LibRaw wavelet denoise options (#4028)

- ``raw:threshold``
     - float
     - Libraw parameter for noise reduction through wavelet denoising..
       The best threshold should be somewhere between 100 and 1000.

- ``raw:fbdd_noiserd`` 
    - int 
    - Controls FBDD noise reduction before demosaic. 0 - do not use FBDD
       noise reduction, 1 - light FBDD reduction, 2 (and more) - full FBDD reduction

---------

Signed-off-by: ssh4net <[email protected]>

src/doc/builtinplugins.rst

@@ -1926,8 +1926,17 @@ options are supported:
      - int
      - Set libraw user flip value : -1 ignored, other values are between [0; 8] with the same 
        definition than the Exif orientation code.
-
-
+   * - ``raw:threshold``
+     - float
+     - Libraw parameter for noise reduction through wavelet denoising.
+       The best threshold should be somewhere between 100 and 1000.
+       (Default: 0.0)
+   * - ``raw:fbdd_noiserd``
+     - int
+     - Controls FBDD noise reduction before demosaic.
+       0 - do not use FBDD noise reduction, 1 - light FBDD reduction,
+       2 (and more) - full FBDD reduction
+       (Default: 0)
 
 
 |

src/raw.imageio/rawinput.cpp

@@ -676,6 +676,19 @@ RawInput::open_raw(bool unpack, const std::string& name,
         m_spec.attribute("raw:Demosaic", "AHD");
     }
 
+    // Wavelets denoise before demosaic
+    // Use wavelets to erase noise while preserving real detail.
+    // The best threshold should be somewhere between 100 and 1000.
+    m_processor->imgdata.params.threshold
+        = config.get_float_attribute("raw:threshold", 0.0f);
+
+    // Controls FBDD noise reduction before demosaic.
+    // 0 - do not use FBDD noise reduction
+    // 1 - light FBDD reduction
+    // 2 (and more) - full FBDD reduction
+    m_processor->imgdata.params.fbdd_noiserd
+        = config.get_int_attribute("raw:fbdd_noiserd", 0);
+
     // Values returned by libraw are in linear, but are normalized based on the
     // whitepoint / sensor / ISO and shooting conditions.
     // Technically the transformation for each camera body / lens / setup