Medical video recording

After exiting the recording window or video from file window, the recorded and loaded video materials are shown in the column in the left part of the window A, and next to them - in rows - selected frames (Fig. 1).

Fig. 1. Preview and selection of frames - window embedded in the test window. This arrangement is advantageous when working on a large panoramic screen

Video sequences 1 are represented by their initial frames. No frames are automatically selected from the recording. The series of frames 2 is represented by four frames of the series arranged in a rectangle; by default, the last frame in the sequence is selected. A video sequence is created from the stored single frames 3 (represented in the column by the first frame); by default, all frames are selected and appear on the list. A group of images loaded from a file is shown as a video sequence 4 with all the loaded images in it. Images are displayed on the right side of the video sequence.

Double-clicking on one of the video sequences in the left column, or right-clicking on the sequence and selecting the Frame selection option will highlight it and launch the preview and frame selection window on the right side B (or in a separate large window as in Fig. 2). In this window, new frames from the video material are selected.

Fig. 2. Preview and selection of frames - separate window (markings in accordance with Fig. 5.8). Working in a separate window can be more convenient especially on smaller screens

You can control the preview with the buttons for playback (Play) 5, frame-by-frame (slow-motion) (Slow) 6, pause/resume (Pause) 7and stop (Stop) 8 and the recording scroll bar with a slider 9. The slider is used to set the video sequence at any time of the recording by moving the cursor, as well as frame by frame using the arrow buttons 10 or the arrow buttons on the keyboard. The counter 11 shows the elapsed time in seconds. The 12 and 13 buttons allow you to jump to the previous and next video sequences stored during the examination. The sliders 14 allow you to edit the color of the recording (the share of red and green components). The Image correction option below allows you to automatically improve the brightness and contrast of the image.

The buttons 15 allow you to enlarge the image 1x, 1.7x, 2x or 4x. After zooming in, you can move around the image by dragging the frame with the mouse cursor.

In an additional Frame selection window, it is possible to display as list of all video recordings from the examination on the left side and play them back by clicking on the right frame. To open the recordings list (or hide it), press the recordings list button 16. The current frame is selected using the Shot button 17.

The Scale 18 option allows the user to scale and estimate the length and area of selected objects in the image.

After pressing the button 18 an additional window, Scale determining, opens. The first step is to set the scale on which the estimate will be made. The user determines the scale in the Scale gauge tab (Fig. 3). To set the scale, open a frame or a recording in the Frame selection window, on which an object of known dimensions (e.g. a ruler) will be visible, and then mark with a red line 21 a stretch of length corresponding to the distance set by the user 23. The program automatically reads the line segment in pixels 22 and calculates the scale in millimeters per pixel and the size of the area (image) 24.

Fig. 3. Scale determining window – dimensioning

Fig. 4. Scale determining window – dimensioning

To perform the estimation, in the frame selection window, open the selected frame rep-resenting the examined object and open the Scale determining window ( 18 in Fig. 1, 2) on the Dimensioning tab (Fig. 4). A frame with the object is displayed on the right side of the window. By the colored line segment 25 added to the image, the user marks the object with to estimate the dimensions (e.g. width, length, perimeter of the object). Initially, the image shows a line segment consisting of two points and a straight line between them. To mark a different shape (e.g. the perimeter of an object), add more points by double-clicking the left mouse button nearby, creating any shape. To delete a point, double-click on it with the left mouse button. Next lines with different colors are added by clicking the Add object button 26. Next objects are numbered and added to the image 25 and to the object table 27. The table shows the number of the object, the corresponding line color in the image, an editable description of the object and the automatically measured values of the length L in millimeters and the surface area S in square millimeters (if the perimeter is closed). The description of the object and the measured values are also displayed in the image. Above the table there is an option Draw areas 28, which, when enabled, allows the surface area of an object to be meshed.

In the table it is possible not only to edit the description of the object, but also to set the visibility of the object in the image (button marked with a black dot) or the selected reference object (button marked with a red dot) 29. To make the object invisible on the image, left-click on the button marked with a black dot on the right side of the description. A disabled button (without a visible "dot") indicates a hidden object. Below the button with a black dot is a button marked with a red dot. This button allows marking an object (line length for comparative size estimation) as reference and it is always 100%. After setting one of the objects as reference, the line lengths of the other objects will be converted from millimeters to percentages respectively in relation to the line length of the marked object

The analyzed image with selections, described objects and the values of the length L and the surface area S of the object can be saved and added to the report. To select an image, press the Add picture button 30. The selected image appears in the frame list at the bottom of the window.

When using a separate frame selection window, frames selected from a given video sequence appear in its lower part C and there you can delete them and save them to disk using the context menu. In order to delete or save a selected frame to disk, right-click on the frame and select the option, respectively,Delete or Export - save to disk. To save a frame on a portable CD drive, select the CD DVD drive as the recording location, and then click on the Save these files on CD command.