# Blobs Vision Data Access functions

This topic lists the available Vision Data Access functions that get values from Blob functions.

Note: Each of the following functions references a Blobs data structure for the first parameter. Index (zero-based) determines which blob is being indexed from the structure. If the index is not specified, the index defaults to zero (that is, the first blob returned).

Function | Description
GetAngle(Blobs, [Index]) | Returns the angle of the center of mass of a blob, relative to the center of the ROI. The center of mass of a blob represents the balance point of a blob. If a sheet of a uniform material were cut out in the shape of the blob, the point upon which the blob could balance is the center of mass. Note that the center of mass of a blob might not actually lie within the blob itself.
GetArea(Blobs, [Index]) | Returns the area of a blob in pixels. The area of a blob is calculated by counting the number of pixels contained within the blob.
GetColor(Blobs, [Index]) | Returns the color value of a blob. 0.0 is black, 1.1 is white.
GetElongation(Blobs, Index) | Returns an elongation value from the specified blob.
GetHeight(Blobs, [Index]) | Returns the height of the indexed blob.
GetHoles(Blobs, [Index]) | Returns the number of holes contained within the blob.
GetMaxX (Blobs, [Index]) | Returns the maximum right-most X-coordinate value of the blob.
GetMaxXY (Blobs, [Index]) | Returns the Y-coordinate value at the maximum right-most X-coordinate value of the blob.
GetMaxY (Blobs, [Index]) | Returns the maximum lowest Y-coordinate value of the blob.
GetMaxYX (Blobs, [Index]) | Returns the X-coordinate value at the maximum lowest Y-coordinate value of the blob.
GetMinX(Blobs, [Index]) | Returns the minimum left-most X-coordinate value of the blob.
GetMinXY (Blobs, [Index]) | Returns the Y-coordinate value at the minimum left-most X-coordinate value of the blob.
GetMinY (Blobs, Index) | Returns the minimum top-most Y-coordinate value of the blob.
GetMinYX (Blobs, [Index]) | Returns the X-coordinate value at the minimum top-most Y-coordinate value of the blob.
GetNFound (Blobs) | Returns the number of blobs found within the specified ROI.
GetPerimeter(Blobs, [Index]) | Returns the perimeter of the blob in pixels. The perimeter of the blob is calculated by counting the number of external pixel edges, for every pixel contained in the blob.
GetPolygon(Blobs, Index, [Show]) | Returns a Polygon data structure, which represents the boundary points of the specified blob. The Polygon data structure can be used as an input for functions that have an External Region parameter, which allows for image processing to be performed within the boundary of a blob. Note: Optionally, the Show parameter can be specified. When set to 0 (the default), the polygon graphic is only shown when the GetPolygon cell is selected; when set to 1, it is always shown. The polygon is not graphically displayed if its length exceeds approximately 4950 points.
GetScore(Blobs, [Index1], [Index2]) | Returns the Score value of the blob between 0-100.
GetSpread(Blobs, [Index]) | Returns the Spread value of the blob.
GetThresh(Blobs) | Returns either the manual binary threshold value or the optimum value of the blob. If the value is -1, the function is set to automatic.
GetWidth(Blobs, [Index]) | Returns the width of the indexed blob.
GetX(Blobs, [Index1], [Index2]) | Returns the X-coordinate.
GetY(Blobs, [Index1], [Index2]) | Returns the Y-coordinate.