gdal raster mosaic/stack: add a --resolution=same mode, and default t…

…o it

apps/gdalalg_raster_mosaic.cpp

@@ -46,15 +46,18 @@ GDALRasterMosaicAlgorithm::GDALRasterMosaicAlgorithm()
     AddArg("band", 'b', _("Specify input band(s) number."), &m_bands);
     AddOverwriteArg(&m_overwrite);
     {
-        auto &arg = AddArg("resolution", 0,
-                           _("Target resolution (in destination CRS units)"),
-                           &m_resolution)
-                        .SetMetaVar("<xres>,<yres>|average|highest|lowest");
+        auto &arg =
+            AddArg("resolution", 0,
+                   _("Target resolution (in destination CRS units)"),
+                   &m_resolution)
+                .SetDefault("same")
+                .SetMetaVar("<xres>,<yres>|same|average|highest|lowest");
         arg.AddValidationAction(
             [this, &arg]()
             {
                 const std::string val = arg.Get<std::string>();
-                if (val != "average" && val != "highest" && val != "lowest")
+                if (val != "average" && val != "highest" && val != "lowest" &&
+                    val != "same")
                 {
                     const auto aosTokens =
                         CPLStringList(CSLTokenizeString2(val.c_str(), ",", 0));
@@ -66,8 +69,8 @@ GDALRasterMosaicAlgorithm::GDALRasterMosaicAlgorithm()
                     {
                         ReportError(CE_Failure, CPLE_AppDefined,
                                     "resolution: two comma separated positive "
-                                    "values should be provided, or 'average', "
-                                    "'highest' or 'lowest'");
+                                    "values should be provided, or 'same', "
+                                    "'average', 'highest' or 'lowest'");
                         return false;
                     }
                 }
@@ -190,7 +193,12 @@ bool GDALRasterMosaicAlgorithm::RunImpl(GDALProgressFunc pfnProgress,
     aosOptions.push_back("-program_name");
     aosOptions.push_back("gdal raster mosaic");
 
-    if (!m_resolution.empty())
+    if (m_resolution.empty())
+    {
+        aosOptions.push_back("-resolution");
+        aosOptions.push_back("same");
+    }
+    else
     {
         const auto aosTokens =
             CPLStringList(CSLTokenizeString2(m_resolution.c_str(), ",", 0));

apps/gdalalg_raster_stack.cpp

@@ -46,15 +46,18 @@ GDALRasterStackAlgorithm::GDALRasterStackAlgorithm()
     AddArg("band", 'b', _("Specify input band(s) number."), &m_bands);
     AddOverwriteArg(&m_overwrite);
     {
-        auto &arg = AddArg("resolution", 0,
-                           _("Target resolution (in destination CRS units)"),
-                           &m_resolution)
-                        .SetMetaVar("<xres>,<yres>|average|highest|lowest");
+        auto &arg =
+            AddArg("resolution", 0,
+                   _("Target resolution (in destination CRS units)"),
+                   &m_resolution)
+                .SetDefault("same")
+                .SetMetaVar("<xres>,<yres>|same|average|highest|lowest");
         arg.AddValidationAction(
             [this, &arg]()
             {
                 const std::string val = arg.Get<std::string>();
-                if (val != "average" && val != "highest" && val != "lowest")
+                if (val != "average" && val != "highest" && val != "lowest" &&
+                    val != "same")
                 {
                     const auto aosTokens =
                         CPLStringList(CSLTokenizeString2(val.c_str(), ",", 0));
@@ -66,8 +69,8 @@ GDALRasterStackAlgorithm::GDALRasterStackAlgorithm()
                     {
                         ReportError(CE_Failure, CPLE_AppDefined,
                                     "resolution: two comma separated positive "
-                                    "values should be provided, or 'average', "
-                                    "'highest' or 'lowest'");
+                                    "values should be provided, or 'same', "
+                                    "'average', 'highest' or 'lowest'");
                         return false;
                     }
                 }
@@ -188,7 +191,12 @@ bool GDALRasterStackAlgorithm::RunImpl(GDALProgressFunc pfnProgress,
 
     aosOptions.push_back("-separate");
 
