fill OCR zones with different transparent background colors

i'd like to fill OCR Zones with transparent background colors, for examples i want red for title zones, yellow for flow text zones and green for Graphics zones.

Can you send me an example in C# for leadtools v.15?

Thanks.

Hello,

You can draw a transparent rectangle on the zone that you want by using the following code:
+-------------+
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
Dim G As Graphics
Dim Clr As Color

Dim ZoneLeft, ZoneTop, ZoneWidth, ZoneHeight As Integer
' Zone dimensions
ZoneLeft = 300
ZoneTop = 300
ZoneWidth = 300
ZoneHeight = 300

Const ALPHA As Byte = 128
G = RasterImageViewer1.Image.CreateGdiPlusGraphics().Graphics

clr = Color.FromArgb(ALPHA, 0, 0, 100)
G.FillRectangle(New SolidBrush(Clr), New RectangleF(ZoneLeft, ZoneTop, ZoneWidth, ZoneHeight))
+-------------+

Please let me know if this helps.

Thanks,
Maen Badwan
LEADTOOLS Technical Support

your code is correctly executed but nothing happens.
i've tried your code to the OCR Demo adding a menu item that exec your sample code after a zone is manually selected.

Can you give me more info?

Thanks

Simone

Hello,

Since you are testing this issue using the C# OCR demo, you need to use the following code to draw the rectangle on the Zone:
+----------------+
private void menuItem1_Click(object sender, EventArgs e)
{

RasterImage img = _viewer.Image.Clone();
Graphics G = img.CreateGdiPlusGraphics().Graphics;
          
Color Clr;

int RectLeft, RectTop, RectWidth, RectHeight;
const Byte ALPHA = 128;
RasterDocumentZoneData  _zoneData = _rasterEngine.GetZone(0, 0);

RectLeft = _zoneData.Rectangle.Left-1;
RectTop = _zoneData.Rectangle.Top-1;
RectWidth = _zoneData.Rectangle.Width+2;
RectHeight = _zoneData.Rectangle.Height+2;
          

Clr = Color.FromArgb(ALPHA, 0, 0, 100);
G.PageUnit = GraphicsUnit.Pixel;
if (G.IsVisible(new RectangleF(RectLeft, RectTop, RectWidth, RectHeight)))
{
G.FillRectangle(new SolidBrush(Clr), new RectangleF(RectLeft, RectTop, RectWidth, RectHeight));
               
_rasterEngine.LockPage(0, true);
_rasterEngine.UpdatePage(img, 0);
_rasterEngine.LockPage(0, false);
               
UpdateViewedPage();
}
+----------------+

Please let me know if this helps.

Thanks,
Maen Badwan
LEADTOOLS Technical Support

Now it works fine but i lost the focus to the OCR Zone. I want the focus in the zone when i click on it and i want to change its dimensions like in OCR Demo.

Can you help me?

Thanks

Hello,

Try to use the following code:
-----------------------------------
const Byte ALPHA = 128;

RasterImage img = _viewer.Image.Clone();
Graphics G = img.CreateGdiPlusGraphics().Graphics;
Rectangle rc = new Rectangle(new Point(0,0),_viewer.Image.ImageSize);
Color Clr;
Clr = Color.FromArgb(ALPHA, 0, 0, 100);
int RectLeft, RectTop, RectWidth, RectHeight;
                     
int index = _rasterEngine.SelectedZoneIndex;
RasterDocumentZoneData  _zoneData = _rasterEngine.GetZone(0, index);
           
RectLeft = _zoneData.Rectangle.Left-1;
RectTop = _zoneData.Rectangle.Top-1;
RectWidth = _zoneData.Rectangle.Width+2;
RectHeight = _zoneData.Rectangle.Height+2;         

G.PageUnit = GraphicsUnit.Pixel;
            
if (G.IsVisible(new RectangleF(RectLeft, RectTop, RectWidth, RectHeight)))
{
G.FillRectangle(new SolidBrush(Clr), new RectangleF(RectLeft, RectTop, RectWidth, RectHeight));                
               
_rasterEngine.LockPage(0, true);
_rasterEngine.UpdatePage(img, 0);
_rasterEngine.LockPage(0, false);
                                
_viewer.DrawPage = false;
_rasterEngine.ActivePage = 0;
_viewer.DrawPage = true;
               
_rasterEngine.FindZones(0, rc);
               
_viewer.Refresh();  
               
_rasterEngine.SelectZone(G, 0, index, true);
}
-----------------------------------

Thanks,
Maen Badwan
LEADTOOLS Technical Support

the last raw of your code is wrong because  after the findzones() method is called the index of the zones change so the instruction:

_rasterEngine.SelectZone(G, 0, index, true);

doesn't give the original selected zone but a zone with that index.

 I tried to change your code in:

Rectangle rc = _zoneData.Rectangle;

and

_rasterEngine.SelectZone(G, 0, 0, true);

so only the zone in the rc coordinates(equals to original selected zone) should be selected but it doesn't work properly because a strange zone is selected.

Have you any idea?

Thanks

Hello,

I checked the code and it works correctly.

If you feel that there is a problem in the index of the selected zone, you can use the same code that you are using to select the zone, but you can use the SelectZoneByPoint method instead of SelectZone method as follows:
-----------------------------
Rectangle rc = _zoneData.Rectangle;
_rasterEngine.SelectZoneByPoint(G,0,new Point(rc.Left, rc.Top));   
-----------------------------

Please let me know if this helps.

Thanks,
Maen Badwan
LEADTOOLS Technical Support