Raster Pixel Accessors and Setters
ST_PixelAsPolygon
Returns the polygon geometry that bounds the pixel for a particular row and column.
Synopsis
geometry ST_PixelAsPolygon(raster rast, integer columnx, integer rowy)
Description
Returns the polygon geometry that bounds the pixel for a particular row and column.
Availability: 2.0.0
Examples
-- get raster pixel polygon
SELECT i,j, ST_AsText(ST_PixelAsPolygon(foo.rast, i,j)) As b1pgeom
FROM dummy_rast As foo
CROSS JOIN generate_series(1,2) As i
CROSS JOIN generate_series(1,1) As j
WHERE rid=2;
i | j | b1pgeom
---+---+-----------------------------------------------------------------------------
1 | 1 | POLYGON((3427927.75 5793244,3427927.8 5793244,3427927.8 5793243.95,...
2 | 1 | POLYGON((3427927.8 5793244,3427927.85 5793244,3427927.85 5793243.95, ..
See Also
RT_ST_DumpAsPolygons, RT_ST_PixelAsPolygons, RT_ST_PixelAsPoint, RT_ST_PixelAsPoints, RT_ST_PixelAsCentroid, RT_ST_PixelAsCentroids, RT_ST_Intersection, ST_AsText
ST_PixelAsPolygons
Returns the polygon geometry that bounds every pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel.
Synopsis
setof record ST_PixelAsPolygons(raster rast, integer band=1, boolean exclude_nodata_value=TRUE)
Description
Returns the polygon geometry that bounds every pixel of a raster band along with the value (double precision), the X and the Y raster coordinates (integers) of each pixel.
Return record format: geom geometry, val double precision, x integer, y integers.
Note
When exclude_nodata_value = TRUE, only those pixels whose values are not NODATA are returned as points.
Note
ST_PixelAsPolygons returns one polygon geometry for every pixel. This is different than ST_DumpAsPolygons where each geometry represents one or more pixels with the same pixel value.
Availability: 2.0.0
Enhanced: 2.1.0 exclude_nodata_value optional argument was added.
Changed: 2.1.1 Changed behavior of exclude_nodata_value.
Examples
-- get raster pixel polygon
SELECT (gv).x, (gv).y, (gv).val, ST_AsText((gv).geom) geom
FROM (SELECT ST_PixelAsPolygons(
ST_SetValue(ST_SetValue(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0, 0, 0.001, -0.001, 0.001, 0.001, 4269),
'8BUI'::text, 1, 0),
2, 2, 10),
1, 1, NULL)
) gv
) foo;
x | y | val | geom
---+---+-----------------------------------------------------------------------------
1 | 1 | | POLYGON((0 0,0.001 0.001,0.002 0,0.001 -0.001,0 0))
1 | 2 | 1 | POLYGON((0.001 -0.001,0.002 0,0.003 -0.001,0.002 -0.002,0.001 -0.001))
2 | 1 | 1 | POLYGON((0.001 0.001,0.002 0.002,0.003 0.001,0.002 0,0.001 0.001))
2 | 2 | 10 | POLYGON((0.002 0,0.003 0.001,0.004 0,0.003 -0.001,0.002 0))
See Also
RT_ST_DumpAsPolygons, RT_ST_PixelAsPolygon, RT_ST_PixelAsPoint, RT_ST_PixelAsPoints, RT_ST_PixelAsCentroid, RT_ST_PixelAsCentroids, ST_AsText
ST_PixelAsPoint
Returns a point geometry of the pixel's upper-left corner.
Synopsis
geometry ST_PixelAsPoint(raster rast, integer columnx, integer rowy)
Description
Returns a point geometry of the pixel's upper-left corner.
Availability: 2.1.0
Examples
SELECT ST_AsText(ST_PixelAsPoint(rast, 1, 1)) FROM dummy_rast WHERE rid = 1;
st_astext
----------------
POINT(0.5 0.5)
See Also
RT_ST_DumpAsPolygons, RT_ST_PixelAsPolygon, RT_ST_PixelAsPolygons, RT_ST_PixelAsPoints, RT_ST_PixelAsCentroid, RT_ST_PixelAsCentroids
ST_PixelAsPoints
Returns a point geometry for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The coordinates of the point geometry are of the pixel's upper-left corner.
Synopsis
setof record ST_PixelAsPoints(raster rast, integer band=1, boolean exclude_nodata_value=TRUE)
Description
Returns a point geometry for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The coordinates of the point geometry are of the pixel's upper-left corner.
Return record format: geom geometry, val double precision, x integer, y integers.
Note
When exclude_nodata_value = TRUE, only those pixels whose values are not NODATA are returned as points.
Availability: 2.1.0
Changed: 2.1.1 Changed behavior of exclude_nodata_value.
