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Commit 6775c1ae authored by Yannick TANGUY's avatar Yannick TANGUY Committed by Yannick TANGUY
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Improve documentation (luminance mode)

parent 066890ff
zonalstats_histogram
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Modules/Applications/AppFiltering/app/otbContrastEnhancement.cxx
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......@@ -154,7 +154,7 @@ private:
"or to reduce the dynamic of the image without losing too much contrast. "
"It offers several options as a no data value, "
"a contrast limitation factor, a local version of the algorithm and "
"also a mode to equalized the luminance of the image.");
"also a mode to equalize the luminance of the image.");
// Documentation
SetDocName("Contrast Enhancement");
......@@ -164,13 +164,14 @@ private:
"over the image and then use the whole dynamic : meaning flattening the "
"histogram. That gives us gain for each bin that transform the original "
"histogram into the flat one. This gain is then apply on the original "
"image. Upon this coarse algorithm we added several option to allow "
"a finer result. First there is the limitation of the contrast. Many "
"ways can be used to do it, we choose to limit the contrast by modifying "
"the original histogram. To do so we clip the histogram at a given "
"height and redistribute equally among the bins the clipped population. "
"Then we add a local version of the algorithm. It is possible to apply "
"the algorithm on tiles of the image. That gives us gain depending on "
"image."
"\nThe application proposes several option to allow a finer result : "
"\n- There is an option to limit contrast. We choose to limit the contrast "
"by modifying the original histogram. To do so we clip the histogram at a "
"given height and redistribute equally among the bins the clipped population. "
"Then we add a local version of the algorithm. "
"\n- It is possible to apply the algorithm on tiles of the image, instead "
"of on the whole image. That gives us gain depending on "
"the value of the pixel and its position in the image. In order to "
"smoothen the result we interpolate the gain between tiles.");
SetDocLimitations("None");
......@@ -195,7 +196,8 @@ private:
"height accepted in a bin on the input image histogram. "
"The maximum height will be computed as hfact*eqHeight where eqHeight "
"is the height of the theoretical flat histogram. The higher hfact, the "
"higher the contrast.");
"higher the contrast."
"\nWhen using 'luminance mode', it is recommended to limit this factor to a small value (ex : 4)");
MandatoryOff("hfact");
AddParameter(ParameterType_Float , "nodata" , "Nodata Value");
......@@ -208,7 +210,7 @@ private:
"for the histogram computation");
AddChoice( "spatial.local" , "Local" );
SetParameterDescription("spatial.local" , "The histograms will be "
"computed on the each thumbnail. Each of the histogram will be "
"computed on each thumbnail. Each of the histogram will be "
"equalized and the corresponding gain will be interpolated.");
AddChoice( "spatial.global" , "Global" );
SetParameterDescription("spatial.global" , "The histogram will be "
......@@ -247,9 +249,14 @@ private:
"Each channel is equalized independently" );
AddChoice( "mode.lum" , "Luminance" );
SetParameterDescription( "mode.lum" ,
"The luminance is equalized and then a gain is applied "
"on each channels. This gain for each channels will depend on"
"the weight (coef) of the channel in the luminance." );
"The relative luminance is calculated thanks to the coefficients."
"Then the histogram is equalized and then a gain is applied on each channels."
"This gain for each channels will depend on"
"the weight (coef) of the channel in the luminance."
"\nNote that default values come from color space theories "
"on how human eyes perceive colors)"
);
AddParameter(ParameterType_Group , "mode.lum.red" , "Red Channel" );
AddParameter(ParameterType_Int , "mode.lum.red.ch" , "Red Channel" );
SetDefaultParameterInt("mode.lum.red.ch", 0 );
......@@ -300,12 +307,6 @@ private:
FloatVectorImageType::RegionType::SizeType size;
size = inImage->GetLargestPossibleRegion().GetSize() ;
// if ( !HasUserValue("spatial.local.w") )
// SetParameterInt( "spatial.local.w" , size[0] );
// if ( !HasUserValue("spatial.local.h") )
// SetParameterInt( "spatial.local.h" , size[1] );
if ( GetParameterString("spatial") == "local" &&
HasValue("spatial.local.h") && HasValue("spatial.local.w") &&
HasValue("bins") )
......@@ -320,26 +321,6 @@ private:
!HasUserValue("mode.lum.green.ch") &&
!HasUserValue("mode.lum.blue.ch") )
SetDefaultValue( inImage , "RGB" );
// if ( HasUserValue("minmax.manuel.min") &&
// HasUserValue("minmax.manuel.max") )
// {
// if ( GetParameterFloat( "minmax.manuel.min" ) >
// GetParameterFloat( "minmax.manuel.max" ) )
// {
// float temp = GetParameterFloat( "minmax.manuel.min" );
// SetParameterFloat( "minmax.manuel.min" ,
// GetParameterFloat( "minmax.manuel.max" ));
// SetParameterFloat( "minmax.manuel.max" , temp );
// }
// else if ( GetParameterFloat( "minmax.manuel.min" ) ==
// GetParameterFloat( "minmax.manuel.max" ) )
// {
// std::ostringstream oss;
// oss<<"Warning minimum and maximum are equal."<<std::endl;
// otbAppLogINFO( << oss.str() );
// }
// }
}
if ( GetParameterString("minmax") == "manuel" )
......
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