), by an interpolation process with respect to the low-precision generated code sizes when the input image (91) is coded on the basis of the selected quantization parameters (QPl).
摘要:
The present invention enables a circuit configuration to be simplified. An image encoding device (100) receives an input image (91) that is line-scanned in units of MBs as scan blocks, each constituted by a plurality of 4×4 blocks, while being scanned in units of 4×4 blocks as encoding blocks, each constituted by a plurality of pixels. The image encoding device (100) selects a VLC (variable length) table corresponding to a table selection index nC, which is an average value of the numbers nB and nA of nonzero coefficients as encoding values on which variable-length encoding is performed in upper-adjoining and left-adjoining 4×4 blocks of a 4×4 block as an encoding target in quantization coefficients as encoding target data based on the input image (91). At this time, in a case where the 4×4 block as an encoding target is at an upper end of an MB, the image encoding device (100) equates the number nB of nonzero coefficients of the upper-adjoining 4×4 block with the number nA of nonzero coefficients of the left-adjoining 4×4 block. The image encoding device (100) performs variable-length encoding on the number of nonzero coefficients of a 4×4 block as an encoding target in quantization coefficients using the selected VLC table.
摘要:
To stop the decline of the quality of image associated with encoding. The present invention multiplies a decoding rescaling factor (RFr) possibly used in the decoding process by only a transformation matrix (D), which is scale change, to calculate a rescaling factor (RF), which is a plurality of division factors, and then calculates, for each detection unit, the sum (ΣY) of evaluation values (Y) based on a residue (r) obtained as a result of dividing an element of a DCT coefficient by a plurality of rescaling factors (RF). Moreover, the present invention compares correlations of the sum (ΣY) of the evaluation values (Y) with a plurality of rescaling factors (RF), and detects, based on the rescaling factor (RF) whose sum (ΣY) of the evaluation values (Y) is a minimum value, a quantization factor used in the previous process of encoding the input image data.
摘要:
The present invention can suppress the decline in video quality during encoding. The present invention generates, for each of the nine intra image prediction modes preset according to the AVC standard, a difference image data item containing a difference value from pixels surrounding a process-target pixel. Then, an encoding device (10) ranks the intra image prediction modes depending on the sum of absolute difference (SAD), which is the sum of differences that is based on the sum of absolute values of each process-target pixel of the difference image data item and a preference order of offset[n] preset for the intra image prediction mode.
摘要:
To predict a target code amount from a code amount calculated on a single quantizer scale. The present invention stores relationship information on a plurality of pieces of quantized data for prediction having different MB generated code amounts on a fixed quantizer scale (QI) as prediction curves, the relationship information indicating a relationship between a plurality of quantizer scales (Q) representing a plurality of quantizer steps and MB generated code amounts. The present invention quantizes image data on a macroblock-by-macroblock basis on the single fixed quantizer scale (QI) out of the predetermined plurality of quantizer scales (Q), thereby generating temporary quantized data, and calculates the MB generated code amount of each macroblock unit of this temporary quantized data. The present invention then selects a piece of quantized data for prediction from the plurality of prediction curves based on the MB generated code amount of the temporary quantized data and the fixed quantizer scale (QI), and predicts the MB generated code amounts for situations when the image data is quantized on quantizer scales (Q) not selected by a quantization selection section, based on the selected piece of quantized data for prediction.
摘要:
An image coding apparatus for coding image data. The image coding apparatus includes: a first coding mechanism predicting a quantization parameter and a quantization matrix to be used for calculating a target amount of code for the image data by coding the image data; a second coding mechanism correcting the quantization parameter predicted by the first coding means from an error between an amount of generated code produced by coding using the quantization parameter and the quantization matrix predicted by the first coding mechanism and the target amount of code; and a third coding mechanism coding the image data using the quantization parameter corrected by the second coding mechanism.