OpenVX 정리

OpenVX Framework Objects

• Object: Context - The OpenVX context is the object domain for all OpenVX objects. All data objects live in the context as well as all framework objects. The OpenVX context keeps reference counts on all objects and must do garbage collection during its deconstruction to free lost references. While multiple clients may connect to the OpenVX context, all data are private in that the references that refer to data objects are given only to the creating party. The results of calling an OpenVX function on data objects created in different contexts are undefined.
• Object: Kernel - A Kernel in OpenVX is the abstract representation of a computer vision function, such as a “Sobel Gradient” or “Lucas Kanade Feature Tracking”. A vision function may implement many similar or identical features from other functions, but it is still considered a single, unique kernel as long as it is named by the same string and enumeration and conforms to the results specified by OpenVX. Kernels are similar to function signatures in this regard.
• Object: Parameter - An abstract input, output, or bidirectional data object passed to a computer vision function. This object contains the signature of that parameter's usage from the kernel description. This information includes:
  • Signature Index - The numbered index of the parameter in the signature.
  • Object Type - e.g. VX_TYPE_IMAGE, or VX_TYPE_ARRAY, or some other object type from vx_type_e.
  • Usage Model - e.g. VX_INPUT, VX_OUTPUT, or VX_BIDIRECTIONAL.
  • Presence State - e.g. VX_PARAMETER_STATE_REQUIRED, or VX_PARAMETER_STATE_OPTIONAL.
• Object: Node - A node is an instance of a kernel that will be paired with a specific set of references (the parameters). Nodes are created from and associated with a single graph only. When a vx_parameter is extracted from a Node, an additional attribute can be accessed:
  • Reference - The vx_reference assigned to this parameter index from the Node creation function (e.g., vxSobel3x3Node).
• Object: Graph - A set of nodes connected in a directed (only goes one-way) acyclic (does not loop back) fashion. A Graph may have sets of Nodes that are unconnected to other sets of Nodes within the same Graph. See Graph Formalisms.