Camera controller

The camera controller is showed by any Live Acquisition App for controlling an instrument which is using cameras. When initially started, it appears as a live acquisition sub-window containing a dark gray rectangle over a light gray area, the former representing the camera resolution or CCD.

The principal mode of interaction with the camera is by right-clicking anywhere. The camera menu appears showing all possible controls.

If X or Y motors are defined for the camera, motion control sliders are shown near the sides of the window.

Hint

Streaming

Streaming can be started/stopped from the camera menu by setting the Streaming flag (first menu entry). Streaming means the user interface is continuously receiving and showing images. After a few seconds from when it is started, frames will be displayed in the gray area. If the streaming is subsequently stopped, the last frame will remain visible.

Streaming images will not interfere with a running test. It can be started, stopped and resumed without any effect on actual image analysis and acquired data.

The image viewed in the controller can be quickly zoomed in/out by using the mouse wheel. The Fit view action, accessible from the context menu, will resize back the image so it fits the window.

Saving the current frame

The current frame can be saved with Save frame camera menu entry. The first frame you save you will be asked a destination directory where to save current and all future frames.

That directory will be remembered for each time you click on Save frame and frames will be saved there with increasing sequence numbers.

All samples contained in the frame will be saved in separate images having the same sequence numbers.

File names will have the format <name>_smp<N>_<seq>.jpg where <seq> is the sequence number increased each time you save, <N> is the sample number, <name> is the camera name. For example: Left_smp0_12.

Simulation

The Analysis flag activates image analysis on the received frames. This flag can be changed only when no test is running.

Simulation can be used before starting a real test, in order to validate the image quality. For example, to check that sample borders and limits are correctly detected, or that motors react in the right way to sample movements.

Imaging

Most important digital imaging options are displayed in the camera menu, submenu Imaging, as a slider with an associated spinbox. You can either control the slider position or write the desired number in the spinbox and press Enter.

Available imaging options:

  • Exposure (should be in range 1-1000)
  • Contrast
  • Brightness
  • Gamma (should be minimum possible)
  • Saturation (should be minimum)
  • Hue (should be minimum)

Hint

On most models it is advisable to use the spin-box to control the exposure. High values (>1000) might freeze the camera.

Motion Control

Camera position can be controlled by up to four motors roles, depending on your instrument’s hardware:

  • X, lateral
  • Y, vertical
  • Angle, angular
  • Focus, focus distance, usually shared by (and affecting) all cameras

If those motors are available, their movement can be set from the camera menu, submenu Motion.

Each motor role shows an additional submenu called after its name, with those entries:

  • A slider, to control the position.
  • A Zoom checkbox, allowing to zoom in or out from the motion range for fine movements.
  • An Is moving? flag: can be unset to block the motor (but cannot be set).
  • A Set zero position action: define any current motor position as the new zero.
  • A Configure motor action: opens the extended configuration panel for the motor.
  • A Configure encoder action: opens the motion-to-image optical encoder configuration panel.

Moreover, X and Y motors are represented directly in the camera controller as a bottom slider (X) and a lateral slider on the left (Y). A right click on these sliders opens a context menu showing the current position and offering a Configure action to open motor configuration panel.

The motion sliders allow to focus-in by double-clicking anywhere on them.

There is a third way to interact with camera positioning: the motion handle. It is displayed as a red square in the top-left corner of the image. Dragging and dropping it around the image will cause a motion such that the new position of the top-left corner of the image will correspond to the position where you dropped the square.

Finding the sample on camera

Upon instrument initialization cameras should automatically be positioned very near to the sample. As Misura instrument allow Free Sample Positioning, motion control must then be used to exactly find the sample or the part of it which should be analyzed (eg: the border).

This positioning can usually be carried out with provided X, Y motion controls (were present) or with manual micrometrical axis tables.

Adjusting the focus

All Misura ODP instruments allow Free Sample Positioning. Before starting a test, the user must manually adjust the focus distance with the provided focus motion controller.

As the focus motor is only one and affects all cameras in the instrument, its motion control is usually showed in a priviledged position as a slider on the bottom of the acquisition window.

In case multiple cameras are used (horizontal dilatometer or fleximeter), care must be taken at positioning the sample perpendicularly to the alumina holding rods, in order to have the same focus distance for all of the cameras.

