</sect1>
<sect1 id="Raster_Accessors">
<title>Raster Accessors</title>
- <refentry id="RT_ST_Box2D">
- <refnamediv>
- <refname>ST_Box2D</refname>
- <refpurpose>Returns the box 2d representation of the enclosing box of the raster</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <funcsynopsis>
- <funcprototype>
- <funcdef>box2d <function>ST_Box2D</function></funcdef>
- <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
- </funcprototype>
- </funcsynopsis>
- </refsynopsisdiv>
-
- <refsection>
- <title>Description</title>
-
- <para>Returns the box representing the extent of the raster.</para>
- <para>The polygon is defined by the corner points of the bounding box
- ((<varname>MINX</varname>, <varname>MINY</varname>),
- (<varname>MAXX</varname>, <varname>MAXY</varname>))</para>
- </refsection>
-
- <refsection>
- <title>Examples</title>
-
- <programlisting>SELECT rid, ST_Box2D(rast) As rastbox
-FROM dummy_rast;
-
-rid | rastbox
-----+-------------------------------------------------
-1 | BOX(0.5 0.5,20.5 60.5)
-2 | BOX(3427927.75 5793243.5,3427928 5793244)
- </programlisting>
-
- </refsection>
-
- <refsection>
- <title>See Also</title>
- <para><xref linkend="RT_ST_Envelope" /></para>
- </refsection>
- </refentry>
-
- <refentry id="RT_ST_Envelope">
- <refnamediv>
- <refname>ST_Envelope</refname>
- <refpurpose>Returns the polygon representation of the extent of the raster.</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <funcsynopsis>
- <funcprototype>
- <funcdef>geometry <function>ST_Envelope</function></funcdef>
- <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
- </funcprototype>
- </funcsynopsis>
- </refsynopsisdiv>
-
- <refsection>
- <title>Description</title>
-
- <para>Returns the polygon representation of the extent of the raster in spatial coordinate units defiend by srid. It is a float8 minimum bounding box represented as a polygon. </para>
- <para>The polygon is defined by the corner points of the bounding box
- ((<varname>MINX</varname>, <varname>MINY</varname>),
- (<varname>MINX</varname>, <varname>MAXY</varname>),
- (<varname>MAXX</varname>, <varname>MAXY</varname>),
- (<varname>MAXX</varname>, <varname>MINY</varname>),
- (<varname>MINX</varname>, <varname>MINY</varname>))</para>
- </refsection>
-
- <refsection>
- <title>Examples</title>
-
- <programlisting>SELECT rid, ST_AsText(ST_Envelope(rast)) As envgeomwkt
-FROM dummy_rast;
-
- rid | envgeomwkt
------+--------------------------------------------------------------------
- 1 | POLYGON((0 0,20 0,20 60,0 60,0 0))
- 2 | POLYGON((3427927 5793243,3427928 5793243,
- 3427928 5793244,3427927 5793244, 3427927 5793243))
- </programlisting>
-
- </refsection>
-
- <refsection>
- <title>See Also</title>
- <para><xref linkend="ST_Envelope" />, <xref linkend="ST_AsText" />, <xref linkend="RT_ST_SRID" /></para>
- </refsection>
- </refentry>
-
<refentry id="RT_ST_GeoReference">
<refnamediv>
<refname>ST_GeoReference</refname>
</refsection>
</refentry>
- <refentry id="RT_ST_Value">
- <refnamediv>
- <refname>ST_Value</refname>
- <refpurpose>Returns the value of a given band in a given columnx, rowy pixel. Band numbers start at 1.</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <funcsynopsis>
