Freehand Drawing in Image processing toolkit?

Hi,

Is there a freehand drawing property in the IMage processing toolkit? if so, how is it done?

Thanks a lot

Do you mean you want to enable the user to modify the image by drawing on its pixels using the mouse?
If yes, please tell me which LEADTOOLS version (16, 17, etc.) and programming interface (Main OCX, .NET classes, DLL API, C++ Classes, etc.) you are using.

yes please.

I am using Leadtools 17.5 and vb.net.

Bernadette,
One way of doing that is to handle the mouse events (mouse down, mouse move, etc.) and use GDI drawing function of .NET to modify the image pixels.
The following forum post has a VB.NET project that draws lines on an image. Although it only draws lines, you can modify the mouse events handlers so that they perform freehand drawing:
http://support.leadtools.com/SupportPortal/cs/forums/21209/ShowPost.aspx

Hi,

Referring to the link you gave me, what is the difference when I check the UseDPI??

what is DPI?

Thank you :)

Hello,

DPI = Dots Per Inch

This is a value representing the resolution of the display device, or the number of pixels that can be fit within a square inch.

With UseDPI, we account for the resolution defined with the image to make sure it displays properly on the screen.

Hi,

I already got how to do the Freehand Drawing with the RasterImageViewer but I got a problem.

Once I scroll the image and draw, the line is not drawn in the exact position of the mouse.

Thanks for you help.

I tested using the same project I created for you earlier (VB_v175_UseDpi_GDI) but was unable to reproduce the issue.
In that project, I performed drawing while zooming and scrolling, and it always drew the lines in the correct location.
Try to compare your coordinate conversion code to that project. If you still can't find the cause of the problem, please provide me with exact steps to reproduce the issue and if possible a small test project (NOT your full application) that shows the problem.

Here is my test project.

Thanks a lot

And this is the image i've been testing on my test project

thank you

Bernadette,
The problem with your code was that it did not convert the viewer's co-ordinates to the bitmap's co-ordinates.
I have modified your project to convert from the viewer's to the bitmap's co-ordinates. Please take a look and see how this is done.
What I did was that I used RasterImageViewer.ViewerToImagePoint() function to translate the mouse co-ordinates on the viewer to their equivalent on the bitmap and then assigning the new co-ordinates back to the viewer.

Note: You can find 'DDB next to the lines I changed/Added