Method

VipsImageimage_get

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 = G_VALUE_INIT;
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() or vips_image_get_double().

Parameters

name

Type: const char*

The name to fetch.

The data is owned by the caller of the method.
The value is a NUL terminated UTF-8 string.
value_copy

Type: GValue

The GValue is copied into this.

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.

Return value

Type: int

0 on success, -1 otherwise.