/**
* vips_check_dmask_1d: (skip)
* @domain: the originating domain for the error message
* @mask: mask to check
*
* A mask must be one-dimensional (width or height 1).
*
* See also: vips_error().
*
* Returns: 0 if OK, -1 otherwise.
*/
int
vips_check_dmask_1d( const char *domain, DOUBLEMASK *mask )
{
if( vips_check_dmask( domain, mask ) )
return( -1 );
if( mask->xsize != 1 &&
mask->ysize != 1 ) {
vips_error( domain, "%s", _( "mask must be 1D" ) );
return( -1 );
}
return( 0 );
}
/* Break a mask into boxes.
*/
static Boxes *
boxes_new( IMAGE *in, IMAGE *out, DOUBLEMASK *mask, int n_layers, int cluster )
{
const int size = mask->xsize * mask->ysize;
Boxes *boxes;
double sum;
int x, y, z;
/* Check parameters.
*/
if( im_piocheck( in, out ) ||
im_check_uncoded( "im_aconv", in ) ||
vips_check_dmask( "im_aconv", mask ) )
return( NULL );
boxes = VIPS_NEW( out, Boxes );
boxes->in = in;
boxes->out = out;
if( !(boxes->mask = (DOUBLEMASK *) im_local( out,
(im_construct_fn) im_dup_dmask,
(im_callback_fn) im_free_dmask, mask, mask->filename, NULL )) )
return( NULL );
boxes->n_layers = n_layers;
boxes->cluster = cluster;
boxes->n_hline = 0;
boxes->n_velement = 0;
boxes->n_vline = 0;
/* Break into a set of hlines.
*/
if( boxes_break( boxes ) )
return( NULL );
/* Cluster to find groups of lines.
*/
VIPS_DEBUG_MSG( "boxes_new: clustering with thresh %d ...\n", cluster );
while( boxes_cluster2( boxes, cluster ) )
;
/* Renumber to remove holes created by clustering.
*/
boxes_renumber( boxes );
/* Find a set of vlines for the remaining hlines.
*/
boxes_vline( boxes );
/* Find the area of the lines and the length of the longest hline.
*/
boxes->area = 0;
boxes->max_line = 0;
for( y = 0; y < boxes->n_velement; y++ ) {
x = boxes->velement[y].band;
z = boxes->hline[x].end - boxes->hline[x].start;
boxes->area += boxes->velement[y].factor * z;
if( z > boxes->max_line )
boxes->max_line = z;
}
/* Strength reduction: if all lines are divisible by n, we can move
* that n out into the ->area factor. The aim is to produce as many
* factor 1 lines as we can and to reduce the chance of overflow.
*/
x = boxes->velement[0].factor;
for( y = 1; y < boxes->n_velement; y++ )
x = gcd( x, boxes->velement[y].factor );
for( y = 0; y < boxes->n_velement; y++ )
boxes->velement[y].factor /= x;
boxes->area *= x;
/* Find the area of the original mask.
*/
sum = 0;
for( z = 0; z < size; z++ )
sum += mask->coeff[z];
boxes->area = rint( sum * boxes->area / mask->scale );
boxes->rounding = (boxes->area + 1) / 2 + mask->offset * boxes->area;
#ifdef DEBUG
boxes_hprint( boxes );
boxes_vprint( boxes );
#endif /*DEBUG*/
/* With 512x512 tiles, each hline requires 3mb of intermediate per
* thread ... 300 lines is about a gb per thread, ouch.
*/
if( boxes->n_hline > 150 ) {
im_error( "im_aconv", "%s", _( "mask too complex" ) );
return( NULL );
}
return( boxes );
}
