Abstract: This invention relates to an image encoding method and apparatus, and particularly has as its object to satisfactorily control the amount of encoded image data. In order to achieve this object, according to this invention, there is disclosed a technique for sequentially controlling the code amounts in accordance with accumulated code amount information and accumulated encoded area information, so that variable-length codes of an image fall within a predetermined memory capacity in a single pass. More specifically, in an image processing apparatus having a compression processor (15) for compressing input image information, and a memory (16) for storing encoded data by the compression processor (15), a code amount controller (14) calculates a reference code amount on the basis of the input image information, and controls the encoding condition of the compression processor (15) on the basis of the calculated reference code amount.

Abstract: This invention is to provide encoding and decoding apparatuses capable of increasing the processing speed even when a learning RAM need be frequently cleared for encoding or decoding in units of bands, and an image processing apparatus using the same. The encoding or decoding apparatus includes a plurality of learning RAMs (502, 602) for storing learned contents, and switches (521, 523, 525, 621, 623, 725, 630) for setting one of the plurality of learning RAMs in a learning state and the other in the initialized state and switching the state for every band processing.

Abstract: This invention has as its object to suppress an increase in circuit scale and to simplify a circuit structure by executing a filter process using a plurality of arithmetic units each of which makes multiplication and addition.

Abstract: A decoding device for Huffman codes, provided with an operation circuit for determining, from a Huffman code to be decode, the code length of the Huffman code and a predetermined code number thereof by calculation, and a conversion circuit for converting the code number into a fixed-length code prior to encoding.

Abstract: In an image processing method, image information described by a page descriptor language is developed by the page descriptor language into a form not pasted with to-be-pasted image information, without reading out, for image development, the to-be-pasted image information from a unit for storing the to-be-pasted image information. The image information in the form not pasted with the to-be-pasted image information and the to-be-pasted image information are separately transmitted to a printer. The image information in the form not pasted with the to-be-pasted image information is compressed by reversible coding. The to-be-pasted information is compressed by irreversible coding.

Abstract: A code concatenating unit incorporates carry signals in a retained remaining code, and couples thereto an inputted variable length code to generate a concatenated code. An undefined code length detection unit, and first to third computation units acquire the code length of a defined code portion that is not influenced by the carry signal and output the same. As long as the whole of the concatenated code is an undefined code, a cumulative addition/subtraction unit adds cumulatively its code length, and a code generation unit generates and outputs a predetermined defined code with the cumulative value as its code length.

Abstract: In an image processing method, image information described by a page descriptor language is developed by the page descriptor language into a form not pasted with to-be-pasted image information, without reading out, for image development, the to-be-pasted image information from a unit for storing the to-be-pasted image information. The image information in the form not pasted with the to-be-pasted image information and the to-be-pasted image information are separately transmitted to a printer. The image information in the form not pasted with the to-be-pasted image information is compressed by reversible coding. The to-be-pasted information is compressed by irreversible coding.

Abstract: Analyzer 121 estimates time for rendering image data based on the number, the types etc. of rendering commands, stored in intermediate memory 113, and determines whether or not there is a possibility of overrun. If there is the possibility of overrun, image data of respective bands formed in band buffer 118 are sequentially compressed and stored into compressed image memory 115. When the image data for one page has been stored, the data in the compressed image memory 115 is sequentially expanded and supplied to printer engine 130. This avoids failure of image output due to overrun while reducing the capacity of the image memory.

Abstract: Disclosed are an image processing method and apparatus whereby the capability of coding/decoding processing accompanied by learning is improved, this also making it possible to achieve high-speed image formation processing without error. The apparatus includes a coder for generating coded data by arithmetically coding image data, a counter for counting the number of times learning is performed by the coder, and a comparator which, when a count recorded by the counter attains a value stored in a register, stops the learning operation executed by the coder.

Abstract: A video memory device is provided with a memory circuit, a write control circuit for controlling writing to the memory circuit by utilizing the horizontal synchronizing signal of a video signal input to the memory circuit, and a read control circuit for controlling reading from the memory circuit by utilizing the horizontal synchronizing of a video signal output from the memory circuit.

Abstract: Decompression of Huffman encoded data is obtained by calculating, from a sequence of bits which includes a Huffman code to be decoded, a code length and a code number of the Huffman code to be decoded. The code number is determined based on the rank of the Huffman code when compared to plural other reference Huffman codes with respect to relative probabilities of occurrence. A conversion of the code number into a fixed-length decoded code corresponding to a code which has been encoded is also provided. Corresponding compression of data is obtained by converting a fixed-length code to be encoded into a code number, the code number being determined based on the rank of the Huffman code when compared to plural other reference Huffman codes with respect to relative probabilities of occurrence. By calculation from the code number, a Huffman code to be output and a code length of the Huffman code are then generated.

