Changeset 7158

Timestamp:

05/16/11 12:54:11 (13 months ago)

Author:

dustymugs

Message:

Add ST_AsPNG

• added SQL functions for ST_AsPNG
• added regression tests

Associated ticket is #342

Location:

trunk/raster

Files:

• rt_pg/rtpostgis.sql.in.c (modified) (1 diff)
• test/regress/Makefile.in (modified) (1 diff)
• test/regress/rt_aspng_expected (added)
• test/regress/rt_aspng.sql (added)

trunk/raster/rt_pg/rtpostgis.sql.in.c

@@ -1327 +1327 @@
         RETURNS bytea
         AS $$ SELECT st_asjpeg($1, ARRAY[$2], $3) $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+-----------------------------------------------------------------------
+-- ST_AsPNG
+-----------------------------------------------------------------------
+-- Cannot be strict as "options" can be NULL
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, options text[])
+        RETURNS bytea
+        AS $$
+        DECLARE
+                num_bands int;
+                i int;
+                pt text;
+        BEGIN
+                num_bands := st_numbands($1);
+
+                -- PNG only allows 1 or 3 bands
+                IF num_bands > 3 THEN
+                        RAISE NOTICE 'The PNG format only permits one or three bands.  The first three bands will be used.';
+                        rast := st_band(rast, ARRAY[1, 2, 3]);
+                        num_bands := st_numbands(rast);
+                ELSEIF num_bands > 1 THEN
+                        RAISE NOTICE 'The PNG format only permits one or three bands.  The first band will be used.';
+                        rast := st_band(rast, ARRAY[1]);
+                        num_bands := st_numbands(rast);
+                END IF;
+
+                -- PNG only supports 8BUI and 16BUI pixeltype
+                FOR i IN 1..num_bands LOOP
+                        pt = st_bandpixeltype(rast, i);
+                        IF pt != '8BUI' AND pt != '16BUI' THEN
+                                RAISE EXCEPTION 'The pixel type of band % in the raster is not 8BUI or 16BUI.  The PNG format can only be used with 8BUI and 16BUI pixel types.', i;
+                        END IF;
+                END LOOP;
+
+                RETURN st_asgdalraster($1, 'PNG', $2, NULL);
+        END;
+        $$ LANGUAGE 'plpgsql' IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster)
+        RETURNS bytea
+        AS $$ SELECT st_aspng($1, NULL::text[]) $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, nbands int[], options text[])
+        RETURNS bytea
+        AS $$ SELECT st_aspng(st_band($1, $2), $3) $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, nbands int[])
+        RETURNS bytea
+        AS $$ SELECT st_aspng(st_band($1, $2), NULL::text[]) $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, nband int)
+        RETURNS bytea
+        AS $$ SELECT st_aspng(st_band($1, $2)) $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, nbands int[], compression int)
+        RETURNS bytea
+        AS $$
+        DECLARE
+                options text[];
+        BEGIN
+                IF compression IS NOT NULL THEN
+                        IF compression > 9 THEN
+                                compression := 9;
+                        ELSEIF compression < 1 THEN
+                                compression := 1;
+                        END IF;
+
+                        options := array_append(options, 'ZLEVEL=' || compression);
+                END IF;
+
+                RETURN st_aspng(st_band($1, $2), options);
+        END;
+        $$ LANGUAGE 'plpgsql' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, nband int, options text[])
+        RETURNS bytea
+        AS $$ SELECT st_aspng(st_band($1, $2), $3) $$
+        LANGUAGE 'SQL' IMMUTABLE STRICT;
+
+CREATE OR REPLACE FUNCTION st_aspng(rast raster, nband int, compression int)
+        RETURNS bytea
+        AS $$ SELECT st_aspng($1, ARRAY[$2], $3) $$
         LANGUAGE 'SQL' IMMUTABLE STRICT;
 

trunk/raster/test/regress/Makefile.in

@@ -46 +46 @@
         rt_astiff.sql \
         rt_asjpeg.sql \
+        rt_aspng.sql \
         $(NULL)