/* Process the first @n bands with @fn, detach and reattach remaining bands. */ static int vips_process_n( const char *domain, VipsImage *in, VipsImage **out, int n, VipsColourTransformFn fn ) { if( in->Bands > n ) { VipsImage *scope = vips_image_new(); VipsImage **t = (VipsImage **) vips_object_local_array( VIPS_OBJECT( scope ), 4 ); if( vips_extract_band( in, &t[0], 0, "n", n, NULL ) || vips_extract_band( in, &t[1], n, "n", in->Bands - n, NULL ) || fn( t[0], &t[2], NULL ) || vips_cast( t[1], &t[3], t[2]->BandFmt, NULL ) || vips_bandjoin2( t[2], t[3], out, NULL ) ) { g_object_unref( scope ); return( -1 ); } g_object_unref( scope ); } else if( in->Bands == n ) { if( fn( in, out, NULL ) ) return( -1 ); } else { vips_error( domain, "%s", _( "too few bands for operation" ) ); return( -1 ); } return( 0 ); }
/* Calculate sqrt(b1^2 + b2^2 ...) */ static int pythagoras( VipsSmartcrop *smartcrop, VipsImage *in, VipsImage **out ) { VipsImage **t = (VipsImage **) vips_object_local_array( VIPS_OBJECT( smartcrop ), 2 * in->Bands + 1 ); int i; for( i = 0; i < in->Bands; i++ ) if( vips_extract_band( in, &t[i], i, NULL ) ) return( -1 ); for( i = 0; i < in->Bands; i++ ) if( vips_multiply( t[i], t[i], &t[i + in->Bands], NULL ) ) return( -1 ); if( vips_sum( &t[in->Bands], &t[2 * in->Bands], in->Bands, NULL ) || vips_pow_const1( t[2 * in->Bands], out, 0.5, NULL ) ) return( -1 ); return( 0 ); }
static int vips_smartcrop_attention( VipsSmartcrop *smartcrop, VipsImage *in, int *left, int *top ) { /* From smartcrop.js. */ static double skin_vector[] = {-0.78, -0.57, -0.44}; static double ones[] = {1.0, 1.0, 1.0}; VipsImage **t = (VipsImage **) vips_object_local_array( VIPS_OBJECT( smartcrop ), 24 ); double hscale; double vscale; double sigma; double max; int x_pos; int y_pos; /* The size we shrink to gives the precision with which we can place * the crop */ hscale = 32.0 / in->Xsize; vscale = 32.0 / in->Ysize; sigma = VIPS_MAX( sqrt( pow( smartcrop->width * hscale, 2 ) + pow( smartcrop->height * vscale, 2 ) ) / 10, 1.0 ); if ( vips_resize( in, &t[17], hscale, "vscale", vscale, NULL ) ) return( -1 ); /* Simple edge detect. */ if( !(t[21] = vips_image_new_matrixv( 3, 3, 0.0, -1.0, 0.0, -1.0, 4.0, -1.0, 0.0, -1.0, 0.0 )) ) return( -1 ); /* Convert to XYZ and just use the first three bands. */ if( vips_colourspace( t[17], &t[0], VIPS_INTERPRETATION_XYZ, NULL ) || vips_extract_band( t[0], &t[1], 0, "n", 3, NULL ) ) return( -1 ); /* Edge detect on Y. */ if( vips_extract_band( t[1], &t[2], 1, NULL ) || vips_conv( t[2], &t[3], t[21], "precision", VIPS_PRECISION_INTEGER, NULL ) || vips_linear1( t[3], &t[4], 5.0, 0.0, NULL ) || vips_abs( t[4], &t[14], NULL ) ) return( -1 ); /* Look for skin colours. Taken from smartcrop.js. */ if( /* Normalise to magnitude of colour in XYZ. */ pythagoras( smartcrop, t[1], &t[5] ) || vips_divide( t[1], t[5], &t[6], NULL ) || /* Distance from skin point. */ vips_linear( t[6], &t[7], ones, skin_vector, 3, NULL ) || pythagoras( smartcrop, t[7], &t[8] ) || /* Rescale to 100 - 0 score. */ vips_linear1( t[8], &t[9], -100.0, 100.0, NULL ) || /* Ignore dark areas. */ vips_more_const1( t[2], &t[10], 5.0, NULL ) || !(t[11] = vips_image_new_from_image1( t[10], 0.0 )) || vips_ifthenelse( t[10], t[9], t[11], &t[15], NULL ) ) return( -1 ); /* Look for saturated areas. */ if( vips_colourspace( t[1], &t[12], VIPS_INTERPRETATION_LAB, NULL ) || vips_extract_band( t[12], &t[13], 1, NULL ) || vips_ifthenelse( t[10], t[13], t[11], &t[16], NULL ) ) return( -1 ); /* Sum, blur and find maxpos. * * The amount of blur is related to the size of the crop * area: how large an area we want to consider for the scoring * function. */ if( vips_sum( &t[14], &t[18], 3, NULL ) || vips_gaussblur( t[18], &t[19], sigma, NULL ) || vips_max( t[19], &max, "x", &x_pos, "y", &y_pos, NULL ) ) return( -1 ); /* Centre the crop over the max. */ *left = VIPS_CLIP( 0, x_pos / hscale - smartcrop->width / 2, in->Xsize - smartcrop->width ); *top = VIPS_CLIP( 0, y_pos / vscale - smartcrop->height / 2, in->Ysize - smartcrop->height ); return( 0 ); }