Filter selection enhancements

src/doc/imagebufalgo.tex

@@ -1818,7 +1818,8 @@ \section{Convolutions}
 
 Kernel names can be: \qkw{gaussian}, \qkw{sharp-gaussian}, \qkw{box},
 \qkw{triangle}, \qkw{mitchell}, \qkw{blackman-harris}, \qkw{b-spline},
-\qkw{catmull-rom}, \qkw{lanczos3}, \qkw{cubic}, \qkw{keys}, \qkw{simon},
+\qkw{catmull-rom}, \qkw{lanczos3} (synonym: \qkw{nuke-lanczos6}),
+\qkw{cubic}, \qkw{keys}, \qkw{simon},
 \qkw{rifman}, \qkw{disk}, \qkw{binomial}, \qkw{laplacian}. Note that
 \qkw{catmull-rom} and \qkw{lanczos3} are fixed-size kernels that don't
 scale with the width, and are therefore probably less useful in most

src/doc/oiiotool.tex

@@ -718,7 +718,7 @@ \section{\oiiotool commands: general and image information}
 
 \apiitem{\ce --help}
 Prints full usage information to the terminal, as well as information
-about image formats supported, known color spaces, OIIO build options
+about image formats supported, known color spaces, filters, OIIO build options
 and library dependencies.
 \apiend
 
@@ -1772,7 +1772,8 @@ \section{\oiiotool commands that make entirely new images}
 Kernel names can be: {\cf gaussian}, {\cf sharp-gaussian}, {\cf box},
 {\cf triangle}, {\cf blackman-harris}, {\cf mitchell}, {\cf b-spline},
 \qkw{cubic}, \qkw{keys}, \qkw{simon}, \qkw{rifman}, {\cf disk}.
-There are also {\cf catmull-rom} and {\cf lanczos3}, but
+There are also {\cf catmull-rom} and {\cf lanczos3} (and its synonym,
+{\cf nuke-lanczos6}), but
 they are fixed-size kernels that don't scale with the width, and are
 therefore probably less useful in most cases.
 

src/include/OpenImageIO/filter.h

@@ -86,6 +86,7 @@ class OIIO_API Filter1D {
     static int num_filters();
     /// Get the info for a particular index (0..num_filters()-1).
     static void get_filterdesc(int filternum, FilterDesc* filterdesc);
+    static const FilterDesc& get_filterdesc(int filternum);
 
 protected:
     float m_w;
@@ -143,6 +144,7 @@ class OIIO_API Filter2D {
     static int num_filters();
     /// Get the info for a particular index (0..num_filters()-1).
     static void get_filterdesc(int filternum, FilterDesc* filterdesc);
+    static const FilterDesc& get_filterdesc(int filternum);
 
 protected:
     float m_w, m_h;

src/libutil/filter.cpp

@@ -36,7 +36,9 @@
 //     - prman 16.0 txmake
 //
 // box: oiio, prman, katana, imagemagick match
-// lanczos3: oiio, katana, imagemagick match.  prman is far sharper (perhaps lanczos2?)
+// lanczos3: oiio, katana, imagemagick match.  prman is far sharper
+//   (perhaps lanczos2?). Note that Nuke calls this filter "lanczos6" (they
+//   measure full width).
 // sinc: oiio, prman match.  Katana is slighly softer. imagemagick is much softer
 // blackman harris:  all differ. In order of decreasing sharpness... imagemagick, oiio, prman
 // catrom: oiio, imagemagick, prman match
@@ -848,6 +850,7 @@ FilterDesc filter1d_list[] = {
     { "blackman-harris", 1,   3,    false,    true,     true },
     { "sinc",            1,   4,    false,    true,     true },
     { "lanczos3",        1,   6,    false,    true,     true },
+    { "nuke-lanczos6",   1,   6,    false,    true,     true },
     { "mitchell",        1,   4,    false,    true,     true },
     { "bspline",         1,   4,    false,    true,     true },
     { "cubic",           1,   4,    false,    true,     true },
@@ -864,11 +867,17 @@ Filter1D::num_filters()
     return sizeof(filter1d_list) / sizeof(filter1d_list[0]);
 }
 
