Facsimile and static presentation processing – Facsimile – Specific signal processing circuitry
Patent
1994-03-23
1996-08-13
Coles, Sr., Edward L.
Facsimile and static presentation processing
Facsimile
Specific signal processing circuitry
358456, 358400, 358448, 358479, 358442, 382298, 348441, H04N 140, H04N 100, H04N 132, H04N 104
Patent
active
055461948
ABSTRACT:
A video-to-FAX conversion system includes a video camera (10) for generating video signals which are then captured by a frame grabber and stored in a frame buffer (14). The data in the frame buffer is comprised of digitized values from the video signal which are stored in pixels with a first aspect ratio. A conversion device (16) is operable to map information in the frame buffer to the binary output space of a Group III FAX protocol and perform contrast enhancement thereon. The contrast enhancement includes the steps of first generating a histogram of all of the pixel values in the frame buffer (14) after expansion thereof into the output space of the Group III FAX. The histogram values are then utilized to generate an adjusted value for each of the gray scale values available for the pixels in the frame buffer 14. Each pixel in the frame buffer (14) is then expanded and the contrast enhancement applied thereto to adjust the values therein. The pixels are then processed through a dithering operation to diffuse error across the output space and then a determination is made as to whether it is a black pixel or a white pixel. This operation is done on-the-fly such that an expanded frame buffer is not required, as only a predetermined number of horizontal scan lines are required for both the contrast enhancement and image dithering operation prior to sending them to a Group III formatter (18) and, subsequently, to a Group III FAX transmitter (20) for the output of the Group III FAX.
REFERENCES:
patent: 4315285 (1982-02-01), Sommer et al.
patent: 4399470 (1983-08-01), Hibbard
patent: 4593325 (1986-06-01), Kannapell et al.
patent: 4977605 (1990-12-01), Fardeau et al.
patent: 5093871 (1992-03-01), Klein et al.
patent: 5193012 (1993-03-01), Schmidt
patent: 5235432 (1993-08-01), Creedon et al.
patent: 5359694 (1994-10-01), Concordel
Lewis, Rhys, B.Sc., Ph.D., "Practical Digital Image Processing," IBM, UK Scientific Centre, Winchester, Hants, Ellis Horwood, Limited, 1990.
Csenger, Michael, "Brooktrout Ships Fax Server for Private Nets," Communications Week, Nov. 8, 1993, p. 25.
Coles Sr. Edward L.
Howison Gregory M.
Videofaxx, Inc.
Williams Kimberly A.
LandOfFree
Method and apparatus for converting a video image format to a gr 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 and apparatus for converting a video image format to a gr, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for converting a video image format to a gr will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1052943