摘要:
An image transforming section subjects image data to compression processing. A quantizing section quantizes the transformed data using a quantization width. A variable-length coding section subjects the quantized data to variable-length coding. A code-amount computing section determines a total code amount by accumulating partial code amounts. A control section performs control based on the code amount. An estimating method selecting section adaptively selects a quantization width estimating method. A coded result storage section stores data of a code amount corresponding to the quantization width. First and second quantization width estimating sections have different quantization width estimating methods.
摘要:
An image quality control apparatus having an image divider, a converter, an image analyzer, an image output property circuit, a quantization method selector, a quantizer and a coder. The image divider divides an input image into a plurality of divided images including a predetermined number of picture elements. The converter converts the divided images into converted coefficients. Then, the image analyzer determines a property of the divided images which is output by the image output property output circuit. A quantization selector selects a quantization method in response to the divided image property that was found by the image analyzer and the image output property output circuit. The quantizer quantizes the conversion coefficients found by the converter in accordance with the quantization methods selected by the quantization selector. A coder then codes the conversion coefficients quantized by the quantizer.
摘要:
A plurality of reference pixel extracting means check their corresponding reference pixel ranges and pixel values in predetermined auxiliary regions. Reference pixel range selecting means selects a reference pixel range based on the checked pixel values. When the number of types of pixel values for an input image is found to be locally low in the selected reference pixel range, the number of reference pixels is increased. On the other hand, when the number of types of the pixel values for the input image is found to be locally large, the number of reference pixels is decreased. As a result, states can be generated by a Markov model image encoding system capable of improving encoding efficiency without increasing the number of the states sharply. Owing to the above construction, even when the number of tones for the input image is high upon Markov model image encoding, the number of reference pixels can be increased without abruptly increasing the number of states later on to improve compression efficiency.
摘要:
An image information coding apparatus includes a block generator for dividing image information into pixel blocks, each of which consists of a predetermined number of pixels. A block selector selects a pixel block in a position different from that of a pixel block selected in a preceding block line in a main scanning direction from the pixel blocks generated by the block generator. A parameter setting device sets a coding parameter to a predetermined value. A first variable-length coding device conducts variable-length coding of the pixel block selected by the block selector using the coding parameter. A code amount controller changes a value of the coding parameter so that the code amount of the pixel block selected by the block selector and coded by the first variable-length coding device is not more than a predetermined code amount, and a second variable-length coding device conducts variable-length coding of all of the pixel blocks using a coding parameter changed by the code amount controller.
摘要:
The memory capacity required for temporarily holding image data with respect to a printer is reduced, and loads involved in supplying image data, such as decoding and conversion processes, are dispersed and reduced. The apparatus divides image data in parallel with a main scanning direction by an image divider, stores the divided data in image data memory, and supplies the divided image data to image data temporary memory by an image data supply to perform a decoding process. In order to provide a matching with a process speed, the image data temporary memory temporarily retains the divided image data, and a printer prints an image on a sheet of paper on the basis of the divided image data stored in the image data temporary memory. A predictor predicts a supply process time by way of image data supply, and an image data supply control causes the image data supply to start the supply process of the divided image data at a time preceding the time for the start of the print process by the printer according to the time predicted.
摘要:
An image analysis device and method that have a mechanism for exactly predicting image quality determining factors and determine a coding parameter for an input image by combining plural different image quality determining factors, which does not deteriorate the image quality of the input image and raises the compression ratio as high as possible. In the image analysis device, an image extraction unit 102 extracts an image area to be analyzed from an input image 101. The extracted image area 102 is input to plural physical quantity calculating units 104. Each physical quantity calculating unit 104 calculates a physical quantity 105 independently of others and each of obtained physical quantities 105 is input to plural image quality determining factor calculating units 106. On receiving the plural physical quantities 105, each of the image quality determining factor calculating units 106 calculates an image quality determining factor 107. A coding parameter calculating unit 108 calculates a coding parameter based on the plural image quality determining factors 107 output from the plural image quality determining factor calculating units 106.
摘要:
Transfer control information for controlling a transfer amount per unit time of a transfer path is delivered from a transfer control section to an information transfer section. During encoding, the information transfer section receives image information from an external device in accordance with the transfer control information, and inputs the same to an image-information encoding/decoding section. A code-amount control section forwards code-amount control information for controlling the code amount to the image-information encoding/decoding section. The image-information encoding/decoding section encodes the image information in accordance with the code-amount control information outputted from the code-amount control section. The information transfer section transfers to an external device encoded information outputted from the image-information encoding/decoding section, while the transfer amount per unit time is being controlled by the transfer control section.
摘要:
In an image forming apparatus, memory capacity necessary for temporarily retaining image data is reduced. A decoding process is carried out by diving image data for one frame into element data for each color component Y, M, C and K. The element data for each color component is stored in the temporary memory. A controller starts conveyance of recording media on the basis of estimation of the completion time of decoding processing by a decoding speed estimator, and controls the recorders for Y, M, C and K to execute the recording process of element data retained in the temporary memory. This results in an image being recorded on the recording medium for each element data retained in the temporary memory, such that the conveyance of the recording media and the supply of data to the recorders for Y, M, C and K are matched, and the data amount to be retained in the temporary memory is reduced.
摘要:
An image signal analyzing system for analyzing a pattern of an image on the basis of the waveforms of the image signals. The system includes a block extracting section for sampling an image signal and dividing the sampled image signal into input pixel blocks each consisting of m.times.n pixels (m and n are positive integers), a mean value separating section for subtracting a mean value from each pixel in the pixel block, a first analyzing section for analyzing a feature quantity of the direction of the tone variation of a mean-value separated block obtained from the mean value separating section, a second analyzing section for analyzing a feature quantity of the direction of amplitude of the mean-value separated block, and a judging section for judging a feature of waveform of the input pixel block on the basis of the analysis results of the first analyzing section and the second analyzing section.
摘要:
An image signal encoding device which includes a code transforming unit. The code transforming unit includes a separation unit which separates mode information from first code data, a locally decoding unit which locally decodes the first code data using a decoding operation corresponding to the mode information and outputs locally decoded pixel block, and a second encoding unit which encodes the locally decoded pixel block using an encoding operation corresponding to the mode information and outputs second code data. According to the image signal encoding device, the first code data is re-encoded into the second code data having a higher compressibility so as to perform efficient data transmission and storage.