Examples
SELECT x, y, val, ST_AsText(geom) FROM (SELECT (ST_PixelAsPoints(rast, 1)).* FROM dummy_rast WHERE rid = 2) foo;
x | y | val | st_astext
---+---+-----+------------------------------
1 | 1 | 253 | POINT(3427927.75 5793244)
2 | 1 | 254 | POINT(3427927.8 5793244)
3 | 1 | 253 | POINT(3427927.85 5793244)
4 | 1 | 254 | POINT(3427927.9 5793244)
5 | 1 | 254 | POINT(3427927.95 5793244)
1 | 2 | 253 | POINT(3427927.75 5793243.95)
2 | 2 | 254 | POINT(3427927.8 5793243.95)
3 | 2 | 254 | POINT(3427927.85 5793243.95)
4 | 2 | 253 | POINT(3427927.9 5793243.95)
5 | 2 | 249 | POINT(3427927.95 5793243.95)
1 | 3 | 250 | POINT(3427927.75 5793243.9)
2 | 3 | 254 | POINT(3427927.8 5793243.9)
3 | 3 | 254 | POINT(3427927.85 5793243.9)
4 | 3 | 252 | POINT(3427927.9 5793243.9)
5 | 3 | 249 | POINT(3427927.95 5793243.9)
1 | 4 | 251 | POINT(3427927.75 5793243.85)
2 | 4 | 253 | POINT(3427927.8 5793243.85)
3 | 4 | 254 | POINT(3427927.85 5793243.85)
4 | 4 | 254 | POINT(3427927.9 5793243.85)
5 | 4 | 253 | POINT(3427927.95 5793243.85)
1 | 5 | 252 | POINT(3427927.75 5793243.8)
2 | 5 | 250 | POINT(3427927.8 5793243.8)
3 | 5 | 254 | POINT(3427927.85 5793243.8)
4 | 5 | 254 | POINT(3427927.9 5793243.8)
5 | 5 | 254 | POINT(3427927.95 5793243.8)
See Also
RT_ST_DumpAsPolygons, RT_ST_PixelAsPolygon, RT_ST_PixelAsPolygons, RT_ST_PixelAsPoint, RT_ST_PixelAsCentroid, RT_ST_PixelAsCentroids
ST_PixelAsCentroid
Returns the centroid (point geometry) of the area represented by a pixel.
Synopsis
geometry ST_PixelAsCentroid(raster rast, integer x, integer y)
Description
Returns the centroid (point geometry) of the area represented by a pixel.
Enhanced: 3.2.0 Faster now implemented in C.
Availability: 2.1.0
Examples
SELECT ST_AsText(ST_PixelAsCentroid(rast, 1, 1)) FROM dummy_rast WHERE rid = 1;
st_astext
--------------
POINT(1.5 2)
See Also
RT_ST_DumpAsPolygons, RT_ST_PixelAsPolygon, RT_ST_PixelAsPolygons, RT_ST_PixelAsPoint, RT_ST_PixelAsPoints, RT_ST_PixelAsCentroids
ST_PixelAsCentroids
Returns the centroid (point geometry) for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The point geometry is the centroid of the area represented by a pixel.
Synopsis
setof record ST_PixelAsCentroids(raster rast, integer band=1, boolean exclude_nodata_value=TRUE)
Description
Returns the centroid (point geometry) for each pixel of a raster band along with the value, the X and the Y raster coordinates of each pixel. The point geometry is the centroid of the area represented by a pixel.
Return record format: geom geometry, val double precision, x integer, y integers.
Note
When exclude_nodata_value = TRUE, only those pixels whose values are not NODATA are returned as points.
Enhanced: 3.2.0 Faster now implemented in C.
Changed: 2.1.1 Changed behavior of exclude_nodata_value.
