/// <summary>
/// Find groups of Extremal Regions that are organized as text blocks.
/// </summary>
/// <param name="image">The image where ER grouping is to be perform on</param>
/// <param name="channels">Array of single channel images from which the regions were extracted</param>
/// <param name="erstats">Vector of ER’s retrieved from the ERFilter algorithm from each channel</param>
/// <param name="groupingTrainedFileName">The XML or YAML file with the classifier model (e.g. trained_classifier_erGrouping.xml)</param>
/// <param name="minProbability">The minimum probability for accepting a group.</param>
/// <param name="groupMethods">The grouping methods</param>
/// <returns>The output of the algorithm that indicates the text regions</returns>
public static System.Drawing.Rectangle[] ERGrouping(IInputArray image, IInputArrayOfArrays channels, VectorOfERStat[] erstats, GroupingMethod groupMethods = GroupingMethod.OrientationHoriz, String groupingTrainedFileName = null, float minProbability = 0.5f)
{
IntPtr[] erstatPtrs = new IntPtr[erstats.Length];
for (int i = 0; i < erstatPtrs.Length; i++)
{
erstatPtrs[i] = erstats[i].Ptr;
}
using (VectorOfVectorOfPoint regionGroups = new VectorOfVectorOfPoint())
using (VectorOfRect groupsBoxes = new VectorOfRect())
using (InputArray iaImage = image.GetInputArray())
using (InputArray iaChannels = channels.GetInputArray())
using (CvString s = (groupingTrainedFileName == null ? new CvString() : new CvString(groupingTrainedFileName)))
{
GCHandle erstatsHandle = GCHandle.Alloc(erstatPtrs, GCHandleType.Pinned);
ContribInvoke.CvERGrouping(
iaImage, iaChannels,
erstatsHandle.AddrOfPinnedObject(), erstatPtrs.Length,
regionGroups, groupsBoxes,
groupMethods,
s, minProbability);
erstatsHandle.Free();
return(groupsBoxes.ToArray());
}
}