- <funcprototype>
- <funcdef>integer <function>ST_Value</function></funcdef>
- <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
- <paramdef><type>integer </type> <parameter>bandnum</parameter></paramdef>
- <paramdef><type>integer </type> <parameter>columnx</parameter></paramdef>
- <paramdef><type>integer </type> <parameter>rowy</parameter></paramdef>
- </funcprototype>
- </funcsynopsis>
- </refsynopsisdiv>
-
- <refsection>
- <title>Description</title>
-
- <para>Returns the value of a given band in a given columnx, rowy pixel. Band numbers start at 1.</para>
- <note><para>Note that although the X and Ys of these are not in coordinates of the spatial system,
- you can get that by the following relationship.</para>
- <para>Coordinate upper left ppoint of a row column
- is:
- ST_SetSRID(ST_Point(ST_UpperLeftX(rast) + ST_PixelSizeX(rast)*columnx, ST_UpperLeftY(rast) + ST_PixelSizeY(rast)*columny), ST_SRID(rast))
- </para>
- <para>If you want the pixel box instead of the upper left point, you can use the ST_MakeEnvelope function and
- translate it every x,y.</para>
- <para>Also note that many of these examples particular the intersection example can be more
- simply done with the planned functions that are not currently available.</para>
-
- <para>If you are looking for a function that will take a geometry point and return a pixel value, this is in the works, for now
- you can use a user contributed function <ulink url="http://trac.osgeo.org/postgis/wiki/UsersWikiwktrasterfunctions">upgis_ptval</ulink>
- </para>
- </note>
-
- </refsection>
-
- <refsection>
- <title>Examples</title>
-
- <programlisting>
-SELECt rid, ST_Value(rast, 1,1,1) As b1pval,
- ST_Value(rast, 2,1,1) As b2pval, ST_Value(rast, 3,1,1) As b3pval
-FROM dummy_rast
-WHERE rid=2;
-
- rid | b1pval | b2pval | b3pval
------+--------+--------+--------
- 2 | 253 | 78 | 70
- </programlisting>
-
- <programlisting>
---- Get all values in bands 1,2,3 of each pixel --
-SELECT x, y, ST_Value(rast, 1, x, y) As b1val,
- ST_Value(rast, 2, x, y) As b2val, ST_Value(rast, 3, x, y) As b3val
-FROM dummy_rast CROSS JOIN
-generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y
-WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast);
-
- x | y | b1val | b2val | b3val
----+---+-------+-------+-------
- 1 | 1 | 253 | 78 | 70
- 1 | 2 | 253 | 96 | 80
- 1 | 3 | 250 | 99 | 90
- 1 | 4 | 251 | 89 | 77
- 1 | 5 | 252 | 79 | 62
- 2 | 1 | 254 | 98 | 86
- 2 | 2 | 254 | 118 | 108
- :
- :
- </programlisting>
-
- <programlisting>
---- Get all values in bands 1,2,3 of each pixel same as above but returning the upper left point point of each pixel --
-SELECT ST_AsText(ST_SetSRID(
- ST_Point(ST_UpperLeftX(rast) + ST_PixelSizeX(rast)*x,
- ST_UpperLeftY(rast) + ST_PixelSizeY(rast)*y),
- ST_SRID(rast))) As uplpt
- , ST_Value(rast, 1, x, y) As b1val,
- ST_Value(rast, 2, x, y) As b2val, ST_Value(rast, 3, x, y) As b3val
-FROM dummy_rast CROSS JOIN
-generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y
-WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast);
-
- uplpt | b1val | b2val | b3val
