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008200923s1979    onca    o    f000 0 eng d
040 |aCaOODSP|beng|erda|cCaOODSP
043 |an-cn---
0861 |aCo24-3/8-699-1979E-PDF
1001 |aBown, H. G., |eauthor.
24510|aPicture description instructions, PDI, for the Telidon videotex system / |cby H.G. Bown, C.D. O'Brien, W. Sawchuk and J.R. Storey.
264 1|aOttawa : |bCommunications Research Centre, |c1979.
300 |a1 online resource (iii, 71 pages) : |billustrations.
336 |atext|btxt|2rdacontent
337 |acomputer|bc|2rdamedia
338 |aonline resource|bcr|2rdacarrier
4901 |aCRC technical note ; |vno. 699-E
500 |aIssued also in French under title: Instructions de description de l'image, IDI, pour le système vidéotex Télidon.
500 |a"Technology and Systems Branch."
500 |a"November 1979."
500 |aDigitized edition from print [produced by Innovation, Science and Economic Development Canada].
500 |aSome pages rotated in this copy.
5203 |a"The Telidon Videotex system is a method by which information can be accessed from central data bases by the general public. By the use of a domestic home television receiver augmented by a micro-computer controlled interface device a user can access pages of graphical and textual information over a public common carrier communications facility such as the telephone network, a cable television line or the data may be even encoded into unused space in a broadcast television signal. In order to transmit information to a Telidon terminal, at minimum bandwidth, and in a manner independent of the type of communications channel, a coding scheme was devised which encodes a picture into the geometric drawing elements which compose it. These "Picture Description Instructions" are an alpha-geometric coding model and are based on the primitives of POINT, LINE, ARC, RECTANGLE, POLYGON, point by point BIT encoded images and TEXT encoded as ASCII characters. This document provides a detailed specification of this code as well as a description of the principles which make it independent of communications channel and display hardware"--Abstract, page 1.
530 |aIssued also in print format.
650 5|aTelidon (Data transmission system)
650 0|aVideotex systems|zCanada.
650 0|aImage transmission.
7102 |aCommunications Research Centre (Canada), |eissuing body.
77508|tInstructions de description de l'image, IDI, pour le système vidéotex Télidon / |w(CaOODSP)9.891737
830#0|aCRC technical note ;|vno. 699-E.|w(CaOODSP)9.882494
85640|qPDF|s1.69 MB|uhttps://publications.gc.ca/collections/collection_2020/isde-ised/Co24/Co24-3-8-699-1979-eng.pdf