public LeadRect Bounds { get; set; }
A LeadRect that contain the coordinates of the zone in pixels.
Calling IOcrPage.AutoZone will return zones with Bounds coordinates that do not overlap with each other. It is the developers responsibility when modifying the zones of the page to make sure the coordinates of those zones follow the same rule.
The coordinates of the zone is in pixels.
Also the IOcrPage.GetZoneBoundsInPixels method can get the coordinates of any zone in pixels.
using Leadtools;
using Leadtools.Codecs;
using Leadtools.Ocr;
using Leadtools.Forms.Common;
using Leadtools.Document.Writer;
using Leadtools.WinForms;
using Leadtools.Drawing;
using Leadtools.ImageProcessing;
using Leadtools.ImageProcessing.Color;
// Assume Form1 is a Windows.Forms form in your application
// The OCR engine we are using
private IOcrEngine _ocrEngine;
// The OCR page we are using
private IOcrPage _ocrPage;
// Our raster image viewer instance
private RasterImageViewer _viewer;
public Form1()
{
InitializeComponent();
// Initialize the raster image viewer
// Turn on use DPI, center the image, add border padding and frame shadow to show that our calculations will be
// independent on all of those extra options
_viewer = new RasterImageViewer();
_viewer.Dock = DockStyle.Fill;
_viewer.BackColor = SystemColors.AppWorkspace;
_viewer.UseDpi = true;
_viewer.BorderPadding.All = 8;
_viewer.FrameSize = new SizeF(1, 1);
_viewer.FrameShadowSize = new SizeF(2, 2);
_viewer.SizeMode = RasterPaintSizeMode.Normal;
_viewer.HorizontalAlignMode = RasterPaintAlignMode.Center;
_viewer.VerticalAlignMode = RasterPaintAlignMode.Center;
_viewer.AutoDisposeImages = true;
_viewer.InteractiveMode = RasterViewerInteractiveMode.None;
// Turn on scale to gray painting in the viewer
RasterPaintProperties props = _viewer.PaintProperties;
props.PaintDisplayMode |= RasterPaintDisplayModeFlags.ScaleToGray;
_viewer.PaintProperties = props;
// Subscribe to the viewer events we need
_viewer.KeyDown += new KeyEventHandler(_viewer_KeyDown);
_viewer.MouseDown += new MouseEventHandler(_viewer_MouseDown);
_viewer.PostImagePaint += new PaintEventHandler(_viewer_PostImagePaint);
Controls.Add(_viewer);
_viewer.BringToFront();
// Create and startup the OCR engine
_ocrEngine = OcrEngineManager.CreateEngine(OcrEngineType.LEAD);
_ocrEngine.Startup(null, null, null, LEAD_VARS.OcrLEADRuntimeDir);
// Load an image into the OCR document
string tifFileName = Path.Combine(LEAD_VARS.ImagesDir, "Ocr1.tif");
_ocrPage = _ocrEngine.CreatePage(_ocrEngine.RasterCodecsInstance.Load(tifFileName, 1), OcrImageSharingMode.AutoDispose);
// Do auto zone
_ocrPage.AutoZone(null);
// AutoZone does not specify a name for the zones, so loop through all the zones and set their names
// to a unique value. We will use the name in the paint code later
IOcrZoneCollection ocrZones = _ocrPage.Zones;
for (int i = 0; i < ocrZones.Count; i++)
{
OcrZone ocrZone = ocrZones[i];
// Construct the name from the ID
ocrZone.Name = string.Format("Zone {0}", ocrZone.Id);
ocrZones[i] = ocrZone;
}
// Show the same image in the viewer
_viewer.Image = _ocrPage.GetRasterImage();
// Note, the image we got from GetRasterImage is a copy of the image in the engine
// Since we set the AutoDisposeImages of the viewer to "true", the image will be disposed
// when the viewer is disposed at application termination
Text = "+ to zoom in, - to zoom out, enter to return to 100%. Select the zones with the mouse";
}
protected override void OnFormClosed(FormClosedEventArgs e)
{
// Dispose the page
_ocrPage.Dispose();
// Shutdown the OCR engine
_ocrEngine.Dispose();
base.OnFormClosed(e);
}
private void _viewer_KeyDown(object sender, KeyEventArgs e)
{
const double zoomRatio = 1.2;
double scaleFactor = _viewer.ScaleFactor;
switch (e.KeyCode)
{
case Keys.Add:
case Keys.Oemplus:
// Zoom in
scaleFactor *= zoomRatio;
e.Handled = true;
break;
case Keys.Subtract:
case Keys.OemMinus:
// Zone out
scaleFactor /= zoomRatio;
e.Handled = true;
break;
case Keys.Enter:
scaleFactor = 1;
e.Handled = true;
break;
}
const double minimumScaleFactor = 0.05;
const double maximumScaleFactor = 11;
scaleFactor = Math.Max(minimumScaleFactor, Math.Min(maximumScaleFactor, scaleFactor));
// Check if scale factor has changed