Focusing the sample is an iterative procedure, where the focus slider is moved back and forth until the optimal focus distance is found.

Morphometrics

The Morphometrics submenu allows to visualize some of the results obtained from image analysis. The results will be displayed as lines overlaid on the original frames.

The most useful analysis overlay is the Region of Interest, which can be activated by the View Regions action. Each sample defined for the camera will be surrounded by a colored rectangle, representing the area of analysis. This rectangle can be resized by dragging and dropping two hook points on the top-left and bottom-right corners.

Restricting the region of interest allows to individually select samples when more than one is viewed by the same camera. It is also useful to filter out imperfections, like dirt on holding plate or camera CCD.

The Reset Regions action will restore the default region sizes.

Then we have ovalyays, which are realtime visualization of some aspects of the analysis being performed.

Generic overlays:

  • Grids: this overlay will draw a grid over each sample.
  • Profile: the border detected as the sample will be overlaid by a blue line, and the area of the sample with a faded blue.
  • Values Label: a movable label is added. The label will contain lines in the form name: value, where name stays for any sample option and value shows the current value for that option (e.g.: height).
  • Pixel Calibration: the Pixel calibration tool discussed below.

Heating Microscope HSM overlays:

  • Points: relevant profile point are highlighted with circles.
  • Base and Height: (only for Heating Microscope HSM) two perpendicular segments starting from the bottom-left starting point of the sample, representing base and height.
  • Circle Fitting: (only for Heating Microscope HSM) a circle representing the best circular fitting to the profile.

Horizontal Optical Dilatometer, Vertical Optical Dilatometer, Absolute Optical Fleximeter overlays:

  • Reference line: position of the sample border at the beginning of the test.
  • Regression line: actual detected position of the sample border.
  • Filtered profile: profile fragments which were actually included in the calcuation of the regression line, after noise filtering.

Samples

The concept of sample is fundamental to understand the camera controller, the management of ROI and the image analysis. From the point of view of the camera, a sample is a portion of image, delimited by a ROI, which can be analyzed in some way to extract results. This not always correspond to the concept of physical sample known to the instrument’s operator.

For example, a sample is a cylinder of pressed powder used for Heating Microscope HSM analysis. In this case, the sample known to the camera is the same physical sample intended by the operator.

The situation is less intuitive in the case of dilatometers or fleximeters. In this case, the operator places one physical sample, but two (or more) cameras view just one side of it. Each side is viewed as a separate sub-sample, one assigned to each camera.

The samples are defined in the active instrument. The camera just points to them, and use them to analyze images and associate output results.

A camera can view one or more samples at the same time. The number of defined samples is available under the Number of samples option in the camera configuration panel. The camera defines an equivalent number of sub-options, accessible by clicking on the right + button, each pointing to the sample which should be used for the corresponding sample number.

Each sample defines its own image analyzer configuration. The advanced user can thus fine-tune image analysis parameters for each sample in the image, separately, making simultaneous multi-standard analysis straight-forward.

Active samples are shown in the camera menu, as Sample <N> menu items where <N> is the sample index from 0 (first sample) to the number of samples minus one.

Each sub-menu contains these items:

  • Configure: opens the sample configuration panel, where image analysis results are stored. From the object tree on the left, it is possible to access to the image analysis option. Some true/false flags are repeated as menu items.
  • Balck/white levelling: convert the grayscale image to black/white. Color levels are accessible from the image analysis configuration panel.
  • Adaptive threshold: convert grayscale image to black/white. Color levels are adaptively calculated point-by-point as a function of neighborhood intensities.
  • Dynamic regions: activate ROI auto-follow.

Advanced configurations

The complete camera configuration panel is reserved for service purposes.

Pixel calibration

A visual tool to calibrate the translation between CCD pixels and real sample’s microns. Reserved for service purposes.

Troubleshooting

To forcefully restart a camera which is no longer working correctly follow these steps:

  1. Open a camera controller, either from an instrument using it or from the global configuration panel.
  2. Right click on the camera frame. Select Configure action.
  3. Locate the Running acquisition option and set its value to Stopped.
  4. Back to the controller. Ensure the camera is Streaming by activating the corresponding context menu option.
  5. The camera will try to restart itself. On repeated failures, Soft-Restart the server. On continued failure, Rebooting the embedded controller.