-    if (!m_resolution.empty())
+    if (m_resolution.empty())
+    {
+        aosOptions.push_back("-resolution");
+        aosOptions.push_back("same");
+    }
+    else
     {
         const auto aosTokens =
             CPLStringList(CSLTokenizeString2(m_resolution.c_str(), ",", 0));
@@ -204,6 +212,7 @@ bool GDALRasterStackAlgorithm::RunImpl(GDALProgressFunc pfnProgress,
             aosOptions.push_back(m_resolution);
         }
     }
+
     if (!m_bbox.empty())
     {
         aosOptions.push_back("-te");

autotest/utilities/test_gdalalg_raster_mosaic.py

@@ -115,6 +115,7 @@ def test_gdalalg_raster_mosaic_resolution_average():
 
     alg = get_mosaic_alg()
     alg.GetArg("input").Set([src1_ds, src2_ds])
+    alg.GetArg("resolution").Set("average")
     alg.GetArg("output").Set("")
     assert alg.Run()
     ds = alg.GetArg("output").Get().GetDataset()
@@ -196,24 +197,41 @@ def test_gdalalg_raster_mosaic_target_aligned_pixels():
     assert ds.GetGeoTransform() == pytest.approx((1.8, 0.3, 0.0, 49.2, 0.0, -0.6))
 
 
+def test_gdalalg_raster_mosaic_resolution_same_default():
+
+    src1_ds = gdal.GetDriverByName("MEM").Create("", 1, 1)
+    src1_ds.SetGeoTransform([2, 1, 0, 49, 0, -1])
+    src2_ds = gdal.GetDriverByName("MEM").Create("", 2, 2)
+    src2_ds.SetGeoTransform([3, 0.5, 0, 49, 0, -0.5])
+
+    alg = get_mosaic_alg()
+    alg.GetArg("input").Set([src1_ds, src2_ds])
+    alg.GetArg("output").Set("")
+    with pytest.raises(
+        Exception,
+        match="whereas previous sources have resolution",
+    ):
+        assert alg.Run()
+
+
 def test_gdalalg_raster_mosaic_resolution_invalid():
 
     alg = get_mosaic_alg()
     with pytest.raises(
         Exception,
-        match="resolution: two comma separated positive values should be provided, or 'average', 'highest' or 'lowest'",
+        match="resolution: two comma separated positive values should be provided, or 'same', 'average', 'highest' or 'lowest'",
     ):
         alg.GetArg("resolution").Set("invalid")
 
     with pytest.raises(
         Exception,
-        match="resolution: two comma separated positive values should be provided, or 'average', 'highest' or 'lowest'",
+        match="resolution: two comma separated positive values should be provided, or 'same', 'average', 'highest' or 'lowest'",
     ):
         alg.GetArg("resolution").Set("0.5")
 
     with pytest.raises(
         Exception,
-        match="resolution: two comma separated positive values should be provided, or 'average', 'highest' or 'lowest'",
+        match="resolution: two comma separated positive values should be provided, or 'same', 'average', 'highest' or 'lowest'",
     ):
         alg.GetArg("resolution").Set("-0.5,-0.5")
 

doc/source/programs/gdal_raster_mosaic.rst

@@ -22,30 +22,29 @@ Synopsis
     Build a mosaic, either virtual (VRT) or materialized
 
     Positional arguments:
-      -i, --input <INPUTS>                                 Input raster datasets (or specify a @<filename> to point to a file containing filenames) [1.. values]
-      -o, --output <OUTPUT>                                Output raster dataset (created by algorithm) [required]
+      -i, --input <INPUTS>                                     Input raster datasets (or specify a @<filename> to point to a file containing filenames) [1.. values]
+      -o, --output <OUTPUT>                                    Output raster dataset (created by algorithm) [required]
 