Availability: 2.1.0
Examples
--LATERAL syntax requires PostgreSQL 9.3+
SELECT x, y, val, ST_AsText(geom)
FROM (SELECT dp.* FROM dummy_rast, LATERAL ST_PixelAsCentroids(rast, 1) AS dp WHERE rid = 2) foo;
x | y | val | st_astext
---+---+-----+--------------------------------
1 | 1 | 253 | POINT(3427927.775 5793243.975)
2 | 1 | 254 | POINT(3427927.825 5793243.975)
3 | 1 | 253 | POINT(3427927.875 5793243.975)
4 | 1 | 254 | POINT(3427927.925 5793243.975)
5 | 1 | 254 | POINT(3427927.975 5793243.975)
1 | 2 | 253 | POINT(3427927.775 5793243.925)
2 | 2 | 254 | POINT(3427927.825 5793243.925)
3 | 2 | 254 | POINT(3427927.875 5793243.925)
4 | 2 | 253 | POINT(3427927.925 5793243.925)
5 | 2 | 249 | POINT(3427927.975 5793243.925)
1 | 3 | 250 | POINT(3427927.775 5793243.875)
2 | 3 | 254 | POINT(3427927.825 5793243.875)
3 | 3 | 254 | POINT(3427927.875 5793243.875)
4 | 3 | 252 | POINT(3427927.925 5793243.875)
5 | 3 | 249 | POINT(3427927.975 5793243.875)
1 | 4 | 251 | POINT(3427927.775 5793243.825)
2 | 4 | 253 | POINT(3427927.825 5793243.825)
3 | 4 | 254 | POINT(3427927.875 5793243.825)
4 | 4 | 254 | POINT(3427927.925 5793243.825)
5 | 4 | 253 | POINT(3427927.975 5793243.825)
1 | 5 | 252 | POINT(3427927.775 5793243.775)
2 | 5 | 250 | POINT(3427927.825 5793243.775)
3 | 5 | 254 | POINT(3427927.875 5793243.775)
4 | 5 | 254 | POINT(3427927.925 5793243.775)
5 | 5 | 254 | POINT(3427927.975 5793243.775)
See Also
RT_ST_DumpAsPolygons, RT_ST_PixelAsPolygon, RT_ST_PixelAsPolygons, RT_ST_PixelAsPoint, RT_ST_PixelAsPoints, RT_ST_PixelAsCentroid
ST_Value
Returns the value of a given band in a given columnx, rowy pixel or at a particular geometric point. Band numbers start at 1 and assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster.
Synopsis
double precision ST_Value(raster rast, geometry pt, boolean exclude_nodata_value=true)
double precision ST_Value(raster rast, integer band, geometry pt, boolean exclude_nodata_value=true, text resample='nearest')
double precision ST_Value(raster rast, integer x, integer y, boolean exclude_nodata_value=true)
double precision ST_Value(raster rast, integer band, integer x, integer y, boolean exclude_nodata_value=true)
Description
Returns the value of a given band in a given columnx, rowy pixel or at a given geometry point. Band numbers start at 1 and band is assumed to be 1 if not specified.
If exclude_nodata_value is set to true, then only non nodata pixels are considered. If exclude_nodata_value is set to false, then all pixels are considered.
The allowed values of the resample parameter are "nearest" which performs the default nearest-neighbor resampling, and "bilinear" which performs a bilinear interpolation to estimate the value between pixel centers.
Enhanced: 3.2.0 resample optional argument was added.
Enhanced: 2.0.0 exclude_nodata_value optional argument was added.
Examples
-- get raster values at particular postgis geometry points
-- the srid of your geometry should be same as for your raster
SELECT rid, ST_Value(rast, foo.pt_geom) As b1pval, ST_Value(rast, 2, foo.pt_geom) As b2pval
FROM dummy_rast CROSS JOIN (SELECT ST_SetSRID(ST_Point(3427927.77, 5793243.76), 0) As pt_geom) As foo
WHERE rid=2;
rid | b1pval | b2pval
-----+--------+--------
2 | 252 | 79
-- general fictitious example using a real table
SELECT rid, ST_Value(rast, 3, sometable.geom) As b3pval
FROM sometable
WHERE ST_Intersects(rast,sometable.geom);
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
--- 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
:
:
--- 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_ScaleX(rast)*x,
ST_UpperLeftY(rast) + ST_ScaleY(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
:
--- 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_ScaleX(rast),
ST_UpperLeftY(rast) + ST_ScaleY(rast), 0
), ST_ScaleX(rast)*x, ST_ScaleY(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)))
--- 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_ScaleX(rast)*2,
ST_UpperLeftY(rast) + ST_ScaleY(rast)*2, 0
), ST_ScaleX(rast)*x, ST_ScaleY(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)))
See Also
RT_ST_SetValue, RT_ST_DumpAsPolygons, RT_ST_NumBands, RT_ST_PixelAsPolygon, RT_ST_ScaleX, RT_ST_ScaleY, RT_ST_UpperLeftX, RT_ST_UpperLeftY, RT_ST_SRID, ST_AsText, ST_Point, ST_MakeEnvelope, ST_Intersects, ST_Intersection
ST_NearestValue
Returns the nearest non-NODATA value of a given band's pixel specified by a columnx and rowy or a geometric point expressed in the same spatial reference coordinate system as the raster.
Synopsis
double precision ST_NearestValue(raster rast, integer bandnum, geometry pt, boolean exclude_nodata_value=true)
double precision ST_NearestValue(raster rast, geometry pt, boolean exclude_nodata_value=true)
double precision ST_NearestValue(raster rast, integer bandnum, integer columnx, integer rowy, boolean exclude_nodata_value=true)
double precision ST_NearestValue(raster rast, integer columnx, integer rowy, boolean exclude_nodata_value=true)
Description
Returns the nearest non-NODATA value of a given band in a given columnx, rowy pixel or at a specific geometric point. If the columnx, rowy pixel or the pixel at the specified geometric point is NODATA, the function will find the nearest pixel to the columnx, rowy pixel or geometric point whose value is not NODATA.
