[−][src]Function opencv::core::subtract

pub fn subtract(
    src1: &dyn ToInputArray, 
    src2: &dyn ToInputArray, 
    dst: &mut dyn ToOutputArray, 
    mask: &dyn ToInputArray, 
    dtype: i32
) -> Result<()>

Calculates the per-element difference between two arrays or array and a scalar.

The function subtract calculates:

  • Difference between two arrays, when both input arrays have the same size and the same number of channels: block formula
  • Difference between an array and a scalar, when src2 is constructed from Scalar or has the same number of elements as src1.channels(): block formula
  • Difference between a scalar and an array, when src1 is constructed from Scalar or has the same number of elements as src2.channels(): block formula
  • The reverse difference between a scalar and an array in the case of SubRS: block formula where I is a multi-dimensional index of array elements. In case of multi-channel arrays, each channel is processed independently.

The first function in the list above can be replaced with matrix expressions:

ⓘThis example is not tested
dst = src1 - src2;
dst -= src1; // equivalent to subtract(dst, src1, dst);

The input arrays and the output array can all have the same or different depths. For example, you can subtract to 8-bit unsigned arrays and store the difference in a 16-bit signed array. Depth of the output array is determined by dtype parameter. In the second and third cases above, as well as in the first case, when src1.depth() == src2.depth(), dtype can be set to the default -1. In this case the output array will have the same depth as the input array, be it src1, src2 or both.

Note: Saturation is not applied when the output array has the depth CV_32S. You may even get result of an incorrect sign in the case of overflow.

Parameters

  • src1: first input array or a scalar.
  • src2: second input array or a scalar.
  • dst: output array of the same size and the same number of channels as the input array.
  • mask: optional operation mask; this is an 8-bit single channel array that specifies elements of the output array to be changed.
  • dtype: optional depth of the output array

See also

add, addWeighted, scaleAdd, Mat::convertTo

C++ default parameters

  • mask: noArray()
  • dtype: -1