     Common Options:
-      -h, --help                                           Display help message and exit
-      --version                                            Display GDAL version and exit
-      --json-usage                                         Display usage as JSON document and exit
-      --drivers                                            Display driver list as JSON document and exit
-      --config <KEY>=<VALUE>                               Configuration option [may be repeated]
-      --progress                                           Display progress bar
+      -h, --help                                               Display help message and exit
+      --version                                                Display GDAL version and exit
+      --json-usage                                             Display usage as JSON document and exit
+      --drivers                                                Display driver list as JSON document and exit
+      --config <KEY>=<VALUE>                                   Configuration option [may be repeated]
+      --progress                                               Display progress bar
 
     Options:
-      -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format
-      --co, --creation-option <KEY>=<VALUE>                Creation option [may be repeated]
-      -b, --band <BAND>                                    Specify input band(s) number. [may be repeated]
-      --overwrite                                          Whether overwriting existing output is allowed
-      --resolution <xres>,<yres>|average|highest|lowest>   Target resolution (in destination CRS units)
-      --bbox <BBOX>                                        Target bounding box as xmin,ymin,xmax,ymax (in destination CRS units)
-      --target-aligned-pixels                              Round target extent to target resolution
-      --srcnodata <SRCNODATA>                              Set nodata values for input bands. [1.. values]
-      --dstnodata <VRTNODATA>                              Set nodata values at the destination band level. [1.. values]
-      --hidenodata                                         Makes the destination band not report the NoData.
-      --addalpha                                           Adds an alpha mask band to the destination when the source raster have none.
-
+      -f, --of, --format, --output-format <OUTPUT-FORMAT>      Output format
+      --co, --creation-option <KEY>=<VALUE>                    Creation option [may be repeated]
+      -b, --band <BAND>                                        Specify input band(s) number. [may be repeated]
+      --overwrite                                              Whether overwriting existing output is allowed
+      --resolution <xres>,<yres>|same|average|highest|lowest>  Target resolution (in destination CRS units) (default: same)
+      --bbox <BBOX>                                            Target bounding box as xmin,ymin,xmax,ymax (in destination CRS units)
+      --target-aligned-pixels                                  Round target extent to target resolution
+      --srcnodata <SRCNODATA>                                  Set nodata values for input bands. [1.. values]
+      --dstnodata <DSTNODATA>                                  Set nodata values at the destination band level. [1.. values]
+      --hidenodata                                             Makes the destination band not report the NoData.
+      --addalpha                                               Adds an alpha mask band to the destination when the source raster have none.
 
 
 Description
@@ -86,16 +85,18 @@ The following options are available:
     If input bands not set all bands will be added to the output.
     Multiple :option:`-b` switches may be used to select a set of input bands.
 
-.. option:: --resolution {<xres,yres>|highest|lowest|average}
+.. option:: --resolution {<xres,yres>|same|highest|lowest|average}
 
     In case the resolution of all input files is not the same, the :option:`--resolution` flag
     enables the user to control the way the output resolution is computed.
 
+    `same`, the default, checks that all source rasters have the same resolution and errors out when this is not the case.
+
     `highest` will pick the smallest values of pixel dimensions within the set of source rasters.
 
     `lowest` will pick the largest values of pixel dimensions within the set of source rasters.
 
-    `average` is the default and will compute an average of pixel dimensions within the set of source rasters.
+    `average` will compute an average of pixel dimensions within the set of source rasters.
 
     <xres>,<yres>. The values must be expressed in georeferenced units.
     Both must be positive values.

doc/source/programs/gdal_raster_stack.rst

@@ -23,29 +23,28 @@ Synopsis
     Combine together input bands into a multi-band output, either virtual (VRT) or materialized.
 