Band numbers start at 1 and bandnum is assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster.
Availability: 2.1.0
Note
ST_NearestValue is a drop-in replacement for ST_Value.
Examples
-- pixel 2x2 has value
SELECT
ST_Value(rast, 2, 2) AS value,
ST_NearestValue(rast, 2, 2) AS nearestvalue
FROM (
SELECT
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_AddBand(
ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0),
'8BUI'::text, 1, 0
),
1, 1, 0.
),
2, 3, 0.
),
3, 5, 0.
),
4, 2, 0.
),
5, 4, 0.
) AS rast
) AS foo
value | nearestvalue
-------+--------------
1 | 1
-- pixel 2x3 is NODATA
SELECT
ST_Value(rast, 2, 3) AS value,
ST_NearestValue(rast, 2, 3) AS nearestvalue
FROM (
SELECT
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_AddBand(
ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0),
'8BUI'::text, 1, 0
),
1, 1, 0.
),
2, 3, 0.
),
3, 5, 0.
),
4, 2, 0.
),
5, 4, 0.
) AS rast
) AS foo
value | nearestvalue
-------+--------------
| 1
See Also
RT_ST_Neighborhood, RT_ST_Value
ST_SetZ
Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the Z dimension using the requested resample algorithm.
Synopsis
geometry ST_SetZ(raster rast, geometry geom, text resample=nearest, integer band=1)
Description
Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the Z dimensions using the requested resample algorithm.
The resample parameter can be set to "nearest" to copy the values from the cell each vertex falls within, or "bilinear" to use bilinear interpolation to calculate a value that takes neighboring cells into account also.
Availability: 3.2.0
Examples
--
-- 2x2 test raster with values
--
-- 10 50
-- 40 20
--
WITH test_raster AS (
SELECT
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(width => 2, height => 2,
upperleftx => 0, upperlefty => 2,
scalex => 1.0, scaley => -1.0,
skewx => 0, skewy => 0, srid => 4326),
index => 1, pixeltype => '16BSI',
initialvalue => 0,
nodataval => -999),
1,1,1,
newvalueset =>ARRAY[ARRAY[10.0::float8, 50.0::float8], ARRAY[40.0::float8, 20.0::float8]]) AS rast
)
SELECT
ST_AsText(
ST_SetZ(
rast,
band => 1,
geom => 'SRID=4326;LINESTRING(1.0 1.9, 1.0 0.2)'::geometry,
resample => 'bilinear'
))
FROM test_raster
st_astext
----------------------------------
LINESTRING Z (1 1.9 38,1 0.2 27)
See Also
ST_SetM
Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the M dimension using the requested resample algorithm.
Synopsis
geometry ST_SetM(raster rast, geometry geom, text resample=nearest, integer band=1)
Description
Returns a geometry with the same X/Y coordinates as the input geometry, and values from the raster copied into the M dimensions using the requested resample algorithm.
The resample parameter can be set to "nearest" to copy the values from the cell each vertex falls within, or "bilinear" to use bilinear interpolation to calculate a value that takes neighboring cells into account also.
Availability: 3.2.0
Examples
--
-- 2x2 test raster with values
--
-- 10 50
-- 40 20
--
WITH test_raster AS (
SELECT
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(width => 2, height => 2,
upperleftx => 0, upperlefty => 2,
scalex => 1.0, scaley => -1.0,
skewx => 0, skewy => 0, srid => 4326),
index => 1, pixeltype => '16BSI',
initialvalue => 0,
nodataval => -999),
1,1,1,
newvalueset =>ARRAY[ARRAY[10.0::float8, 50.0::float8], ARRAY[40.0::float8, 20.0::float8]]) AS rast
)
SELECT
ST_AsText(
ST_SetM(
rast,
band => 1,
geom => 'SRID=4326;LINESTRING(1.0 1.9, 1.0 0.2)'::geometry,
resample => 'bilinear'
))
FROM test_raster
st_astext
----------------------------------
LINESTRING M (1 1.9 38,1 0.2 27)
See Also
ST_Neighborhood
Returns a 2-D double precision array of the non-NODATA values around a given band's pixel specified by either a columnX and rowY or a geometric point expressed in the same spatial reference coordinate system as the raster.
