摘要:
An image data coding method for a case where image data are transmitted or filed upon being binary coded includes steps of replacing a predetermined pixel by a predicted value predicted by a plurality of pixels peripheral to the predetermined pixel, in conformance with a coded image data compression technique, and performing binary coding while dispersing an error, which is generated by the replacement, among peripheral pixels. Also provided are a variety of image data coding apparatus for practicing this image data coding method. The invention makes it possible to perform binary coding and compression of half-tone image data very efficiently.
摘要:
An image processing apparatus such as a digital printer or digital facsimile apparatus for half tone processing input image data has: an input device to input image data indicative of a concentration of an image; a discriminating circuit to discriminate whether the input image data is smaller than a threshold value or not; a binarizing circuit to binarize the input image data into binary data of high and low levels; and a setting circuit to set the binary output of the image data to the low (0) level irrespective of the result of the binarization by the binarizing circuit when the input image data is determined to be smaller than the threshold value. The input device includes a reading circuit to read the original image and a generator to generate image data indicative of the original image concentration. When the pixel concentration to be processed by an error diffusion method is smaller than the threshold value, the error data generated for that pixel is set to 0, with the result that particles-like noises in the high contrast portion are eliminated and the encoding efficiency in highlight portions is improved. Thus, a high quality image of excellent resolution and gradations can be transmitted at a high speed.
摘要:
An image processing apparatus for digitizing an analog image by dispersing the digitizing error to the surrounding areas. The characteristics or edge of the analog image are identified, and the error dispersing area is varied according to the result of identification, thus enabling reproduction of the image with high quality regardless of the nature of the original image.
摘要:
An image treatment apparatus comprising: an input device for inputting image data; a setting circuit serving as a reference when the image data is quantized in accordance with the image data input by the input device; a quantizing circuit for quantizing the image data; and a device for outputting an image in accordance with the result of treatment performed by the quantizing circuit, wherein the quantizing circuit performs the quantization by correcting the error between the image data input by the input device and the image output by the outputting device.
摘要:
There is provided an image processing apparatus which handles an image as a digital signal, comprising: an input device to input image data indicative of a concentration of an image; a binarization circuit to binarize the input image data; a positive/negative state detection circuit to detect whether error data generated when the image data is binarized by the binarization circuit is in a positive state or a negative state; and a selector to select whether the error data generated upon binarization is to be corrected or not, on the basis of the positive or negative state of the error data. The input device has a generator to read an original and generate an analog image signal and a converter to convert the analog image signal into the digital image data. The error data is the difference between the input image data and the binary data produced by the binarization circuit. With this apparatus, an image of a good picture quality can be obtained by improving the error diffusion method as a halftone processing method. Even when portions of high and low concentrations in an original are very close to each other, the blanking phenomenon, wherein no dot is printed in the low concentration area near the boundary between those portions, and the consequent problem that the reproduced image lacks its proper content can be prevented.
摘要:
An image processing apparatus for digitizing an analog image by dispersing the digitizing error to the surrounding areas. The characteristics or edge of the analog imnage are identified, and the error dispersing area is varied according to the result of identification, thus enabling reproduction of the image with high quality regardless of the nature of the original image.
摘要:
There are provided an image processing method and apparatus for processing an image by digital signals and for reproducing the image with a high picture quality. The apparatus comprises: an input device to input a plurality of color image data; a first processor to perform a dotting process on the color image data input by the input device; and a second processor to digitize the color image data dot-processed by the first processor, wherein the first processor changes the dotting process for each of the color image data. With the apparatus, first and second features of the input image are detected and different dotting processes are executed in accordance with the first and second features, so that the image process can be executed at a high speed and a color image having excellent gradations and resolution can be obtained while suppressing the occurrence of a color moire.
摘要:
A half-tone image is produced by scanning a plurality of input points of an original, outputting a screened image having a plurality of black and white dots and transmitting signals representing the screened image to a marking device. The size of each plurality of dots is determined from a recursive relationship between a value of a current input point, a previous output and an error representing a difference between a value of a previous input point and the previous output.
摘要:
There is provided an improvement on the error dispersion method for binary digitizing of an image, in which an area of plural pixels is digitzed, and the error into the digitizing is dispersed in a neighboring area of plural pixels. In the latter area the digitization is conducted according to the image data of plural pixels and the error data dispersed into this area.
摘要:
There is an image processing apparatus for digitally processing an image. This apparatus comprises: a binarization circuit to binarize image data by a predetermined threshold value; a processor to correct errors generated in binarization; a first detector to detect an edge direction of the image from the image data; and a second detector to detect an edge quantum of the image from the image data. The process corrects the error data in accordance with the edge direction detected by the first detector or the edge quantum detected by the second detector. The errors to be corrected by the processor are the errors between the output concentration data after the binarization and the image concentration data. The processor adds weight coefficients to the error data in a predetermined range stored in a memory and then adds the weighted error data to image data to be newly binarized. The sum of the weight coefficients which are used in the weighting process is set to "1". With this apparatus, a high quality apparatus can be reproduced with a high fidelity from an original including many edges.