Method

VipsImagesubtract

Declaration [src] 

int
vips_subtract (
  VipsImage* in1,
  VipsImage* in2,
  VipsImage** out,
  ...
)

Description [src]

This operation calculates in1 - in2 and writes the result to out.

If the images differ in size, the smaller image is enlarged to match the larger by adding zero pixels along the bottom and right.

If the number of bands differs, one of the images must have one band. In this case, an n-band image is formed from the one-band image by joining n copies of the one-band image together, and then the two n-band images are operated upon.

The two input images are cast up to the smallest common format (see table Smallest common format in arithmetic), then the following table is used to determine the output type:

VipsSubtract type promotion input type output type uchar short char short ushort int short int uint int int int float float double double complex complex double complex double complex

In other words, the output type is just large enough to hold the whole range of possible values.

See also

vips_add(), vips_linear().

This method is not directly available to language bindings.

Parameters

in2

Type: VipsImage

Input image.

The data is owned by the caller of the method.
out

Type: VipsImage

Output image.

The argument will be set by the function.
The caller of the method takes ownership of the returned data, and is responsible for freeing it.
...

Type: 

NULL-terminated list of optional named arguments.

Return value

Type: int

0 on success, -1 on error.