Synopsis
double precision[][] ST_Neighborhood(raster rast, integer bandnum, integer columnX, integer rowY, integer distanceX, integer distanceY, boolean exclude_nodata_value=true)
double precision[][] ST_Neighborhood(raster rast, integer columnX, integer rowY, integer distanceX, integer distanceY, boolean exclude_nodata_value=true)
double precision[][] ST_Neighborhood(raster rast, integer bandnum, geometry pt, integer distanceX, integer distanceY, boolean exclude_nodata_value=true)
double precision[][] ST_Neighborhood(raster rast, geometry pt, integer distanceX, integer distanceY, boolean exclude_nodata_value=true)
Description
Returns a 2-D double precision array of the non-NODATA values around a given band's pixel specified by either a columnX and rowY or a geometric point expressed in the same spatial reference coordinate system as the raster. The distanceX and distanceY parameters define the number of pixels around the specified pixel in the X and Y axes, e.g. I want all values within 3 pixel distance along the X axis and 2 pixel distance along the Y axis around my pixel of interest. The center value of the 2-D array will be the value at the pixel specified by the columnX and rowY or the geometric point.
Band numbers start at 1 and bandnum is assumed to be 1 if not specified. If exclude_nodata_value is set to false, then all pixels include nodata pixels are considered to intersect and return value. If exclude_nodata_value is not passed in then reads it from metadata of raster.
Note
The number of elements along each axis of the returning 2-D array is 2 * (distanceX|distanceY) + 1. So for a distanceX and distanceY of 1, the returning array will be 3x3.
Note
The 2-D array output can be passed to any of the raster processing builtin functions, e.g. ST_Min4ma, ST_Sum4ma, ST_Mean4ma.
Availability: 2.1.0
Examples
-- pixel 2x2 has value
SELECT
ST_Neighborhood(rast, 2, 2, 1, 1)
FROM (
SELECT
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0),
'8BUI'::text, 1, 0
),
1, 1, 1, ARRAY[
[0, 1, 1, 1, 1],
[1, 1, 1, 0, 1],
[1, 0, 1, 1, 1],
[1, 1, 1, 1, 0],
[1, 1, 0, 1, 1]
]::double precision[],
1
) AS rast
) AS foo
st_neighborhood
---------------------------------
{{NULL,1,1},{1,1,1},{1,NULL,1}}
-- pixel 2x3 is NODATA
SELECT
ST_Neighborhood(rast, 2, 3, 1, 1)
FROM (
SELECT
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0),
'8BUI'::text, 1, 0
),
1, 1, 1, ARRAY[
[0, 1, 1, 1, 1],
[1, 1, 1, 0, 1],
[1, 0, 1, 1, 1],
[1, 1, 1, 1, 0],
[1, 1, 0, 1, 1]
]::double precision[],
1
) AS rast
) AS foo
st_neighborhood
------------------------------
{{1,1,1},{1,NULL,1},{1,1,1}}
-- pixel 3x3 has value
-- exclude_nodata_value = FALSE
SELECT
ST_Neighborhood(rast, 3, 3, 1, 1, false)
FROM ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0),
'8BUI'::text, 1, 0
),
1, 1, 1, ARRAY[
[0, 1, 1, 1, 1],
[1, 1, 1, 0, 1],
[1, 0, 1, 1, 1],
[1, 1, 1, 1, 0],
[1, 1, 0, 1, 1]
]::double precision[],
1
) AS rast
st_neighborhood
---------------------------
{{1,1,0},{0,1,1},{1,1,1}}
See Also
RT_ST_NearestValue, RT_ST_Min4ma, RT_ST_Max4ma, RT_ST_Sum4ma, RT_ST_Mean4ma, RT_ST_Range4ma, RT_ST_Distinct4ma, RT_ST_StdDev4ma
ST_SetValue
Returns modified raster resulting from setting the value of a given band in a given columnx, rowy pixel or the pixels that intersect a particular geometry. Band numbers start at 1 and assumed to be 1 if not specified.
Synopsis
raster ST_SetValue(raster rast, integer bandnum, geometry geom, double precision newvalue)
raster ST_SetValue(raster rast, geometry geom, double precision newvalue)
raster ST_SetValue(raster rast, integer bandnum, integer columnx, integer rowy, double precision newvalue)
raster ST_SetValue(raster rast, integer columnx, integer rowy, double precision newvalue)
Description
Returns modified raster resulting from setting the specified pixels' values to new value for the designated band given the raster's row and column or a geometry. If no band is specified, then band 1 is assumed.
Enhanced: 2.1.0 Geometry variant of ST_SetValue() now supports any geometry type, not just point. The geometry variant is a wrapper around the geomval[] variant of ST_SetValues()
Examples
-- Geometry example
SELECT (foo.geomval).val, ST_AsText(ST_Union((foo.geomval).geom))
FROM (SELECT ST_DumpAsPolygons(
ST_SetValue(rast,1,
ST_Point(3427927.75, 5793243.95),
50)
) As geomval
FROM dummy_rast
where rid = 2) As foo
WHERE (foo.geomval).val < 250
GROUP BY (foo.geomval).val;
val | st_astext
-----+-------------------------------------------------------------------
50 | POLYGON((3427927.75 5793244,3427927.75 5793243.95,3427927.8 579324 ...
249 | POLYGON((3427927.95 5793243.95,3427927.95 5793243.85,3427928 57932 ...
