Computer graphics processing and selective visual display system – Display peripheral interface input device – Light pen for fluid matrix display panel
Reexamination Certificate
1998-05-15
2001-02-13
Shankar, Vijay (Department: 2775)
Computer graphics processing and selective visual display system
Display peripheral interface input device
Light pen for fluid matrix display panel
C382S293000
Reexamination Certificate
active
06188383
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method, apparatus and computer program for image resolution conversion, and especially for converting an input image having a first resolution to an output image having a second different resolution.
2. Description of Related Art
Many kinds of matrix display devices having fixed resolutions are known, for example, a liquid crystal display (LCD) device having a resolution of “640 dots (horizontal)×480 lines (vertical)”, a plasma display device having a resolution of “800 dots (horizontal)×600 lines (vertical)”, etc. For displaying various kinds of input images having various resolutions on these matrix display devices having various resolutions, a method of performing twice-writing of pixels for scaling up the input images has been used and also a method of performing thinning out pixels for scaling down the input images has been used.
Japanese Kokai 7-104,710 (published on Apr. 21, 1995) and No. 8-137,444 (published on May 31, 1996) disclose multi-scanning display methods and apparatuses for a liquid crystal display using a technique, for example, when data of 5 pixels thin out to data of 4 pixels, the width of each pixel is magnified by 5/4, then the resulting data are averaged and outputted as output data of each pixel. These conventional methods and apparatuses have recently appeared which make it possible to cope with plural input images having different resolutions by providing plural circuits each of which converts a particular input resolution, and by selectively using one of these circuits.
Thus, the conventional resolution converting methods and apparatuses provide one dedicated resolution converting circuit for each input resolution, and switch over among the plural resolution converting circuits according to the resolution of an input image. Therefore, such methods have a disadvantage that these circuits must become large to cope with many input resolutions.
Moreover, each of the conventional resolution converting methods and apparatuses has a disadvantage in that a great number of resolution converting circuits must be individually prepared for magnifying a part of the matrix display device. In practice, it is difficult to smoothly scale up and down the input images.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method, apparatus and computer program for image resolution conversion which are capable of overcoming the above disadvantages, and particularly which are capable of converting an input image having various resolutions to an output image having various different resolutions using only a single circuit.
Another object of the present invention is to provide a method, apparatus and computer program for image resolution conversion capable of display-controlling a matrix display device having a fixed number of pixels by keeping input images of various resolutions, namely various image sizes, good in quality and capable of displaying the input images scaled up and down at multistage magnifications.
To realize the above objects, the present invention provides an image resolution converting method for converting an input image having a first resolution to an output image having a second different resolution comprising: generating a common-coordinate system common to the input image and the output image by referencing the number of pixels of the input image to the number of pixels of the output image, calculating an absolute-coordinate for each pixel of the input image and each pixel of the output image on the basis of the generated common-coordinate system, and calculating a value of a pixel of the output image from a value of a corresponding pixel of the input image with reference to the calculated absolute-coordinates of the output image.
The common-coordinate generating step generates coordinates used for handling each pixel of both the input image and the output image in the common-coordinate system, from the number of pixels of the output image and the number of pixels of the input image. For example, this process calculates a common multiple of the numbers of pixels of both images and represents pixel positions of both images by this common multiple. The absolute-coordinate calculating step obtains the coordinates of pixels of the output image by the common-coordinate system. It is thus possible to express in the absolute-coordinates how far each pixel of the output image is from its corresponding pixel of the input image, and further to obtain a ratio of a positional relation between pixels of the input image and pixels of the output image. The value calculating step obtains the value of a pixel of the output image from the absolute-coordinate of the pixel of the output image. For example, if a pixel of the output image is between two pixels of the input image, this step obtains the value of a pixel of the output image by performing a linear interpolation of the values of the two pixels of the input image based on the coordinates of these two pixels of the input image and the coordinate of the pixel of the output image. Thanks to this technique, the resolution conversion is high in quality even if both the number of pixels of the input image and the number of pixels of the output image are changing in various ways.
REFERENCES:
patent: 4829587 (1989-05-01), Glazer et al.
patent: 4870661 (1989-09-01), Yamada et al.
patent: 4949177 (1990-08-01), Bannister et al.
patent: 5068716 (1991-11-01), Takayama et al.
patent: 5068905 (1991-11-01), Hackett et al.
patent: 5179641 (1993-01-01), Comins et al.
patent: 5208871 (1993-05-01), Eschbach
patent: 5265176 (1993-11-01), Miller
patent: 5276790 (1994-01-01), Lo et al.
patent: 5452374 (1995-09-01), Cullen et al.
patent: 5754162 (1998-05-01), Cahill, III
patent: 5862268 (1999-01-01), Boehlke
patent: 2 100 092 (1982-12-01), None
patent: 7-104710 (1995-04-01), None
patent: 7-225565 (1995-08-01), None
patent: 8-137444 (1996-05-01), None
patent: 9-34411 (1997-02-01), None
patent: 10-340338 (1998-12-01), None
Frenel Vanel
NEC Corporation
Shankar Vijay
Young & Thompson
LandOfFree
Method, apparatus and computer program for image resolution... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method, apparatus and computer program for image resolution..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method, apparatus and computer program for image resolution... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2588397