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VNC OVERLAY
REMOTE MICROSCOPE OPERATION SOFTWARE
Description
VNC-Overlay is a modification of VNCViewer that enables overlaying of MPEG4 video in the color-marked areas of remote desktop. This project was initiated to permit full-time remote control of a Philips/FEI XL30FEG scanning electron microscope. The software reproduces the control screen and video signal of the microscope at a remote computer.Essentially, the software performs the video overlay that the microscope computer accomplishes in hardware. Improvements in computer speed (since the original design of the XL series of microscope) have meant that the overlay may be done entirely in software. The SEM video signal of the microsope is captured by a custom videoserver running on a Linux PC. The signal is digitized and sent as an MPEG4 stream encapsulated in IP (see figure 1).
Figure 1
The remote computer uses the VNC-Overlay client software to connect first to the microscope control computer and then to the videoserver which streams the SEM image to the remote computer. The remote computer overlays the video image onto the control software in the same manner as the microscope computer (see figure 2).
Figure 2
The Quicktime movie in figure 3 is recorded in a Campus Square Apartment room at Lehigh University. In the movie, John Mansfield is driving the XL30FEG SEM which is located in the University of Michigan North camps EMAL. Bethlehem is approximately 550 miles (880km) from Ann Arbor. The remote operation is enabled by Internet2.
System Software Components
There are two components in this system:- VNC-Overlay - Windows/Linux VNC client
- MPEG4 MicroStreamer - A simple MPEG4 stream server for Linux. It needs inetd/xinetd and a configured video4linux2 device to run.
Optimal System Specifications
Compiled binaries will work with any Pentium 4 or Athlon CPU. However, using slower components may have adverse effects on video framerate and latency.We have determined that the following main system components work well for us:
VNC-Overlay Client
- 2.0GHz Pentium 4 CPU
- 256MB 266Mhz DDR SDRAM
- 4x AGP SiS Video Adapter
- 2.26GHz Pentium 4 CPU
- 256MB 333MHz DDR SDRAM
- WinTV GO Video Capture Card
- Motherboard with 533MHz Front Side Bus Support
Download
Before you can download any of the files you must agree to the GNU General Public License. It gives you certain rights to modify and use the files available through this webpage. If you do not agree to the GNU General Public License you may not download any file linked to this page. Click here to read GNU General Public License. Copyright holder for VNC Overlay Remote Control System is University of Michigan EMAL. VNC Overlay uses VNCViewer which is copyright of AT&T Laboratories Cambridge, XVID Codec which is copyright of XVID Project, and CommonC++ library which is copyright of GNU Project.
- Installation Instructions from the CD-ROM
- Linux VNC Overlay Client
Make sure to enable execution permissions on install.exe - Windows VNC Overlay Client. No installation is required.
- Linux MPEG4 Video Server. See installation instructions.
- Source code to the VNC Overlay system
- A free VNC server is available from AT&T Laboratories Cambridge
- Registry patch to enable VNC session encryption