Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
230 words
I. An image processing apparatus having first processing means (20) for receiving an electrical binary signal representing a continuous-tone input image, which is converted by a dither method using a first dither matrix (M) with a matrix pattern of multi-level threshold values and with a matrix size, and for converting a pixel-density of said binary image signal at a conversion ratio, to produce a signal representing a converted image with the pixel coordinates as defined by said conversion ratio, characterized in that said first processing means (20) comprises: second processing means (22) for calculating coordinates positions of pixels of said converted image in said binary image, for comparing the pixels of said binary image with pixels of said converted image, and for selecting a certain pixel from among the pixels of said binary image which defines a fiducial point (Of); third processing means (24) for defining a window area (W) on said binary image, which contains said certain pixel (Of) and corresponds to said matrix size of said first dither matrix (M), and for extracting pixels of said binary image which are contained in said window area (W) and located around said certain pixel, as reference pixels; and fourth processing means (26) for calculating an average density of said reference pixels (p) and for generating image-density data locally averaged, said image-density data being binarized by using a second dither matrix.
Claim 2
Dependent Claim
52 words
The image processing apparatus according to claim I, characterized in that said second processing means (22) detects a pixel of the binary image that is located closest to a pixel of said converted image, from among the pixels of said binary image, and for specifying the detected pixel as said certain pixel.
Claim 3
Dependent Claim
24 words
The image processing apparatus according to claim 2, characterized in that said second dither matrix is substantially the same as said first dither matrix.
Claim 4
Dependent Claim
29 words
The image processing apparatus according to claim 3, characterized by further comprising memory means (18) connected to said first processing means (14), for storing said binary image signal (16).
Claim 5
Dependent Claim
218 words
An image processing method wherein an electrical signal (12) representing a continuous-tone input image is converted into a binary image signal (16) by a dither method using a first dither matrix - (M) with a matrix pattern of multi-level threshold values and with a matrix size, and the binary image signal (16) is subjected to a pixel-density conversion process at a conversion ratio, to generate a signal representing a converted image with the pixel coordinates as defined by said conversion ratio, characterized in that said method comprises the steps of: calculating coordinates positions of pixel of said converted image in said binary image; comparing the pixels of said binary image with pixels of said converted image to select a certain pixel (Of) from among the pixels of said binary image, said certain pixel defining a fiducial point; defining a window area (W) on said binary image, which contains said certain pixel and corresponds in size to said matrix size of said first dither matrix (M); extracting pixels of said binary image which are contained in said window area (W) and located around said certain pixel (Of), as reference pixels - (p); and calculating an average density of said reference pixels (p), to generate image-density data locally averaged, said image-density data being binarized by using a second dither matrix.
Claim 6
Dependent Claim
48 words
The image processing method according to claim 5, characterized in that a pixel of said binary image that is located closest to a pixel of said converted image is detected from among the pixels of said binary image, and the detected pixel is specified as said certain pixel.
Claim 7
Dependent Claim
24 words
The image processing apparatus according to claim 6, characterized in that said second dither matrix is substantially the same as said first dither matrix.