------------------------------+-------+-------+-------
- POINT(3427929.25 5793245.5) | 253 | 78 | 70
- POINT(3427929.25 5793247) | 253 | 96 | 80
- POINT(3427929.25 5793248.5) | 250 | 99 | 90
-:
- </programlisting>
- <programlisting>
---- Get a polygon formed by union of all pixels
- that fall in a particular value range and intersect particular polygon --
-SELECT ST_AsText(ST_Union(pixpolyg)) As shadow
-FROM (SELECT ST_Translate(ST_MakeEnvelope(
- ST_UpperLeftX(rast), ST_UpperLeftY(rast),
- ST_UpperLeftX(rast) + ST_PixelSizeX(rast),
- ST_UpperLeftY(rast) + ST_PixelSizeY(rast), 0
- ), ST_PixelSizeX(rast)*x, ST_PixelSizeY(rast)*y
- ) As pixpolyg, ST_Value(rast, 2, x, y) As b2val
- FROM dummy_rast CROSS JOIN
-generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y
-WHERE rid = 2
- AND x <= ST_Width(rast) AND y <= ST_Height(rast)) As foo
-WHERE
- ST_Intersects(
- pixpolyg,
- ST_GeomFromText('POLYGON((3427928 5793244,3427927.75 5793243.75,3427928 5793243.75,3427928 5793244))',0)
- ) AND b2val != 254;
-
-
- shadow
-------------------------------------------------------------------------------------
- MULTIPOLYGON(((3427928 5793243.9,3427928 5793243.85,3427927.95 5793243.85,3427927.95 5793243.9,
- 3427927.95 5793243.95,3427928 5793243.95,3427928.05 5793243.95,3427928.05 5793243.9,3427928 5793243.9)),((3427927.95 5793243.9,3427927.95 579324
-3.85,3427927.9 5793243.85,3427927.85 5793243.85,3427927.85 5793243.9,3427927.9 5793243.9,3427927.9 5793243.95,
-3427927.95 5793243.95,3427927.95 5793243.9)),((3427927.85 5793243.75,3427927.85 5793243.7,3427927.8 5793243.7,3427927.8 5793243.75
-,3427927.8 5793243.8,3427927.8 5793243.85,3427927.85 5793243.85,3427927.85 5793243.8,3427927.85 5793243.75)),
-((3427928.05 5793243.75,3427928.05 5793243.7,3427928 5793243.7,3427927.95 5793243.7,3427927.95 5793243.75,3427927.95 5793243.8,3427
-927.95 5793243.85,3427928 5793243.85,3427928 5793243.8,3427928.05 5793243.8,
-3427928.05 5793243.75)),((3427927.95 5793243.75,3427927.95 5793243.7,3427927.9 5793243.7,3427927.85 5793243.7,
-3427927.85 5793243.75,3427927.85 5793243.8,3427927.85 5793243.85,3427927.9 5793243.85,
-3427927.95 5793243.85,3427927.95 5793243.8,3427927.95 5793243.75)))
- </programlisting>
-
- <programlisting>
---- Checking all the pixels of a large raster tile can take a long time.
---- You can dramatically improve speed at some lose of precision by orders of magnitude
--- by sampling pixels using the step optional parameter of generate_series.
--- This next example does the same as previous but by checking 1 for every 4 (2x2) pixels and putting in the last checked
--- putting in the checked pixel as the value for subsequent 4
-
-SELECT ST_AsText(ST_Union(pixpolyg)) As shadow
-FROM (SELECT ST_Translate(ST_MakeEnvelope(
- ST_UpperLeftX(rast), ST_UpperLeftY(rast),
- ST_UpperLeftX(rast) + ST_PixelSizeX(rast)*2,
- ST_UpperLeftY(rast) + ST_PixelSizeY(rast)*2, 0
- ), ST_PixelSizeX(rast)*x, ST_PixelSizeY(rast)*y
- ) As pixpolyg, ST_Value(rast, 2, x, y) As b2val
- FROM dummy_rast CROSS JOIN
-generate_series(1,1000,2) As x CROSS JOIN generate_series(1,1000,2) As y
-WHERE rid = 2
