This sample program, PXR_VB_NET_GRAB_RT, illustrates the use of the Imagenation PXR800 with
the new programming Visual Basic .NET. It shows you how to grab and display an image and also how to read and write BMP files.
In this sample we allocate a single buffer. The PXR800 is put
into a mode where it is always grabbing another frame in addition to the one that is currently being DMA'd. This gives you the same result as using
two buffers in software. We do not need to set any parameters in order to implement this method. This is the default method for the PXR800.
This method works quite well and will result in a realtime display if a buffer can be copied to the VGA faster than the next grab can take place,
which is either 33 or 40 ms depending camera type. Almost any system today can achieve a realtime display by using this method. Whether you use our
sample as a starting point or not, you will need the interface file contained in
this package if you want to work in Visual Basic .NET.
This is what you need for Visual Basic .NET development:
In order to develop a Visual Basic .NET application for the PXR800, you
need to have an interface file that redefines all of the PXR800 functions and links the new definitions
to the existing PXR800 DLLs.
This is what we are giving you in this package:
The interface file containing the following three types of data:
| 1. | The DLL function redefinitions - Redefines all the functions that
are explained in the the PXR800 Frame Grabber User's Guide and contained in the PXR800 DLLs. |
2. | Global variable definitions – A set of common static variable names used by the PXR800 API. |
3. | Display Form - Some useful functions for displaying images. You may want to use these functions in your own application to to avoid building them from scratch.
|
A sample Visual Basic .NET program that illustrates the following concepts:
| 1. | Library initialization - Proper initialization of the PXR800 libraries. |
2. | Display - Done by getting a pointer to the acquired image using the
PXR800 FrameBuffer() function and then creating a bitmap by calling the Bitmap() function. |
3. | Continuous image update - Uses a timer to cause the image window to be continuously updated.
|
This is how you use it:
Download this package into a directory where you want to work.
Unzip it into that same directory. Build the sample and execute it to make sure it works. Then modify it for your
application. If you are building a new Visual Basic .NET application, you might want to start with our sample code. If you already have an application that you are porting, you may just want to use our interface
file.
