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Дата изменения: Fri Feb 4 20:38:59 2005
Дата индексирования: Mon Oct 1 20:44:54 2012
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Videocameras

The program allows to observe the images from videocamera and to capture frames, which can be analyzed and processed using FemtoScan program.

It is important to select the proper driver of videodevice before using it. If you do it for the first time, select menu command File/ Capture.../ Video or press button . The window where it is possible to select the driver will appear. Select the driver and press OK button, then the window, showing the movie from the videocamera will appear. Next time when the Command Video is selected or the button is pressed, the driver selection window won't appear any more, and the movie will be seen in a window.

The menu command Video/ Options/ Select video device... is used to change the current driver. This command works as previously described.

To obtain a frame as a picture for further analysis and processing select menu command Video/ Capture frame or press the button . A new window with a video frame will appear. But you canot analyze this image with FemtoScan program, because it is in BMP format and not in SPM-format. It is necessary to convert it for further processing. Take menu command Bitmap/ Convert to spm image. Bitmap conversion options window, shown in fig. 3.4, will appear. Colours will be transferred into heights so that the height is proportional to sum of the intensities of three colors. The colors can be added at different weights as selected in this window. If the option Invert Image is selected, then the program will regard the image as negative and will perform the consequent evaluation of the heights. The image conversion occurs after you pressing Convert button, and then it is possible to analyze and process the image.

Figure 3.4: The window to select the parameters of conversion of raster image into SPM-image

It is possible to obtain images which will correspond to average of several separate frames. The menu command Video/ Capture multiple frames or button are used for this. Select this command and window in which it is possible to select time interval between frames to be averaged and number of these frames, will appear. Press the Start button to start the video frame capturing and averaging. After the programe complete this operation you will see the window Bitmap conversion options (fig. 3.4) instead of the final image. Select the parameters of conversion, press the button Convert and the image in SPM format will appear.

It is possible to configure parameters available in the driver of video device during videocapture using ``FemtoScan'' program. Menu Video/ Options is used for this. The details are not described here, because they may be specific for different video cameras. It is possible to choose to modes of videocapture: -- Overlay or Preview. The image will be sent directly from the videodevice to the videocard in the Overlay mode, and will go via processor in Preview mode. The first mode is better but is not supported by all video cameras.