摘要:
An apparatus and a method for compressing a picture by wavelet transform and entropy coding, in which the processing load of arithmetic coding may be relieved and rate control may be carried out effectively, while still maintaining the picture quality. An encoding object prediction unit predicts bitplanes to be encoded and extracts only those bitplanes which are to be encoded. An EBCOT unit generates an encoding pass from one bitplane to be encoded to another to execute arithmetic coding. In controlling the code volume to a target code volume, a rate controller sums the arithmetic codes in a sequence from the arithmetic code with the highest bit position in the totality of the code blocks of an input picture to the arithmetic code of the lowermost bit, from one bitplane to another or from one encoding pass to another, and halts the summation when the predetermined target code volume is exceeded.
摘要:
JPEG-2000 data is formatted into RTP packets for transmission through the Internet. A priority field is provided in the format, and a value indicating the importance of a code stream included in a packet is stored therein. A type field indicates a payload type of a JPEG-2000 code stream. An mh_id field is provided as an identifier of a main header of the JPEG-2000 code stream and indicates a change in the main header. An mh_length field indicates the length of the main header and a fragment offset field stores the number of offset bytes from the start of an image of the packet.
摘要:
An apparatus and a method for compressing a picture by wavelet transform and entropy coding, in which the processing load of arithmetic coding may be relieved and rate control may be carried out effectively, while still maintaining the picture quality. An encoding object prediction unit predicts bitplanes to be encoded and extracts only those bitplanes which are to be encoded. An EBCOT unit generates an encoding pass from one bitplane to be encoded to another to execute arithmetic coding. In controlling the code volume to a target code volume, a rate controller sums the arithmetic codes in a sequence from the arithmetic code with the highest bit position in the totality of the code blocks of an input picture to the arithmetic code of the lowermost bit, from one bitplane to another or from one encoding pass to another, and halts the summation when the predetermined target code volume is exceeded.
摘要:
In an image encoder (1), a quantizer (11) makes a quantization-step size set for each of low-frequency subbands whose resolution level belongs to a predetermined resolution level coincide with a quantization-step size set for each subband to encode an original image having the resolution level as it is. A low-pass rate controller (17) provides a rate control for the bit rate of arithmetic code D16 in all code blocks in a low-frequency subband to be less than a predetermined target bit rate. A high-pass rate controller (18) provides such a rate control that the bit rate of arithmetic code D17 in all code blocks in other subbands than the low-frequency subbands will be less than a target bit rate, that is, a bit rate resulted from subtraction of a bit rate D18 having actually occurred in the low-frequency subbands from a final target bit rate.
摘要:
An image coding device for reducing flicker noise in moving image coding based on Motion JPEG-2000, which applies wavelet transform to an input image, quantizes the wavelet transform coefficients, and replaces quantization coefficients of adjacent frames in accordance with a predetermined judgment condition. The device spreads the finally output quantization coefficients into bit-planes from the MSB to LSB, generates coding passes in each bit-plane, performs arithmetic coding in the coding passes, controls the code quantity to a target code quantity from the generated arithmetic codes, and generates a packet of the image data by attaching a header to the arithmetic codes. The quantization coefficients are replaced based on a difference of absolute values of the quantization coefficients at the same sub-band in the adjacent frames. By further adding the wavelet transform coefficients, erroneous detection in the substitution processing can be decreased and the flicker noise can be suppressed effectively. Also, an image coding method for the same.
摘要:
A card issuing system that issues a shopping assisting card that provides support in purchasing an item includes a database that stores customer information including a language used by a customer as registered information, item information including items sold at a store as registered information, store information including an item recommended by the store among the items included in the item information as registered information, and format data registered corresponding to a plurality of languages and used for producing the shopping assisting card, a data extracting unit that extracts format data corresponding to the language used by the customer and the item recommended by the store from the database, a data producing unit that produces printing data for the shopping assisting card introducing the item recommended by the store in the language used by the customer based on the format data, and a printer that prints the shopping assisting card based on the printing data.
摘要:
A wavelet inverse transform method includes a decoding object coefficient extracting step of extracting only coefficients necessary for decoding a specified area from wavelet transform coefficients, and a wavelet inverse transform step of inverse transforming coefficients extracted from the decoding object coefficient extracting step. The decoding object coefficient extracting step extracts transform coefficients not only inside the specified area but also those outside the specified area. This enables only an optional partial picture to be decoded without decoding the entire picture. A corresponding wavelet inverse transform device is also disclosed.