Showing papers on "Bilateral filter published in 1988"

Apparatus for reducing artifacts in error diffused images

Abstract: A recursive spatial filter interchanges the value of a control pixel with that of the value of a predetermined one of the surrounding pixels in a pixel mask when a specific image pattern occurs in the digital image The use of such a filter eliminates certain highly visible grain patterns from the halftoned digital image while preserving the average gray level

Image forming method using secondary electrons from object for noise elimination

Abstract: An image forming method includes a first step of irradiating a beam onto an object, and using an intensity corresponding to an image area onto which the beam was irradiated as an intensity of a pixel at the center of the image area, and scanning a beam throughout the inspection area of the object to obtain an image within the inspection area as a collection of pixels arranged at intervals smaller than a beam diameter; and a second step of assigning a pixel to be processed and neighboring pixels with coefficients in accordance with a beam intensity distribution, multiplying the intensity of each pixel by each assigned coefficient, determining a new intensity of the pixel to be processed in accordance with the sum of respective products, and repeating the new intensity determining process for all pixels necessary to be processed. In the second step, the value of the coefficients for those pixels except on the scanning direction may be reduced. Further, a third step may be provided for linearly-transforming the intensities so as to make the intensities of respective pixels to be distributed within a predetermined range.

Method of and apparatus for recording image in the form of pixel array

Abstract: In an image recording system the size of recording pixels (7) is not necessarily an integer multiple of the size of original pixel (2). A plurality of original images are combined to produce a recorded image based on the combination of the original pixels. In the process, the spatial relationship between the respective pixel arrangements of an original pixel array and a recording pixel array is detected. Based on that spatial relationship, a plurality of original pixels which surround each recorded pixel are specified and the pixel image data for the specified original pixels are interpolated to obtain each datum in the recorded pixels. This interpolation process is carried out for all recording pixels except for those recording pixels in which there is detected to occur a combination boundary of the original images.

Image contour detecting apparatus

Abstract: An apparatus for detecting one or more contours of an image formed on a screen. The apparatus comprises a scanner for raster scanning pixels located on scan lines extending in paralllel with each other in the X direction of a two-dimensional coordinate system to successively produce binary pixel data regarding the scanned pixels. The binary pixel data have a first value representing a background forming pixel or a second value representing an object forming pixel. The binary pixel data are transferred to a pixel data matrix stored therein. The pixel data matrix includes pixel data regarding two adjacent pixels located on the next scan line. The latter two adjacent pixels are respectively adjacent to the former two adjacent pixels in the Y direction of the two-dimentional coordinate system. The apparatus also comprises a processing circuit which receives the pixel data matrix transferred thereto from the pixel data matrix forming circuit for producing data indicating the image contour(s).

Image forming method using secondary electrons from object

Abstract: An image forming method includes a first step of irradiating a beam onto an object, and using an intensity corresponding to an image area onto which the beam was irradiated as an intensity of a pixel at the center of the image area, and scanning a beam throughout the inspection area of the object to obtain an image within the inspection area as a collection of pixels arranged at intervals smaller than a beam diameter; and a second step of assigning a pixel to be processed and neighbouring pixels with coefficients in accordance with a beam intensity distribution, multiplying the intensity of each pixel by each assigned coefficient, determining a new intensity of the pixel to be processed in accordance with the sum of respective products, and repeating the new intensity determining process for all pixels necessary to be processed. In the second step, the value of the coefficients for those pixels except on the scanning direction may be reduced. Further, a third step may be provided for linearly-transforming the intensities so as to make the intensities of respective pixels to be distributed within a predetermined range.