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EP0694879A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Efficient methods for the evaluation of a graphical programming language

Assignee: Canon Inc
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Filing: 1995-07-24
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Granted: —
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Expires: 2015-07-24
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Abstract

Abstract A system, method and language for compositing or creating images is disclosed. The images typically comprise a plurality of graphical elements each including color and opacity information. The system utilizes operators having the graphical elements as operands in which the operators combine the operands according to a function defined by the operators, the colour information, and the opacity information, to produce new graphical elements. One part of the system includes interpreting the language by parsing and executing a sequence of statements and forming an expression tree the nodes of which comprise the graphical elements. Instructions are then derived from the tree. Another part permits the compositing of opaque graphical elements and associated clipping operations. Bounding box methods are used for locating active areas of graphical elements from the nodes. Manipulation of the expression tree is used to reduce the expected execution time of the compositing commands. An architecture is disclosed for implementing the system.

Inventors

  • 👤 George C/O Canon Information Systems Politis
  • 👤 Andrew T. R. C/O Canon Information Systems Newman
  • 👤 Timothy Merrick C/O Canon Information Syst. Long

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 15:19
CPC Classifications
G; G06; G06T; G06T11/00; G06T11/60; G06F; G06F8/00; G06F8/30; G06F8/34; G06F8/40; G06F8/41; G06F8/44; G06F8/443; G06F9/00; G06F9/06; G06F9/44; G06F9/455; G06F9/45504; G06F9/45508; G06T11/20; G06T11/26

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 102 words
A method of interpreting a program defined in a graphical programming language, said method comprising: parsing and executing a sequence of statements, said statements including the combining or rendering of graphical elements; converting said combining or rendering of graphical elements to be nodes of an expression tree wherein the descendants of said nodes are the operands of a deferred combining or rendering of graphical elements and the node is marked as having a deferred operation; and producing, from said expression tree, a series of instructions corresponding to said sequence of statements, said instructions having one operand operating on a plurality of operators.
Claim 2
Dependent Claim 28 words
A method of interpreting a program defined in a graphical programming language as claimed in claim 1, wherein the leaf nodes of said expression tree comprise graphical elements.
Claim 3
Independent Claim 37 words
A method of interpreting a program defined in a graphical programming language as claimed in claim1 or 2, wherein the internal nodes of said expression tree comprise operators for combining corresponding descendant nodes of said expression tree.
Claim 4
Independent Claim 45 words
A method of interpreting a program defined in a graphical programming language as claimed in claim1, wherein each of the internal nodes of said expression tree stores bounding box information indicative of the boundaries of the graphical elements of the children of said internal node.
Claim 5
Dependent Claim 54 words
A method of interpreting a program defined in a graphical programming language as claimed in claim 1, wherein each of the leaf nodes of said expression tree stores bounding box information indicative of the portion of the leaf nodes graphical element which appears in any final image created by said interpretation of said program.
Claim 6
Independent Claim 24 words
A method of interpreting a program defined in a graphical programming language as claimed in claim1, wherein said expression tree is a binary tree.
Claim 7
Independent Claim 28 words
A method of interpreting a program defined in a graphical programming language as claimed in claiml wherein the effect of combining or rendering said graphical elements is deferred.
Claim 8
Dependent Claim 26 words
A method of interpreting a program defined in a graphical programming language as claimed in claim 7 further comprising executing said instructions to render said image.
Claim 9
Dependent Claim 246 words
A method of interpreting a program defined in a graphical programming language as claimed in claim 7, wherein said conversion includes, for said expression tree, assigning a root node of said expression tree to be a current node, and completing the following steps (a) to (c): (a) if said current node is a leaf node then producing an instruction to load the current node's operand, otherwise (b) if the current node is only a unary operator then recursively calling steps (a) to (c) with the operand of the current node as the current node and then producing an instruction so as to implement said unary operator, otherwise (c) performing the steps of: (I) recursively calling steps (a) to (c) with a first child of the current node as the current node, (II) if a second child of the current node is a leaf node then producing an instruction utilising the operand of the second child and the current node operand, otherwise (III) performing the steps of: (1) producing an instruction to push the bounding box of the graphical element corresponding operand of the second child onto the clipping stack (2) recursively calling steps (a) to (c) with the operand of the second child as the current node, (3) producing an instruction to clear the bounding box of the operand of the second child, and (4) producing an instruction to apply the reverse of the current operator of the current node to the top of a stack.
Claim 10
Dependent Claim 25 words
A method of interpreting a program as claimed in claim 1, wherein said instructions comprise one operator or opcode and a maximum of one operand.
Claim 11
Independent Claim 22 words
A method of interpreting a program defined in a graphical programming language comprising the features of any combination of the preceding claims.

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