Abstract: An image encoding apparatus of this invention extracts a character/line image from a multi-value image, and substitutes image information corresponding to the extracted character/line image with substitution data based on the image information. Thereafter, the apparatus encodes the image information corresponding to the character/line image, and the remaining image information by different methods, thereby performing efficient image encoding while preserving quality of a character/line image in a multi-value image.

Abstract: An unpacking circuit 103 takes the top 16-bit data from an input code after eliminating previously decoded data on the basis of code length information 106. An operation unit 501 obtains a redundant code number of a Huffman code inputted from the unpacking circuit 103 and upper three bits of the code length information 106. By referring to a decoding table 503, an eight-bit fixed-length data and the least significant bit of the code length information are obtained correspondence with an input nine-bit redundant code number signal 502. Therefore, memory size required for storing the decoding table 503 is 2.sup.9 .times.9 bits=576 bytes, thus, comparing to a case where memory size for storing the decoding table of 96 kbytes when changing into a fixed code length by using only the decoding table, it is possible to use a decoding table of smaller size.

Abstract: An image interpolating circuit for producing pixel information of an interpolation line located between first and second scanning lines by using pixel information of the first and second scanning lines. A detecting circuit is provided for detecting an oblique edge pattern by using the pixel information of the first and second scanning lines, and an interpolation signal producing circuit is provided for setting the number of pixels of the interpolation scanning line to be larger than the number of pixels of the first and second scanning lines and for producing the pixel information for the interpolation line in accordance with a detection output of the detecting circuit.

Abstract: An information signal recording system arranged to divide original information signals into signal groups, each bearing a predetermined amount of information, to have a plurality of compressing modes for different information compressing ratios and to compress the information signals of each group in one of the different compressing ratios in recording these signals on a tape-shaped magnetic recording medium comprises first compressed information signal forming means which operates on all these groups to form and produce a first compressed information signal consisting of only the information signals of a specific part of each of these groups; second compressed information signal forming means which operates on some of these groups to form and produce a second compressed information signal consisting of information signals of each groups excluding the information signals of the specific part; a magnetic head which records signals on the tape-shaped magnetic recording medium by tracing the medium in a directio

Abstract: In an image signal recording system for recording on a recording medium an original image signal corresponding to an original picture which is comprised of a plurality of pixels, the original picture is divided into a plurality of pixel blocks each consisting of a predetermined number of pixels, and image signals each corresponding to the associated pixel block divided are recorded on the recording medium in accordance with a first recording mode and a second recording mode which are mutually different in a recording format. Either of the first and second recording modes is selected on each of the plurality of pixel blocks and a recording mode information signal corresponding to the selected recording mode is generated. There are recorded on the recording medium, the first image information signal or the second image information signal formed and the recording mode information signal generated, on a multiple basis.

Abstract: An address exchanger and a data exchanger are provided at both sides of a plurality of look-up tables (LUTs). An even number address is constantly accessed at one of the LUTs and an odd number address is constantly accessed in the other LUTs. An interpolating operation on the basis of values output from the respective LUTs may constantly cause the same results as can be obtained without address exchange. By this, for the memory to be accessed by the odd number address and the even number address, a grid point data for other transformation characteristics may be stored. Therefore, in the data transformation apparatus performing data transformation through interpolation employing a plurality of LUTs, memories of respective LUTs can be efficiently used for permitting data transformation of a plurality of kinds of transformation characteristics.

Abstract: Binary data are obtained on data of reference pixels included in the upper and below lines of an interpolated pixel through binarizing circuits by comparing with the threshold value determined based on the reference pixel data. Binary interpolation data of the interpolated pixel are obtained from the plurality of binary data. Maximum threshold data is determined as multivalued interpolation data of the interpolated pixel, when the binary interpolation data is "1".

Abstract: An information signal recording system arranged to divide original information signals into signal groups, each bearing a predetermined amount of information, to have a plurality of compressing modes for different information compressing ratios and to compress the information signals of each group in one of the different compressing ratios in recording these signals on a tape-shaped magnetic recording medium comprises first compressed information signal forming assembly which operates on all these groups to form and produce a first compressed information signal consisting of only the information signals of a specific part of each of these groups; second compressed information signal forming assembly which operates on some of these groups to form and produce a second compressed information signal consisting of information signals of each groups excluding the information signals of the specific part; a magnetic head which records signals on the tape-shaped magnetic recording medium by tracing the medium in a di

Abstract: An image processing apparatus and method capable of suppressing noise and improving the S/N ratio of a processing output signal when a color signal representing color image data is processed. The RGB.fwdarw.YUV converter is comprised of conversion units 201-1 . . . 201-k, adder 205, and rounding processing circuit 206 which are built in the image processing apparatus such as a color printer, each of the conversion units 10 201-1 . . . 201-k is provided with an adder 11 between the multiplier 10 and rounding processing unit 12 and corrects errors generated by the rounding processing circuit 206.