- AND x <= ST_Width(rast) AND y <= ST_Height(rast) ) As foo
-WHERE
- ST_Intersects(
- pixpolyg,
- ST_GeomFromText('POLYGON((3427928 5793244,3427927.75 5793243.75,3427928 5793243.75,3427928 5793244))',0)
- ) AND b2val != 254;
-
- shadow
-------------------------------------------------------------------------------------
- MULTIPOLYGON(((3427927.9 5793243.85,3427927.8 5793243.85,3427927.8 5793243.95,
- 3427927.9 5793243.95,3427928 5793243.95,3427928.1 5793243.95,3427928.1 5793243.85,3427928 5793243.85,3427927.9 5793243.85)),
- ((3427927.9 5793243.65,3427927.8 5793243.65,3427927.8 5793243.75,3427927.8 5793243.85,3427927.9 5793243.85,
- 3427928 5793243.85,3427928 5793243.75,3427928.1 5793243.75,3427928.1 5793243.65,3427928 5793243.65,3427927.9 5793243.65)))
- </programlisting>
- </refsection>
-
- <refsection>
- <title>See Also</title>
- <para><xref linkend="RT_ST_NumBands" />, <xref linkend="RT_ST_PixelSizeX" />,
- , <xref linkend="RT_ST_PixelSizeY" />, <xref linkend="RT_ST_UpperLeftX" />,
- <xref linkend="RT_ST_UpperLeftY" />, <xref linkend="RT_ST_SRID" />, <xref linkend="ST_AsText" />,
- , <xref linkend="ST_Point" />, <xref linkend="ST_MakeEnvelope" />,
- <xref linkend="ST_Intersects" /></para>
- </refsection>
- </refentry>
<refentry id="RT_ST_Width">
<refnamediv>
</refsection>
<refsection>
- <title>Examples</title>
+ <title>Examples</title>
+
+ <programlisting>SELECT ST_BandPixelType(rast,1) As btype1,
+ ST_BandPixelType(rast,2) As btype2, ST_BandPixelType(rast,3) As btype3
+FROM dummy_rast
+WHERE rid = 2;
+
+ btype1 | btype2 | btype3
+--------+--------+--------
+ 8BUI | 8BUI | 8BUI
+ </programlisting>
+
+ </refsection>
+
+ <refsection>
+ <title>See Also</title>
+ <para><xref linkend="RT_ST_NumBands" /></para>
+ </refsection>
+ </refentry>
+
+ </sect1>
+
+ <sect1 id="Raster_Pixel_Accessors">
+ <title>Raster Pixel Accessors</title>
+
+ <refentry id="RT_ST_Value">
+ <refnamediv>
+ <refname>ST_Value</refname>
+ <refpurpose>Returns the value of a given band in a given columnx, rowy pixel. Band numbers start at 1.</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>integer <function>ST_Value</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>bandnum</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>columnx</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>rowy</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsection>
+ <title>Description</title>
- <programlisting>SELECT ST_BandPixelType(rast,1) As btype1,
- ST_BandPixelType(rast,2) As btype2, ST_BandPixelType(rast,3) As btype3
+ <para>Returns the value of a given band in a given columnx, rowy pixel. Band numbers start at 1.</para>
+ <note><para>Note that although the X and Ys of these are not in coordinates of the spatial system,
+ you can get that by the following relationship.</para>
+ <para>Coordinate upper left ppoint of a row column
+ is:
+ ST_SetSRID(ST_Point(ST_UpperLeftX(rast) + ST_PixelSizeX(rast)*columnx, ST_UpperLeftY(rast) + ST_PixelSizeY(rast)*columny), ST_SRID(rast))
+ </para>
+ <para>If you want the pixel box instead of the upper left point, you can use the ST_MakeEnvelope function and
+ translate it every x,y.</para>
