摘要:
An image processing system which compresses an image including both a binary image and a continuous tone image by a sub-band transform method with a high compression rate. A 2×2 pixel matrix block is extracted from image data. A transform factor having a plurality of frequency components is obtained from the 2×2 pixel matrix block data. The transform factor is quantized by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components.
摘要:
An image processing system which compresses an image including both a binary image and a continuous tone image by a sub-band transform method with a high compression rate. A 2×2 pixel matrix block is extracted from image data. A transform factor having a plurality of frequency components is obtained from the 2×2 pixel matrix block data. The transform factor is quantized by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components.
摘要:
A dividing portion divides input image data into a plurality of block data, a block expressed by each of said plurality of block data comprising a pixel matrix of the same predetermined size. A transform portion transforms each of the plurality of block data by a frequency transform method so as to produce a transform factor. A quantizing portion, having a plurality of quantization tables, quantizes the transform factor using one of the plurality of quantization tables. An encoding portion encodes an output of the quantizing portion. A reverse transform portion restores image data from the output of the quantizing portion. A measuring portion measures an error between the input image data and the image data restored by the reverse transform portion. The quantizing portion quantizes the transform factor again using another one of the plurality of quantization tables when the error measured by the measuring portion exceeds a predetermined threshold value.
摘要:
An image processing apparatus for inputting image data from an external image input device and outputting the inputted image data to an external image output device after processing the data, the image processing apparatus including a data compression device for compressing the inputted image data by a variable-length data compression method. An image data storing device stores the inputted image data therein. A control device controls the apparatus, such that, when a size of an output image of the inputted image data is larger than a predetermined size, the data compression device compresses the inputted image data by the variable-length data compression method and the image data storing device stores the compressed image data therein, and, when the output image of the inputted image data is equal to or smaller than the predetermined size, the image data storing device stores the inputted image data therein without data compression.
摘要:
A device for processing images includes a compressing/coding unit which encodes image data including a plurality of color components to produce fixed-length codes, a memory unit which stores therein the codes produced by the compressing/coding unit, a distribution-measurement unit which measures a distribution of the color components concurrently with the encoding of the image data performed by the compressing/coding unit, and a memory-control unit which releases a memory space assigned to part of the codes relating to colors in the memory unit if the distribution-measurement unit detects that the distribution concentrates on a particular color composition, and records data indicative of the particular color composition in the memory unit.
摘要:
A coding apparatus which can simplify a coding circuit and also simplify the processing of quantization. Image data that consists of R-, G-, and B-color components read from a scanner into buffers is subjected to transformation using a position correlation for each of RGB in position-correlation transformation sections. The DC component of each of the components is then color-converted in a color conversion section to be a DC lightness signal and DC color signals, and the signals are quantized in a quantization section and a coding section. Whereas, the AC components of each of the components are subjected to quantization in a first step in an AC component quantization section, and further to color conversion in a color conversion section to be an AC lightness signal and AC color signals. The signals are quantized in a second step in a quantization section and a coding section.
摘要:
An image processing system which compresses an image including both a binary image and a continuous tone image by a sub-band transform method with a high compression rate. A 2×2 pixel matrix block is extracted from image data. A transform factor having a plurality of frequency components is obtained from the 2×2 pixel matrix block data. The transform factor is quantized by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components.
摘要:
An image processing system which compresses an image including both a binary image and a continuous tone image by a sub-band transform method with a high compression rate. A 2×2 pixel matrix block is extracted from image data. A transform factor having a plurality of frequency components is obtained from the 2×2 pixel matrix block data. The transform factor is quantized by a fixed-length quantizing method by deleting a predetermined number of lower order bits of each of the frequency components.
摘要:
An image processing apparatus includes a converter, a calculator and a reverse converter. The converter performs a frequency conversion operation on a color image signal which includes a brightness signal and color signals and divides values of each of the brightness signal and the color signals into high frequency coefficients and a low frequency coefficient. The calculator calculates the high frequency coefficients of the brightness signal and the color signals, generates a set of different high frequency coefficients, and produces a new brightness signal by adding the low frequency coefficient of the brightness signal to the set of different high frequency coefficients. The reverse converter performs a reverse frequency conversion operation on the new brightness signal.
摘要:
An image data encoding apparatus includes a wavelet transform unit which produces a first subband coefficient and a second subband coefficient as an output in response to each of blocks of the input image data, the first and second subband coefficients being produced by performing a multiple decomposition process in which only the first subband coefficient is further decomposed. A first text transform unit produces an intensity coefficient of a first kind as well as a set of coefficients of a second kind as an output in response to each block, the intensity coefficient including significant bits, and only the intensity coefficient being further decomposed in the first text transform unit. A second text transform unit produces a set of coefficients of the second kind as an output in response to each block, one of the coefficients of the second kind including significant bits but not being further decomposed. A selector selects one of the output of the wavelet transform unit, the output of the first text transform unit and the output of the second text transform unit, as an input to an entropy coder, in accordance with a combination of an area-discriminating signal and a text-transform control signal.