-- Store the changed raster --
UPDATE dummy_rast SET rast = ST_SetValue(rast,1, ST_Point(3427927.75, 5793243.95),100)
WHERE rid = 2 ;
See Also
RT_ST_Value, RT_ST_DumpAsPolygons
ST_SetValues
Returns modified raster resulting from setting the values of a given band.
Synopsis
raster ST_SetValues(raster rast, integer nband, integer columnx, integer rowy, double precision[][] newvalueset, boolean[][] noset=NULL, boolean keepnodata=FALSE)
raster ST_SetValues(raster rast, integer nband, integer columnx, integer rowy, double precision[][] newvalueset, double precision nosetvalue, boolean keepnodata=FALSE)
raster ST_SetValues(raster rast, integer nband, integer columnx, integer rowy, integer width, integer height, double precision newvalue, boolean keepnodata=FALSE)
raster ST_SetValues(raster rast, integer columnx, integer rowy, integer width, integer height, double precision newvalue, boolean keepnodata=FALSE)
raster ST_SetValues(raster rast, integer nband, geomval[] geomvalset, boolean keepnodata=FALSE)
Description
Returns modified raster resulting from setting specified pixels to new value(s) for the designated band. columnx and rowy are 1-indexed.
If keepnodata is TRUE, those pixels whose values are NODATA will not be set with the corresponding value in newvalueset.
For Variant 1, the specific pixels to be set are determined by the columnx, rowy pixel coordinates and the dimensions of the newvalueset array. noset can be used to prevent pixels with values present in newvalueset from being set (due to PostgreSQL not permitting ragged/jagged arrays). See example Variant 1.
Variant 2 is like Variant 1 but with a simple double precision nosetvalue instead of a boolean noset array. Elements in newvalueset with the nosetvalue value with be skipped. See example Variant 2.
For Variant 3, the specific pixels to be set are determined by the columnx, rowy pixel coordinates, width and height. See example Variant 3.
Variant 4 is the same as Variant 3 with the exception that it assumes that the first band's pixels of rast will be set.
For Variant 5, an array of geomval is used to determine the specific pixels to be set. If all the geometries in the array are of type POINT or MULTIPOINT, the function uses a shortcut where the longitude and latitude of each point is used to set a pixel directly. Otherwise, the geometries are converted to rasters and then iterated through in one pass. See example Variant 5.
Availability: 2.1.0
Examples: Variant 1
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 1 | 1 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 2, 2, ARRAY[[9, 9], [9, 9]]::double precision[][]
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 1
1 | 2 | 1
1 | 3 | 1
2 | 1 | 1
2 | 2 | 9
2 | 3 | 9
3 | 1 | 1
3 | 2 | 9
3 | 3 | 9
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 9 | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 9 | | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 9 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 1, 1, ARRAY[[9, 9, 9], [9, NULL, 9], [9, 9, 9]]::double precision[][]
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 9
1 | 2 | 9
1 | 3 | 9
2 | 1 | 9
2 | 2 |
2 | 3 | 9
3 | 1 | 9
3 | 2 | 9
3 | 3 | 9
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 9 | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 1 | | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 9 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 1, 1,
ARRAY[[9, 9, 9], [9, NULL, 9], [9, 9, 9]]::double precision[][],
ARRAY[[false], [true]]::boolean[][]
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 9
1 | 2 | 1
1 | 3 | 9
2 | 1 | 9
2 | 2 |
2 | 3 | 9
3 | 1 | 9
3 | 2 | 9
3 | 3 | 9
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| | 1 | 1 | | | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 1 | | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 9 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_SetValue(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 1, 1, NULL
),
1, 1, 1,
ARRAY[[9, 9, 9], [9, NULL, 9], [9, 9, 9]]::double precision[][],
ARRAY[[false], [true]]::boolean[][],
TRUE
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 |
1 | 2 | 1
1 | 3 | 9
2 | 1 | 9
2 | 2 |
2 | 3 | 9
3 | 1 | 9
3 | 2 | 9
3 | 3 | 9
Examples: Variant 2
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 1 | 1 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 1, 1, ARRAY[[-1, -1, -1], [-1, 9, 9], [-1, 9, 9]]::double precision[][], -1
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 1
1 | 2 | 1
1 | 3 | 1
2 | 1 | 1
2 | 2 | 9
2 | 3 | 9
3 | 1 | 1
3 | 2 | 9
3 | 3 | 9
/*
This example is like the previous one. Instead of nosetvalue = -1, nosetvalue = NULL
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 1 | 1 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 1, 1, ARRAY[[NULL, NULL, NULL], [NULL, 9, 9], [NULL, 9, 9]]::double precision[][], NULL::double precision
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 1
1 | 2 | 1
1 | 3 | 1
2 | 1 | 1
2 | 2 | 9
2 | 3 | 9
3 | 1 | 1
3 | 2 | 9
3 | 3 | 9
Examples: Variant 3
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 1 | 1 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | => | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 2, 2, 2, 2, 9
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 1
1 | 2 | 1
1 | 3 | 1
2 | 1 | 1
2 | 2 | 9
2 | 3 | 9
3 | 1 | 1
3 | 2 | 9
3 | 3 | 9
/*
The ST_SetValues() does the following...
