/// <summary>
/// Extracts text regions from image
/// </summary>
/// <param name="image">Source image where text blocks needs to be extracted from. Should be CV_8UC3 (color)</param>
/// <param name="er_filter1">Extremal Region Filter for the 1st stage classifier of N&M algorithm [Neumann12]</param>
/// <param name="er_filter2">Extremal Region Filter for the 2nd stage classifier of N&M algorithm [Neumann12]</param>
/// <param name="regions">Output list of regions with text</param>
public static void DetectRegions(InputArray image, ERFilter er_filter1, ERFilter er_filter2, out Point[][] regions)
{
using (var vecRegions = new VectorOfVectorPoint())
{
NativeMethods.text_detectRegions(image.CvPtr, er_filter1.CvPtr, er_filter2.CvPtr, vecRegions.CvPtr);
regions = vecRegions.ToArray();
}
}
/// <summary>
/// Converts MSER contours (vector<Point>) to ERStat regions.
/// </summary>
/// <param name="image">Source image CV_8UC1 from which the MSERs where extracted.</param>
/// <param name="contours">Input vector with all the contours</param>
/// <param name="regions">Output where the ERStat regions are stored</param>
public static void MSERsToERStats(InputArray image, Point[][] contours, out ERStat[][] regions)
{
using (var vecRegions = new VectorOfVectorERStat())
using (var vecContours = new VectorOfVectorPoint(contours))
{
NativeMethods.text_MSERsToERStats(image.CvPtr, vecContours.CvPtr, vecRegions.CvPtr);
regions = vecRegions.ToArray();
}
}
/// <summary>
/// This one has no documentation in OpenCV sources or knowledge base
/// </summary>
/// <param name="image">Original RGB or Greyscale image from wich the regions were extracted</param>
/// <param name="channel">Vector of single channel images CV_8UC1 from wich the regions were extracted</param>
/// <param name="regions">Regions extracted by DetectRegions function</param>
/// <param name="groups_rects">The output of the algorithm are stored in this parameter as list of rectangles</param>
/// <param name="method">Grouping method (see GroupingModes). Can be one of { OrientationHorizontal, OrientationAny }</param>
/// <param name="filename">The XML or YAML file with the classifier model. Only to use when grouping method is OrientationAny</param>
/// <param name="minProbablity">The minimum probability for accepting a group. Only to use when grouping method is OrientationAny</param>
public static void ErGrouping(Mat image, Mat[] channels, Point[][] regions, out Rect[] groups_rects, GroupingModes method, string filename = null, float minProbablity = 0.5f)
{
using (var vecChannels = new InputArray(channels))
using (var vecRegions = new VectorOfVectorPoint(regions))
using (var vecRects = new VectorOfRect())
using (var input = new InputArray(image))
{
if (null == filename)
{
filename = string.Empty;
}
NativeMethods.text_erGrouping2(input.CvPtr, vecChannels.CvPtr, vecRegions.CvPtr, vecRects.CvPtr, (int)method, filename, minProbablity);
groups_rects = vecRects.ToArray();
}
}
/// <summary>
///
/// </summary>
/// <param name="image"></param>
/// <param name="msers"></param>
/// <param name="bboxes"></param>
public virtual void DetectRegions(
InputArray image, out Point[][] msers, out Rect[] bboxes)
{
if (disposed)
throw new ObjectDisposedException(GetType().Name);
if (image == null)
throw new ArgumentNullException("nameof(image)");
image.ThrowIfDisposed();
using (var msersVec = new VectorOfVectorPoint())
using (var bboxesVec = new VectorOfRect())
{
NativeMethods.features2d_MSER_detectRegions(
ptr, image.CvPtr, msersVec.CvPtr, bboxesVec.CvPtr);
msers = msersVec.ToArray();
bboxes = bboxesVec.ToArray();
}
GC.KeepAlive(image);
}
/// <summary>
/// Detect MSER regions
/// </summary>
/// <param name="image">input image (8UC1, 8UC3 or 8UC4, must be greater or equal than 3x3)</param>
/// <param name="msers">resulting list of point sets</param>
/// <param name="bboxes">resulting bounding boxes</param>
public virtual void DetectRegions(
InputArray image, out Point[][] msers, out Rect[] bboxes)
{
ThrowIfDisposed();
if (image == null)
{
throw new ArgumentNullException(nameof(image));
}
image.ThrowIfDisposed();
using (var msersVec = new VectorOfVectorPoint())
using (var bboxesVec = new VectorOfRect())
{
NativeMethods.HandleException(
NativeMethods.features2d_MSER_detectRegions(
ptr, image.CvPtr, msersVec.CvPtr, bboxesVec.CvPtr));
GC.KeepAlive(this);
msers = msersVec.ToArray();
bboxes = bboxesVec.ToArray();
}
GC.KeepAlive(image);
}
