# 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 will default to zero (i.e. the first blob returned).

Function | Description
GetAngle(Blobs, [Index]) | Returns the angle of a blob's center of mass, relative to the center of the ROI. The center of mass of a blob represents the blob's balance point. If a sheet of a uniform material were cut out in the shape of the blob, the point upon which the blob would 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 (in pixels) of a blob. The area of a blob is calculated by counting the number of pixels contained within the blob.
GetColor(Blobs, [Index]) | Returns the color value (0.0 = black, 1.1 = white) of a blob.
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 of the blob.
GetMaxXY (Blobs, [Index]) | Returns the y-coordinate at the maximum (right-most) x-coordinate of the blob.
GetMaxY (Blobs, [Index]) | Returns the maximum (lowest) y-coordinate of the blob.
GetMaxYX (Blobs, [Index]) | Returns the x-coordinate at the maximum (lowest) y-coordinate of the blob.
GetMinX(Blobs, [Index]) | Returns the minimum (left-most) x-coordinate of the blob.
GetMinXY (Blobs, [Index]) | Returns the y-coordinate at the minimum (left-most) x-coordinate of the blob.
GetMinY (Blobs, Index) | Returns the minimum (top-most) y-coordinate of the blob.
GetMinYX (Blobs, [Index]) | Returns the x-coordinate at the minimum (top-most) y-coordinate of the blob.
GetNFound (Blobs) | Returns the number of blobs found within the specified ROI.
GetPerimeter(Blobs, [Index]) | Returns the perimeter (in pixels) of the blob. 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 will only be shown when the GetPolygon cell is selected; when set to 1, it will always be shown. The polygon will not be graphically displayed if its length exceeds approximately 4950 points.
GetScore(Blobs, [Index1], [Index2]) | Returns the Score value (0-100) of the blob.
GetSpread(Blobs, [Index]) | Returns the Spread value of the blob.
GetThresh(Blobs) | Returns either the manual binary threshold value or the optimum value (if -1, automatic specified) of the blob.
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.