Video Client 3 (Version 0.92+) Quick Reference

Table of Contents

• Overview
• What's new in Video Client 3
• Features
• Menu description
• Toolbar
• Side Panel
• Keyboard
• Mouse functions
• File formats
• Preferences

Overview

The Video Client 3 is a fast versatile video display and analysis tool used to monitor, taking and analyzing data that is produced by image sources, such as video cameras. The Video Client was originally written for monitoring and measurements at Photo-Injector Test Facility Zeuthen (PITZ). But it is made in a generic way so that it is also useful for other sites than PITZ.

Brief list of possibilities:

• receive live video as well as take sequence of video images from live sources
• monitor what is going on (see electron beam, see laser beam, see dark current, see diagnostic devices in the beam pipe)
• online-analysis of the beam images (spot size, position, shape, ...)
• optimize the beam image quality before data is taken and stored permanently
• do manual data-taking
• do semi-automatic data-taking (control of laser shutter)
• correlate behaviour between spot-size, position and shape and "moving" experiment parameters (Online-DAQ)

Figure 1: Main Application Window

(click to enlarge)

What's new in Video Client 3

• Interface for getting video frames from Server is now Video System 3-style
  • supports JPEG images (will be converted to grayscale on input)
  • supports RGB colour images (will be converted to grayscale on input)
  • support independend x and y scale factor
• Redesigned Interface/Toolbar
• Zoom Panel
• Histogram Panel
• False Colour Table Panel
• Side Panel
• Normalisation now taking into account upper and lower bound (backward compatible upper bound normalisation is available as an option)
• Possibility to tweak X-Ray filtering
• Position and size of area of interest can be finetuned by keyboard (CTRL+arrow-keys, CTRL+shift+arrow-keys)
• works via VNC and Timbuktu
• XML configuration files with speaking names, easily editable via text editor

Features of the program

• Spot position and size calculation using Fourier analysis
• Spot position and size calculation using Straightforward statistics
• False color (classic, JET) and greyscale mode
• projections of the video signal (in X and Y)
• Printing of video images as well as the whole program window
• Live video-mode (polling) and offline mode (grabbing)
• Saving and loading of raw images and backgrounds using application-specific (IMM, IMC) and widely used format (Windows BMP)
• Background subtraction
• Acquiring backgrounds using grab single background, add to background, envelope background and average background
• Snapshot mode (video snapshot to BMP file)
• Automatic acquire of certain control system properties (parameters of the experiment) for simplified correlations (so-called Online DAQ)
• Automatic acquire of certain control system properties in order to save side-by-side of a saved video frame
• Scaled values (instead of pixel values obtain results directly in millimeters)
• Image preview on loading files
• Semi-automatic datataking (called: GrabAndSave) with interfacing of Laser shutter
• X-Ray filtering
• Selectable area of interest either circular or rectangular (all calculations are only done there and not on the whole video frame)
• Cathode bounds superimposed over the image (useful for Virtual Cathode cameras)
• Free field in toolbar with two implemented functions at the moment
• sum of pixel values of video area (Sum of Pixels)
• cooked pixel value under mouse cursor (Cooked Value)
• mean value of pixel values of video area (Z mean)
• rms value of pixel values of video area (Z rms)
• XY Correlation Coefficient of video area (XY Corr (-1..1))
• Tilt factor of video area (XY Tilt)
• XY Angle of Regression Line (XY Angle [°])

More technical:

• works over Remote Desktop (Microsoft Remote Desktop Connection, VNC, Timbuktu)
• compatible with Multi-Monitor setups
• video frame transfer from server to Video Client 3 can use multicasting (configurable)
• XML config file with speaking names
• Video System 3 video data interface (compatible with Video System 3 sources)

Menu description and quick reference of functions

Footnotes:

[1]	In addition, the area of interest (AOI) is automatically reset to the biggest one possible. For rectangular AOI, the AOI will span the whole image dimensions.
[2]	When using grayscale colour mode, there could be problems observing weak signals. The gray scales are linear distributed across the bit-depth of the pixels of the image. Depending on the capabilities of the monitor, only a fraction of the possible gray scales are shown physically.
[3]	PITZ false colour mode was designed for better displaying of weak signals and in order to distinguish low, medium, high and saturated intensity. Black means no, blue means weak, green means medium, red means strong and white means saturated signal.
[4]	The colours are drawn like in MATLAB if JET colour table is used. Slight finetuning has been performed so that the maximum (saturated) intensity of the displayed data is shown as white.
[5]	If there are multiple video frames in the buffer, first of all the value is calculated for each individual frame in the buffer. Then the individual values are averaged. What is shown in the field is then the averaged value.
[6]	Please note that X-Ray filtering and background subtraction are performed before the value is calculated. So if these algorithms are in effect, they may alter this value! In contrast, normalisation is performed after the value is calculated, so applying normalisation does not influence this value.
[7]	Please note that X-Ray filtering, background subtraction and normalisation are performed before the value is calculated. So if these algorithms are in effect, they may alter this value!
[8]	Please note that this value is only calculated if statistics mode is switched to straightforward or fourier.
[9]	Dedicated documentation on XY Correlation Factor, Tilt and Angle of Regression Line is available on the Video System website.
[10]	Any algorithm applied on a sequence of images is designed to perform best if there are no images lost in-between (so-called dropped frames) while recording the sequence. Due to shared resources like network bandwidth, drops may occur. The Video Client 3 will present a warning in this case. Also in rare cases it may happen that the image source is changed on server-side while the Video Client 3 records a sequence. Such events will be detected and an error message will be shown. As the recorded sequence is considered useless in this case, the sequence will be discarded.

Toolbar

Description of the Side Panel

Footnotes:
[1]	The data formats the Video Client 3 supports are: Gray8 (maximum 8 bits per pixel) and Gray16 (maximum 16 bits per pixel). In addition to the format, the effective bits per pixel currently set are shown. For example there exist Gray16 EBitPP=12 which means 16 physical bits per pixel, but the image source is only able to deliver 12 bits per pixel. The remaining 4 bits are not used and will not go into calculations. Only the effective bits are taken into account.
[2]	There are two types of Areas of Interest: Rectangular and Circular. The rectangular area of interest is defined by its bounding rectangle pixel positions left(l), top(t), right(r) and bottom(b). The circular area of interest is defined by its centre point (cx, cy) and its radius (r). There is always an area of interest set inside Video Client 3. The biggest rectangular area of interest spans the whole image dimensions. The biggest circular area of interest is a circle which is restricted to the image dimensions.
[3]	The number is still shown after poll mode has been stopped. It will be cleaned on next startup of poll mode.
[4]	The setting is volatile and so it will be forgotten if the Video Client 3 is closed.
[5]	The current delimiter and decimal point for CSV files are tried to be obtained from Windows regional settings. Furthermore they can be specified in videoclnt3-config.xml. The config file takes precedence over what was obtained from Windows regional settings.

Keyboard-shortcuts

Mouse functions

File Formats

In this section, the different file formats used by the application are explained.

Preferences Dialog