+ <para>Also note that many of these examples particular the intersection example can be more
+ simply done with the planned functions that are not currently available.</para>
+
+ <para>If you are looking for a function that will take a geometry point and return a pixel value, this is in the works, for now
+ you can use a user contributed function <ulink url="http://trac.osgeo.org/postgis/wiki/UsersWikiwktrasterfunctions">upgis_ptval</ulink>
+ </para>
+ </note>
+
+ </refsection>
+
+ <refsection>
+ <title>Examples</title>
+
+ <programlisting>
+SELECt rid, ST_Value(rast, 1,1,1) As b1pval,
+ ST_Value(rast, 2,1,1) As b2pval, ST_Value(rast, 3,1,1) As b3pval
FROM dummy_rast
-WHERE rid = 2;
+WHERE rid=2;
- btype1 | btype2 | btype3
---------+--------+--------
- 8BUI | 8BUI | 8BUI
+ rid | b1pval | b2pval | b3pval
+-----+--------+--------+--------
+ 2 | 253 | 78 | 70
+ </programlisting>
+
+ <programlisting>
+--- Get all values in bands 1,2,3 of each pixel --
+SELECT x, y, ST_Value(rast, 1, x, y) As b1val,
+ ST_Value(rast, 2, x, y) As b2val, ST_Value(rast, 3, x, y) As b3val
+FROM dummy_rast CROSS JOIN
+generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y
+WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast);
+
+ x | y | b1val | b2val | b3val
+---+---+-------+-------+-------
+ 1 | 1 | 253 | 78 | 70
+ 1 | 2 | 253 | 96 | 80
+ 1 | 3 | 250 | 99 | 90
+ 1 | 4 | 251 | 89 | 77
+ 1 | 5 | 252 | 79 | 62
+ 2 | 1 | 254 | 98 | 86
+ 2 | 2 | 254 | 118 | 108
+ :
+ :
+ </programlisting>
+
+ <programlisting>
+--- Get all values in bands 1,2,3 of each pixel same as above but returning the upper left point point of each pixel --
+SELECT ST_AsText(ST_SetSRID(
+ ST_Point(ST_UpperLeftX(rast) + ST_PixelSizeX(rast)*x,
+ ST_UpperLeftY(rast) + ST_PixelSizeY(rast)*y),
+ ST_SRID(rast))) As uplpt
+ , ST_Value(rast, 1, x, y) As b1val,
+ ST_Value(rast, 2, x, y) As b2val, ST_Value(rast, 3, x, y) As b3val
+FROM dummy_rast CROSS JOIN
+generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y
+WHERE rid = 2 AND x <= ST_Width(rast) AND y <= ST_Height(rast);
+
+ uplpt | b1val | b2val | b3val
+-----------------------------+-------+-------+-------
+ POINT(3427929.25 5793245.5) | 253 | 78 | 70
+ POINT(3427929.25 5793247) | 253 | 96 | 80
+ POINT(3427929.25 5793248.5) | 250 | 99 | 90
+:
+ </programlisting>
+ <programlisting>
+--- Get a polygon formed by union of all pixels
+ that fall in a particular value range and intersect particular polygon --
+SELECT ST_AsText(ST_Union(pixpolyg)) As shadow
+FROM (SELECT ST_Translate(ST_MakeEnvelope(
+ ST_UpperLeftX(rast), ST_UpperLeftY(rast),
+ ST_UpperLeftX(rast) + ST_PixelSizeX(rast),
+ ST_UpperLeftY(rast) + ST_PixelSizeY(rast), 0
+ ), ST_PixelSizeX(rast)*x, ST_PixelSizeY(rast)*y
+ ) As pixpolyg, ST_Value(rast, 2, x, y) As b2val
+ FROM dummy_rast CROSS JOIN
+generate_series(1,1000) As x CROSS JOIN generate_series(1,1000) As y
+WHERE rid = 2
+ AND x <= ST_Width(rast) AND y <= ST_Height(rast)) As foo
+WHERE
+ ST_Intersects(
+ pixpolyg,
+ ST_GeomFromText('POLYGON((3427928 5793244,3427927.75 5793243.75,3427928 5793243.75,3427928 5793244))',0)
+ ) AND b2val != 254;
+
+
+ shadow
