Method

VipsImagecountlines

Declaration [src]

int
vips_countlines (
  VipsImage* in,
  double* nolines,
  VipsDirection direction,
  ...
)

Description [src]

Function which calculates the number of transitions between black and white for the horizontal or the vertical direction of an image. black<128 , white>=128 The function calculates the number of transitions for all Xsize or Ysize and returns the mean of the result Input should be one band, 8-bit.

::: seealso vips_morph(), vips_conv().

Parameters

`nolines`	`double*`
	Output average number of lines.
	The argument will be set by the function.
	The instance takes ownership of the data, and is responsible for freeing it.
`direction`	`VipsDirection`
	Count lines horizontally or vertically.
`...`	`none`
	`NULL`-terminated list of optional named arguments.

Return value

Returns:	`int`
	0 on success, -1 on error.