ACAM_64
7.2.7 Persistance Control
This control adjusts the persistence of the image. This is the equivalent of the exposure time for an optical
camera. A persistence of a 200 to 300 ms is recommended for most applications. A longer persistence
will allow the averaging of the image over longer time periods, and therefore present images with less
noise. But events occurring at short intervals will blur from one to the next. A shorter persistence will allow
the tracking of more dynamic events, at the expense of noisier images.
7.2.8 Lin/Log Button
In Lin mode, the brightness of the pixel is proportional to the pressure-squared received from the
corresponding direction. In Log mode, the brightness of the pixel is proportional to the level in dB received
from the corresponding direction. Log mode allows the representation of a wider dynamic range of levels,
but it also tends to produce images with less sharp details.
7.2.9 Interpolation Button
When this button is pressed, the 32x32-pixel image is interpolated to 128x128 pixels. When not pressed,
the window shows the raw 32x32 image. The interpolation is performed by the PC, so on some low-end
PCs the interpolation process can slow-down the image presentation.
7.2.10 Palette Button
This control selects a monochrome or polychrome palette. On some images, a polychrome palette allows
more details to be visible in the low-level part of the dynamic range.
7.2.11 AutoTrack Button
When this button is pressed, the audio beamformer will track the highest-intensity pixel in the image. The
audio produced by the camera will automatically follow and focus on the source as it moves across the
field of view. When the mode is not set to AutoTrack, the cursor can be moved manually to any pixel in
the image.
7.2.12 FOV Button
The user can choose between two fields of view: 60 deg or 90 deg. Changes from one field of view to
the other take time, as the camera must be completely reprogramed for the new field of view. The choice
of field of view is persistent across connections/disconnections.
7.2.13 Record Button
A movie can be recorded by pressing this button. The recording starts when the button is pressed and
stops when the button is pressed for a second time. When the recording stops, the application will ask
where to store the recorded file.
7.2.14 Playback Button
A previously recorded movie can be played back by pressing the Play button. The application then asks
to point to the recorded file. The recorded file plays at normal speed. The playback can be paused by
pressing the Pause button at any time. After the complete file has played, the playback system is left in
pause mode at the last image of the file. Pressing the Play button while a file is being played will abort
the playback.
7.2.15 Pause Button
Pressing the Pause button during playback will pause the image. At that time, the scrubber bar can be
moved manually to quickly change locations in the file.
7.2.16 Scrubber bar
While the playback is paused, the scrubber bar can be used to quickly move the playback to a new
position in the file.