+------------------------------------------------------------------------------------
+ MULTIPOLYGON(((3427928 5793243.9,3427928 5793243.85,3427927.95 5793243.85,3427927.95 5793243.9,
+ 3427927.95 5793243.95,3427928 5793243.95,3427928.05 5793243.95,3427928.05 5793243.9,3427928 5793243.9)),((3427927.95 5793243.9,3427927.95 579324
+3.85,3427927.9 5793243.85,3427927.85 5793243.85,3427927.85 5793243.9,3427927.9 5793243.9,3427927.9 5793243.95,
+3427927.95 5793243.95,3427927.95 5793243.9)),((3427927.85 5793243.75,3427927.85 5793243.7,3427927.8 5793243.7,3427927.8 5793243.75
+,3427927.8 5793243.8,3427927.8 5793243.85,3427927.85 5793243.85,3427927.85 5793243.8,3427927.85 5793243.75)),
+((3427928.05 5793243.75,3427928.05 5793243.7,3427928 5793243.7,3427927.95 5793243.7,3427927.95 5793243.75,3427927.95 5793243.8,3427
+927.95 5793243.85,3427928 5793243.85,3427928 5793243.8,3427928.05 5793243.8,
+3427928.05 5793243.75)),((3427927.95 5793243.75,3427927.95 5793243.7,3427927.9 5793243.7,3427927.85 5793243.7,
+3427927.85 5793243.75,3427927.85 5793243.8,3427927.85 5793243.85,3427927.9 5793243.85,
+3427927.95 5793243.85,3427927.95 5793243.8,3427927.95 5793243.75)))
+ </programlisting>
+
+ <programlisting>
+--- Checking all the pixels of a large raster tile can take a long time.
+--- You can dramatically improve speed at some lose of precision by orders of magnitude
+-- by sampling pixels using the step optional parameter of generate_series.
+-- This next example does the same as previous but by checking 1 for every 4 (2x2) pixels and putting in the last checked
+-- putting in the checked pixel as the value for subsequent 4
+
+SELECT ST_AsText(ST_Union(pixpolyg)) As shadow
+FROM (SELECT ST_Translate(ST_MakeEnvelope(
+ ST_UpperLeftX(rast), ST_UpperLeftY(rast),
+ ST_UpperLeftX(rast) + ST_PixelSizeX(rast)*2,
+ ST_UpperLeftY(rast) + ST_PixelSizeY(rast)*2, 0
+ ), ST_PixelSizeX(rast)*x, ST_PixelSizeY(rast)*y
+ ) As pixpolyg, ST_Value(rast, 2, x, y) As b2val
+ FROM dummy_rast CROSS JOIN
+generate_series(1,1000,2) As x CROSS JOIN generate_series(1,1000,2) As y
+WHERE rid = 2
+ AND x <= ST_Width(rast) AND y <= ST_Height(rast) ) As foo
+WHERE
+ ST_Intersects(
+ pixpolyg,
+ ST_GeomFromText('POLYGON((3427928 5793244,3427927.75 5793243.75,3427928 5793243.75,3427928 5793244))',0)
+ ) AND b2val != 254;
+
+ shadow
+------------------------------------------------------------------------------------
+ MULTIPOLYGON(((3427927.9 5793243.85,3427927.8 5793243.85,3427927.8 5793243.95,
+ 3427927.9 5793243.95,3427928 5793243.95,3427928.1 5793243.95,3427928.1 5793243.85,3427928 5793243.85,3427927.9 5793243.85)),
+ ((3427927.9 5793243.65,3427927.8 5793243.65,3427927.8 5793243.75,3427927.8 5793243.85,3427927.9 5793243.85,
+ 3427928 5793243.85,3427928 5793243.75,3427928.1 5793243.75,3427928.1 5793243.65,3427928 5793243.65,3427927.9 5793243.65)))
</programlisting>
-
</refsection>
<refsection>
<title>See Also</title>
- <para><xref linkend="RT_ST_NumBands" /></para>
+ <para><xref linkend="RT_ST_NumBands" />, <xref linkend="RT_ST_PixelSizeX" />,
+ , <xref linkend="RT_ST_PixelSizeY" />, <xref linkend="RT_ST_UpperLeftX" />,