+const FilterDesc&
+Filter1D::get_filterdesc(int filternum)
+{
+    ASSERT(filternum >= 0 && filternum < num_filters());
+    return filter1d_list[filternum];
+}
+
 void
 Filter1D::get_filterdesc(int filternum, FilterDesc* filterdesc)
 {
-    ASSERT(filternum >= 0 && filternum < num_filters());
-    *filterdesc = filter1d_list[filternum];
+    *filterdesc = get_filterdesc(filternum);
 }
 
 
@@ -894,7 +903,8 @@ Filter1D::create(string_view filtername, float width)
         return new FilterBlackmanHarris1D(width);
     if (filtername == "sinc")
         return new FilterSinc1D(width);
-    if (filtername == "lanczos3" || filtername == "lanczos")
+    if (filtername == "lanczos3" || filtername == "lanczos"
+        || filtername == "nuke-lanczos6")
         return new FilterLanczos3_1D(width);
     if (filtername == "mitchell")
         return new FilterMitchell1D(width);
@@ -933,6 +943,7 @@ static FilterDesc filter2d_list[] = {
     { "sinc",            2,   4,    false,    true,     true  },
     { "lanczos3",        2,   6,    false,    true,     true  },
     { "radial-lanczos3", 2,   6,    false,    true,     false },
+    { "nuke-lanczos6",   2,   6,    false,    true,     false },
     { "mitchell",        2,   4,    false,    true,     true  },
     { "bspline",         2,   4,    false,    true,     true  },
     { "disk",            2,   1,    false,    true,     false },
@@ -949,11 +960,17 @@ Filter2D::num_filters()
     return sizeof(filter2d_list) / sizeof(filter2d_list[0]);
 }
 
+const FilterDesc&
+Filter2D::get_filterdesc(int filternum)
+{
+    ASSERT(filternum >= 0 && filternum < num_filters());
+    return filter2d_list[filternum];
+}
+
 void
 Filter2D::get_filterdesc(int filternum, FilterDesc* filterdesc)
 {
-    ASSERT(filternum >= 0 && filternum < num_filters());
-    *filterdesc = filter2d_list[filternum];
+    *filterdesc = get_filterdesc(filternum);
 }
 
 
@@ -980,7 +997,8 @@ Filter2D::create(string_view filtername, float width, float height)
         return new FilterBlackmanHarris2D(width, height);
     if (filtername == "sinc")
         return new FilterSinc2D(width, height);
-    if (filtername == "lanczos3" || filtername == "lanczos")
+    if (filtername == "lanczos3" || filtername == "lanczos"
+        || filtername == "nuke-lanczos6")
         return new FilterLanczos3_2D(width, height);
     if (filtername == "radial-lanczos3" || filtername == "radial-lanczos")
         return new FilterRadialLanczos3_2D(width, height);

src/libutil/filter_test.cpp

@@ -60,8 +60,8 @@ getargs(int argc, char* argv[])
     ArgParse ap;
     // clang-format off
     ap.options(
-        "fmath_test\n" OIIO_INTRO_STRING "\n"
-        "Usage:  fmath_test [options]",
+        "filter_test\n" OIIO_INTRO_STRING "\n"
+        "Usage:  filter_test [options]",
         // "%*", parse_files, "",
         "--help", &help, "Print help message",
         "-v", &verbose, "Verbose mode",

src/oiiotool/oiiotool.cpp

@@ -5370,6 +5370,15 @@ print_help_end(const ArgParse& ap, std::ostream& out)
     }
     if (!ot.colorconfig.supportsOpenColorIO())
         out << "No OpenColorIO support was enabled at build time.\n";
+
+    std::vector<string_view> filternames;
+    for (int i = 0, e = Filter2D::num_filters(); i < e; ++i)
+        filternames.emplace_back(Filter2D::get_filterdesc(i).name);
+    out << Strutil::wordwrap("Filters available: "
+                                 + Strutil::join(filternames, ", "),
+                             columns, 4)
+        << "\n";
+
     std::string libs = OIIO::get_string_attribute("library_list");
     if (libs.size()) {
         std::vector<string_view> libvec;