Scalar
multiplication
In this operation a scalar is multiplied with every pixel in a raster band. The raster band is overwritten with the result of the addition.
The operation is provided in a high-level and a low-level format. In the high-level format a raster object, a band identifier and a token are specified, together with the scalar. The operation applies to all pixels and the result is stored in the specified band. In the low-level format the operation is applied to a block of contiguous memory containing a specified number of pixels. The low-level format is useful to chain a number of operations without the overhead of storing intermediate results.
If you want to preserve the original raster band, you should make a copy of the band first.
High-level declaration:
procedure DSpGMMultiplyScalar(const r: TDSpRaster; const band, token: integer;
scalar: TDSpFloat64);
Low-level declarations:
procedure DSpGMMultiplyScalarUInt32
procedure DSpGMMultiplyScalarInt32
procedure DSpGMMultiplyScalarInt64
procedure DSpGMMultiplyScalarFloat32
procedure DSpGMMultiplyScalarFloat64
(const data: pointer; pixels: integer;
fill, scalar: TDSpFloat64);
| Parameter | Description |
| r | A valid raster object. It must be opened for write access. |
| band | The identifier of the raster band. The band must exist in the raster, and it can be of any type. The data type can be any 32-bit or 64-bit data type. |
| token | The access token for the raster. The token has to be generated for write access. |
| scalar |
The value that every pixel of the raster band is multiplied with. This value will be converted to the data type of the raster band before the operation. |
| data | A pointer to a block of memory containing pixels pixel values. |
| pixels | Number of pixels in the data block of memory. |
| fill | The missing data value of the raster band. |