# AVL.CreateGrayModel2

Creates a model for NCC or SAD template matching.

Namespace: AvlNet AVL.NET.dll

### Syntax

C++
C#

public static void CreateGrayModel2
(
AvlNet.Image inImage,
NullableRef<AvlNet.Region> inTemplateRegion,
AvlNet.Rectangle2D? inReferenceFrame,
int inMinPyramidLevel,
int? inMaxPyramidLevel,
float inMinAngle,
float inMaxAngle,
float inAnglePrecision,
float inMinScale,
float inMaxScale,
float inScalePrecision,
AvlNet.GrayModel2 outGrayModel,
out AvlNet.Point2D outGrayModelPoint,
IList<AvlNet.Image> diagTemplatePyramid
)


### Parameters

Name Type Range Default Description
inImageAvlNet.ImageImage from which model will be extracted.
inTemplateRegionAvlNet.NullableRef<AvlNet.Region>Region of the image from which model will be extracted. Default value: atl::NIL.
inReferenceFrameAvlNet.Rectangle2D?Exact position of the model object in the image. Default value: atl::NIL.
inMinPyramidLevelint<0, 12>0Defines the index of the lowest reduced resolution level used to speed up computations. Default value: 0.
inMaxPyramidLevelint?<0, 12>Defines the number of reduced resolution levels used to speed up computations. Default value: atl::NIL.
inMinAnglefloat0.0fStart of range of possible rotations. Default value: 0.0f.
inMaxAnglefloat0.0fEnd of range of possible rotations. Default value: 0.0f.
inAnglePrecisionfloat<0.001f, 10.0f>1.0fDefines angular resolution of the matching process. Default value: 1.0f.
inMinScalefloat<0.2f, 5.0f>1.0fStart of range of possible scales. Default value: 1.0f.
inMaxScalefloat<0.2f, 5.0f>1.0fEnd of range of possible scales. Default value: 1.0f.
inScalePrecisionfloat<0.001f, 10.0f>1.0fDefines scale resolution of the matching process. Default value: 1.0f.
outGrayModelAvlNet.GrayModel2Created model that can be used by LocateMultipleObjects_NCC and LocateMultipleObjects_SAD filters.
outGrayModelPointAvlNet.Point2DThe middle point of the created model.
diagTemplatePyramidSystem.Collections.Generic.IList<AvlNet.Image>Visualization of the model at different resolution levels.

### Description

The operation creates a Gray-based Template Matching model for the object represented in inTemplateRegion region in inImage image. The resulting model can be matched against any image using the LocateSingleObject_NCC2 or the LocateMultipleObjects_NCC2 filter.

The model consists of a pyramid of iteratively downsampled images, the original image being the first of them. The inMaxPyramidLevel parameter determines how many additional images of the pyramid shall be computed. Greater inMaxPyramidLevel values can speed up matching process considerably, but it should be set so the image on the highest pyramid level is not too distorted.

The inMinAngle and inMaxAngle parameters describe possible rotation angles of the model, i.e. only those object occurrences will be later found by LocateSingleObject_NCC2 (or LocateMultipleObjects_NCC2) whose rotation angles are in the range <inMinAngle,inMaxAngle>. The inAnglePrecision parameter controls the angular resolution of the matching process. The model is created in several rotations. The angles of consecutive rotations differ by an angle step from each other. The value of this angle step is determined on the basis of inAnglePrecision. Its value represents the multiplicity of the automatically computed angle step used as an actual step. So the greater inAnglePrecision is, the greater accuracy can be achieved and the lower is the chance of missing object occurrences. In practice however increasing inAnglePrecision above a certain threshold (unique for every object) does not increase the accuracy, only the computation time.

The inReferenceFrame is a characteristic rectangle, the position of which will be returned by LocateSingleObject_NCC2 (or LocateMultipleObjects_NCC2) as an occurrence of the object. By default, it is set to the bounding box of the inTemplateRegion.

### Remarks

Read more about Local Coordinate Systems in Machine Vision Guide: Local Coordinate Systems.

Additional information about Template Matching can be found in Machine Vision Guide: Template Matching

### Hardware Acceleration

This operation supports automatic parallelization for multicore and multiprocessor systems.

Hardware acceleration settings may be manipulated with Settings class.