+ <xref linkend="RT_ST_UpperLeftY" />, <xref linkend="RT_ST_SRID" />, <xref linkend="ST_AsText" />,
+ , <xref linkend="ST_Point" />, <xref linkend="ST_MakeEnvelope" />,
+ <xref linkend="ST_Intersects" /></para>
</refsection>
</refentry>
-
</sect1>
+
<sect1 id="Raster_Editors">
<title>Raster Editors</title>
<refentry id="RT_ST_SetBandHasNoDataValue">
<sect1 id="Raster_Processing">
<title>Raster Processing Functions</title>
+ <refentry id="RT_ST_Box2D">
+ <refnamediv>
+ <refname>ST_Box2D</refname>
+ <refpurpose>Returns the box 2d representation of the enclosing box of the raster</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>box2d <function>ST_Box2D</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsection>
+ <title>Description</title>
+
+ <para>Returns the box representing the extent of the raster.</para>
+ <para>The polygon is defined by the corner points of the bounding box
+ ((<varname>MINX</varname>, <varname>MINY</varname>),
+ (<varname>MAXX</varname>, <varname>MAXY</varname>))</para>
+ </refsection>
+
+ <refsection>
+ <title>Examples</title>
+
+ <programlisting>SELECT rid, ST_Box2D(rast) As rastbox
+FROM dummy_rast;
+
+rid | rastbox
+----+-------------------------------------------------
+1 | BOX(0.5 0.5,20.5 60.5)
+2 | BOX(3427927.75 5793243.5,3427928 5793244)
+ </programlisting>
+
+ </refsection>
+
+ <refsection>
+ <title>See Also</title>
+ <para><xref linkend="RT_ST_Envelope" /></para>
+ </refsection>
+ </refentry>
+
<refentry id="RT_ST_ConvexHull">
<refnamediv>
<refname>ST_ConvexHull</refname>
<para><xref linkend="RT_ST_Value" /></para>
</refsection>
</refentry>
+
+ <refentry id="RT_ST_Envelope">
+ <refnamediv>
+ <refname>ST_Envelope</refname>
+ <refpurpose>Returns the polygon representation of the extent of the raster.</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>geometry <function>ST_Envelope</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsection>
+ <title>Description</title>
+
+ <para>Returns the polygon representation of the extent of the raster in spatial coordinate units defiend by srid. It is a float8 minimum bounding box represented as a polygon. </para>
+ <para>The polygon is defined by the corner points of the bounding box
+ ((<varname>MINX</varname>, <varname>MINY</varname>),
+ (<varname>MINX</varname>, <varname>MAXY</varname>),
+ (<varname>MAXX</varname>, <varname>MAXY</varname>),
+ (<varname>MAXX</varname>, <varname>MINY</varname>),
+ (<varname>MINX</varname>, <varname>MINY</varname>))</para>
+ </refsection>
+
+ <refsection>
+ <title>Examples</title>
+
+ <programlisting>SELECT rid, ST_AsText(ST_Envelope(rast)) As envgeomwkt
+FROM dummy_rast;
+
+ rid | envgeomwkt
+-----+--------------------------------------------------------------------
+ 1 | POLYGON((0 0,20 0,20 60,0 60,0 0))
+ 2 | POLYGON((3427927 5793243,3427928 5793243,
+ 3427928 5793244,3427927 5793244, 3427927 5793243))
+ </programlisting>
+
+ </refsection>
+
+ <refsection>
+ <title>See Also</title>
+ <para><xref linkend="ST_Envelope" />, <xref linkend="ST_AsText" />, <xref linkend="RT_ST_SRID" /></para>
+ </refsection>
+ </refentry>
</sect1>
<sect1 id="RT_Operators">
projects / postgis / commitdiff