if (scaleFactor != _viewer.ScaleFactor)
{
_viewer.BeginUpdate();
// Yes, zoom keeping the center of the image
// Get what you see in physical coordinates
Rectangle rc = Rectangle.Intersect(_viewer.PhysicalViewRectangle, _viewer.ClientRectangle);
// Get the center of what you see in physical coordinates
PointF center = new PointF(rc.Left + rc.Width / 2, rc.Top + rc.Height / 2);
Transformer t = new Transformer(_viewer.Transform);
// Get the center of what you see in logical coordinates
center = t.PointToLogical(center);
_viewer.ScaleFactor = scaleFactor;
// Bring the original center into the view center
t = new Transformer(_viewer.Transform);
// Get the center of what you saw before the zoom in physical coordinates
center = t.PointToPhysical(center);
// Bring the old center into the center of the view
_viewer.CenterAtPoint(Point.Round(center));
_viewer.EndUpdate();
}
}
private void _viewer_MouseDown(object sender, MouseEventArgs e)
{
// Perform hit-testing on the zones
if (_ocrEngine != null && _ocrEngine.IsStarted && _ocrPage != null && e.Button == MouseButtons.Left)
{
// Get the transform of the viewer
// Use the transform that takes the DPI into consideration since we turned that on
using (Matrix matrix = _viewer.GetTransformWithDpi())
{
Transformer t = new Transformer(matrix);
// Convert the mouse click coordinates from physical (viewer) to logical (image)
PointF point = new PointF(e.X, e.Y);
point = t.PointToLogical(point);
// Hit test the zones
// An alternative to calling HitTestZone is to loop through all the zones
// and get the value of .Bounds in pixels, then check if the point is inside
// the boundaries.
LeadPoint lPoint = new LeadPoint((int)point.X, (int)point.Y);
int zoneIndex = _ocrPage.HitTestZone(lPoint);
if (zoneIndex != -1)
{
// We hit a zone, loop through all the zones, unselect all but the hit tested zone
for (int index = 0; index < _ocrPage.Zones.Count; index++)
{
// Since OcrZone is a structure, we cannot simply do
// ocrZone.Zones[index].Name = value
// We have to get a copy of the structure, modify it and set it back
OcrZone ocrZone = _ocrPage.Zones[index];
if (index != zoneIndex)
ocrZone.Name = null;
else
ocrZone.Name = "Selected";
_ocrPage.Zones[index] = ocrZone;
}
// Re-paint the viewer to show the new zones
_viewer.Invalidate();
}
}
}
}
private void _viewer_PostImagePaint(object sender, PaintEventArgs e)
{
// Draw the zones on the viewer in their correct location
if (_ocrEngine != null && _ocrEngine.IsStarted && _ocrPage != null)
{
// Get the transform of the viewer
// Use the transform that takes the DPI into consideration since we turned that on
using (Matrix matrix = _viewer.GetTransformWithDpi())
{
Transformer t = new Transformer(matrix);
Pen normalPen = new Pen(Color.Blue, 1);
Pen selectedPen = new Pen(Color.Red, 2);
selectedPen.DashStyle = DashStyle.Dash;
foreach (OcrZone ocrZone in _ocrPage.Zones)
{
// Get the zone bounds in pixels
// You can also use _ocrPage.GetZoneBoundsInPixels here
RectangleF zoneBounds = new RectangleF(ocrZone.Bounds.Left, ocrZone.Bounds.Top, ocrZone.Bounds.Width, ocrZone.Bounds.Height);
// This rectangle is in image (logical) coordinates with top-left view perspective
// Convert to the physical coordinates of the viewer
zoneBounds = t.RectangleToPhysical(zoneBounds);
// Now draw this zone on the viewer surface
if (ocrZone.Name == "Selected")
e.Graphics.DrawRectangle(selectedPen, zoneBounds.X, zoneBounds.Y, zoneBounds.Width - 1, zoneBounds.Height - 1);
else
e.Graphics.DrawRectangle(normalPen, zoneBounds.X, zoneBounds.Y, zoneBounds.Width - 1, zoneBounds.Height - 1);
// Draw the zone name on the left hand corner of the zone
// Note, in a real application you might want to have an option to show/hide the zone names (labels)
SizeF labelSize = e.Graphics.MeasureString(ocrZone.Name, Font);
RectangleF labelRectangle = new RectangleF(zoneBounds.X, zoneBounds.Y - labelSize.Height, labelSize.Width, labelSize.Height);
e.Graphics.FillRectangle(Brushes.Yellow, labelRectangle);
e.Graphics.DrawString(ocrZone.Name, Font, Brushes.Black, labelRectangle.X, labelRectangle.Y);
}
}
}
}
static class LEAD_VARS
{
public const string ImagesDir = @"C:\LEADTOOLS23\Resources\Images";
public const string OcrLEADRuntimeDir = @"C:\LEADTOOLS23\Bin\Common\OcrLEADRuntime";
}