     Positional arguments:
-      -i, --input <INPUTS>                                 Input raster datasets (or specify a @<filename> to point to a file containing filenames) [1.. values]
-      -o, --output <OUTPUT>                                Output raster dataset (created by algorithm) [required]
+      -i, --input <INPUTS>                                     Input raster datasets (or specify a @<filename> to point to a file containing filenames) [1.. values]
+      -o, --output <OUTPUT>                                    Output raster dataset (created by algorithm) [required]
 
     Common Options:
-      -h, --help                                           Display help message and exit
-      --version                                            Display GDAL version and exit
-      --json-usage                                         Display usage as JSON document and exit
-      --drivers                                            Display driver list as JSON document and exit
-      --config <KEY>=<VALUE>                               Configuration option [may be repeated]
-      --progress                                           Display progress bar
+      -h, --help                                               Display help message and exit
+      --version                                                Display GDAL version and exit
+      --json-usage                                             Display usage as JSON document and exit
+      --drivers                                                Display driver list as JSON document and exit
+      --config <KEY>=<VALUE>                                   Configuration option [may be repeated]
+      --progress                                               Display progress bar
 
     Options:
-      -f, --of, --format, --output-format <OUTPUT-FORMAT>  Output format
-      --co, --creation-option <KEY>=<VALUE>                Creation option [may be repeated]
-      -b, --band <BAND>                                    Specify input band(s) number. [may be repeated]
-      --overwrite                                          Whether overwriting existing output is allowed
-      --resolution <xres>,<yres>|average|highest|lowest>   Target resolution (in destination CRS units)
-      --bbox <BBOX>                                        Target bounding box as xmin,ymin,xmax,ymax (in destination CRS units)
-      --target-aligned-pixels                              Round target extent to target resolution
-      --srcnodata <SRCNODATA>                              Set nodata values for input bands. [1.. values]
-      --dstnodata <VRTNODATA>                              Set nodata values at the destination band level. [1.. values]
-      --hidenodata                                         Makes the destination band not report the NoData.
-
+      -f, --of, --format, --output-format <OUTPUT-FORMAT>      Output format
+      --co, --creation-option <KEY>=<VALUE>                    Creation option [may be repeated]
+      -b, --band <BAND>                                        Specify input band(s) number. [may be repeated]
+      --overwrite                                              Whether overwriting existing output is allowed
+      --resolution <xres>,<yres>|same|average|highest|lowest>  Target resolution (in destination CRS units) (default: same)
+      --bbox <BBOX>                                            Target bounding box as xmin,ymin,xmax,ymax (in destination CRS units)
+      --target-aligned-pixels                                  Round target extent to target resolution
+      --srcnodata <SRCNODATA>                                  Set nodata values for input bands. [1.. values]
+      --dstnodata <DSTNODATA>                                  Set nodata values at the destination band level. [1.. values]
+      --hidenodata                                             Makes the destination band not report the NoData.
 
 
 Description
@@ -77,16 +76,18 @@ The following options are available:
     If input bands not set all bands will be added to the output.
     Multiple :option:`-b` switches may be used to select a set of input bands.
 
-.. option:: --resolution {<xres,yres>|highest|lowest|average}
+.. option:: --resolution {<xres,yres>|same|highest|lowest|average}
 
     In case the resolution of all input files is not the same, the :option:`--resolution` flag
     enables the user to control the way the output resolution is computed.
 
+    `same`, the default, checks that all source rasters have the same resolution and errors out when this is not the case.
+
     `highest` will pick the smallest values of pixel dimensions within the set of source rasters.
 
     `lowest` will pick the largest values of pixel dimensions within the set of source rasters.
 
-    `average` is the default and will compute an average of pixel dimensions within the set of source rasters.
+    `average` will compute an average of pixel dimensions within the set of source rasters.
 
     <xres>,<yres>. The values must be expressed in georeferenced units.
     Both must be positive values.