Method

VipsImageget

Declaration [src]

int
vips_image_get (
  const VipsImage* image,
  const char* name,
  GValue* value_copy
)

Description [src]

Fill value_copy with a copy of the header field. value_copy must be zeroed but uninitialised.

This will return -1 and add a message to the error buffer if the field does not exist. Use vips_image_get_typeof() to test for the existence of a field first if you are not certain it will be there.

For example, to read a double from an image (though of course you would use vips_image_get_double() in practice):

GValue value = { 0 };
double d;

if (vips_image_get (image, name, &value))
  return -1;

if (G_VALUE_TYPE (&value) != G_TYPE_DOUBLE) {
  vips_error( "mydomain",
    _("field \"%s\" is of type %s, not double"),
    name,
    g_type_name (G_VALUE_TYPE (&value)));
  g_value_unset (&value);
  return -1;
}

d = g_value_get_double (&value);
g_value_unset (&value);

See also: vips_image_get_typeof(), vips_image_get_double().

Parameters

`name`	`const char*`
	The name to fetch.
	The data is owned by the caller of the function.
	The value is a NUL terminated UTF-8 string.
`value_copy`	`GValue`
	The %GValue is copied into this.
	The argument will be set by the function.
	The instance takes ownership of the data, and is responsible for freeing it.

Return value

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