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 1 | 1 |
+ - + - + - + + - + - + - +
| 1 | | 1 | => | 1 | | 9 |
+ - + - + - + + - + - + - +
| 1 | 1 | 1 | | 1 | 9 | 9 |
+ - + - + - + + - + - + - +
*/
SELECT
(poly).x,
(poly).y,
(poly).val
FROM (
SELECT
ST_PixelAsPolygons(
ST_SetValues(
ST_SetValue(
ST_AddBand(
ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0),
1, '8BUI', 1, 0
),
1, 2, 2, NULL
),
1, 2, 2, 2, 2, 9, TRUE
)
) AS poly
) foo
ORDER BY 1, 2;
x | y | val
---+---+-----
1 | 1 | 1
1 | 2 | 1
1 | 3 | 1
2 | 1 | 1
2 | 2 |
2 | 3 | 9
3 | 1 | 1
3 | 2 | 9
3 | 3 | 9
Examples: Variant 5
WITH foo AS (
SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0) AS rast
), bar AS (
SELECT 1 AS gid, 'SRID=0;POINT(2.5 -2.5)'::geometry geom UNION ALL
SELECT 2 AS gid, 'SRID=0;POLYGON((1 -1, 4 -1, 4 -4, 1 -4, 1 -1))'::geometry geom UNION ALL
SELECT 3 AS gid, 'SRID=0;POLYGON((0 0, 5 0, 5 -1, 1 -1, 1 -4, 0 -4, 0 0))'::geometry geom UNION ALL
SELECT 4 AS gid, 'SRID=0;MULTIPOINT(0 0, 4 4, 4 -4)'::geometry
)
SELECT
rid, gid, ST_DumpValues(ST_SetValue(rast, 1, geom, gid))
FROM foo t1
CROSS JOIN bar t2
ORDER BY rid, gid;
rid | gid | st_dumpvalues
-----+-----+---------------------------------------------------------------------------------------------------------------------------------------------
1 | 1 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,1,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL}}")
1 | 2 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,NULL,NULL,NULL,NULL}}")
1 | 3 | (1,"{{3,3,3,3,3},{3,NULL,NULL,NULL,NULL},{3,NULL,NULL,NULL,NULL},{3,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL}}")
1 | 4 | (1,"{{4,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,NULL},{NULL,NULL,NULL,NULL,4}}")
(4 rows)
The following shows that geomvals later in the array can overwrite prior geomvals
WITH foo AS (
SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0) AS rast
), bar AS (
SELECT 1 AS gid, 'SRID=0;POINT(2.5 -2.5)'::geometry geom UNION ALL
SELECT 2 AS gid, 'SRID=0;POLYGON((1 -1, 4 -1, 4 -4, 1 -4, 1 -1))'::geometry geom UNION ALL
SELECT 3 AS gid, 'SRID=0;POLYGON((0 0, 5 0, 5 -1, 1 -1, 1 -4, 0 -4, 0 0))'::geometry geom UNION ALL
SELECT 4 AS gid, 'SRID=0;MULTIPOINT(0 0, 4 4, 4 -4)'::geometry
)
SELECT
t1.rid, t2.gid, t3.gid, ST_DumpValues(ST_SetValues(rast, 1, ARRAY[ROW(t2.geom, t2.gid), ROW(t3.geom, t3.gid)]::geomval[]))
FROM foo t1
CROSS JOIN bar t2
CROSS JOIN bar t3
WHERE t2.gid = 1
AND t3.gid = 2
ORDER BY t1.rid, t2.gid, t3.gid;
rid | gid | gid | st_dumpvalues
-----+-----+-----+---------------------------------------------------------------------------------------------------------------------
1 | 1 | 2 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,2,2,2,NULL},{NULL,NULL,NULL,NULL,NULL}}")
(1 row)
This example is the opposite of the prior example
WITH foo AS (
SELECT 1 AS rid, ST_AddBand(ST_MakeEmptyRaster(5, 5, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 0, 0) AS rast
), bar AS (
SELECT 1 AS gid, 'SRID=0;POINT(2.5 -2.5)'::geometry geom UNION ALL
SELECT 2 AS gid, 'SRID=0;POLYGON((1 -1, 4 -1, 4 -4, 1 -4, 1 -1))'::geometry geom UNION ALL
SELECT 3 AS gid, 'SRID=0;POLYGON((0 0, 5 0, 5 -1, 1 -1, 1 -4, 0 -4, 0 0))'::geometry geom UNION ALL
SELECT 4 AS gid, 'SRID=0;MULTIPOINT(0 0, 4 4, 4 -4)'::geometry
)
SELECT
t1.rid, t2.gid, t3.gid, ST_DumpValues(ST_SetValues(rast, 1, ARRAY[ROW(t2.geom, t2.gid), ROW(t3.geom, t3.gid)]::geomval[]))
FROM foo t1
CROSS JOIN bar t2
CROSS JOIN bar t3
WHERE t2.gid = 2
AND t3.gid = 1
ORDER BY t1.rid, t2.gid, t3.gid;
rid | gid | gid | st_dumpvalues
-----+-----+-----+---------------------------------------------------------------------------------------------------------------------
1 | 2 | 1 | (1,"{{NULL,NULL,NULL,NULL,NULL},{NULL,2,2,2,NULL},{NULL,2,1,2,NULL},{NULL,2,2,2,NULL},{NULL,NULL,NULL,NULL,NULL}}")
(1 row)
See Also
RT_ST_Value, RT_ST_SetValue, RT_ST_PixelAsPolygons
ST_DumpValues
Get the values of the specified band as a 2-dimension array.
Synopsis
setof record ST_DumpValues(raster rast, integer[] nband=NULL, boolean exclude_nodata_value=true)
double precision[][] ST_DumpValues(raster rast, integer nband, boolean exclude_nodata_value=true)
Description
Get the values of the specified band as a 2-dimension array (first index is row, second is column). If nband is NULL or not provided, all raster bands are processed.
Availability: 2.1.0
Examples
WITH foo AS (
SELECT ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI'::text, 1, 0), 2, '32BF'::text, 3, -9999), 3, '16BSI', 0, 0) AS rast
)
SELECT
(ST_DumpValues(rast)).*
FROM foo;
nband | valarray
-------+------------------------------------------------------
1 | {{1,1,1},{1,1,1},{1,1,1}}
2 | {{3,3,3},{3,3,3},{3,3,3}}
3 | {{NULL,NULL,NULL},{NULL,NULL,NULL},{NULL,NULL,NULL}}
(3 rows)
WITH foo AS (
SELECT ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI'::text, 1, 0), 2, '32BF'::text, 3, -9999), 3, '16BSI', 0, 0) AS rast
)
SELECT
(ST_DumpValues(rast, ARRAY[3, 1])).*
FROM foo;
nband | valarray
-------+------------------------------------------------------
3 | {{NULL,NULL,NULL},{NULL,NULL,NULL},{NULL,NULL,NULL}}
1 | {{1,1,1},{1,1,1},{1,1,1}}
(2 rows)
WITH foo AS (
SELECT ST_SetValue(ST_AddBand(ST_MakeEmptyRaster(3, 3, 0, 0, 1, -1, 0, 0, 0), 1, '8BUI', 1, 0), 1, 2, 5) AS rast
)
SELECT
(ST_DumpValues(rast, 1))[2][1]
FROM foo;
st_dumpvalues
---------------
5
(1 row)
See Also
RT_ST_Value, RT_ST_SetValue, RT_ST_SetValues
ST_PixelOfValue
Get the columnx, rowy coordinates of the pixel whose value equals the search value.
Synopsis
setof record ST_PixelOfValue(raster rast, integer nband, double precision[] search, boolean exclude_nodata_value=true)
setof record ST_PixelOfValue(raster rast, double precision[] search, boolean exclude_nodata_value=true)
setof record ST_PixelOfValue(raster rast, integer nband, double precision search, boolean exclude_nodata_value=true)
setof record ST_PixelOfValue(raster rast, double precision search, boolean exclude_nodata_value=true)
Description
Get the columnx, rowy coordinates of the pixel whose value equals the search value. If no band is specified, then band 1 is assumed.
Availability: 2.1.0
Examples
SELECT
(pixels).*
FROM (
SELECT
ST_PixelOfValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_SetValue(
ST_AddBand(
ST_MakeEmptyRaster(5, 5, -2, 2, 1, -1, 0, 0, 0),
'8BUI'::text, 1, 0
),
1, 1, 0
),
2, 3, 0
),
3, 5, 0
),
4, 2, 0
),
5, 4, 255
)
, 1, ARRAY[1, 255]) AS pixels
) AS foo
val | x | y
-----+---+---
1 | 1 | 2
1 | 1 | 3
1 | 1 | 4
1 | 1 | 5
1 | 2 | 1
1 | 2 | 2
1 | 2 | 4
1 | 2 | 5
1 | 3 | 1
1 | 3 | 2
1 | 3 | 3
1 | 3 | 4
1 | 4 | 1
1 | 4 | 3
1 | 4 | 4
1 | 4 | 5
1 | 5 | 1
1 | 5 | 2
1 | 5 | 3
255 | 5 | 4
1 | 5 | 5