Observing and Showing
· Watching Videos
· Observing Motion
· Zooming and using Magnification
· Deinterlacing and Forcing image aspect ratio
· Configuring for high-speed cameras
· Mirroring Images
· Adjusting image quality
· Using overlay grids
· Summarizing videos with the Overview function
· Playing motion backward with Reverse
· Commenting and drawing on key images
· Using and creating observational references
Watching Videos
1. Opening and playing a video
Use the file explorer to navigate to the folder where your video is stored. The thumbnails panel, on the right, displays the files that can be opened for the selected folder.
Double click on a thumbnail to open the video in a Player screen.
You can also use the menu File > Open or drag a file from the Windows Explorer to Kinovea to open the corresponding file.
Once the video is opened, launch the playback with the player controls or browse to an arbitrary location with the navigation cursor.
2. Specifying a working zone
Move to an interesting period and use the working zone start button .
Launch playback and let it run until the end of the sequence to analyze. Hit the working zone end button .
Note: The navigation cursor is now more precise, since it expands in the Working Zone. If the playback is in loop mode, the video will loop within the Working Zone.
3. Increasing image size
If image seems too small, use the little square handles at the image corners.
Drag them until you are pleased with the image size.
You can also directly zoom in the image or use the magnifier tool.
4. Slowing down playback speed
In order to better study the motion, slow down playback speed using the speed cursor.
To go back to 100% speed, double-click on the percentage value.
To change speed by small amounts, use the UP ARROW and DOWN ARROW of the keyboard.
To jump to the next 25% spot, use CTRL + UP ARROW or CTRL + DOWN ARROW.
Observing Motion
1. Specifying a working zone for analysis
With the help of the selection cursors and set a small working zone around the motion to observe.
Once the working zone is short enough, Kinovea will switch to Analysis mode. In this mode the frames composing the video are extracted to memory for faster access.
Automatic switch to analysis mode
The working zone properties corresponding to the switch to Analysis mode can be set in the Preferences dialog, at Play/Analysis Screen tab.
The default duration is 12 seconds.
2. Breaking down motion
Analysis mode makes the video update in real time when using the navigation cursor. This gives you total control on the timeline.
You can also use the mouse wheel to move a few frames forward or backward.
Zooming and using the magnifier
1. Zooming
Use CTRL + Mouse Wheel to zoom in the image or unzoom.
Move the zoomed image by dragging it around with the hand tool .
2. Using the magnifier
Click the magnifier button in the drawings tool bar .
Hover your mouse on the image: the magnified zone shows up in the top left corner of the image.
Click on image to temporary fix the source zone.
Four little corners are displayed around the source zone to resize it.
Move the source zone to focus on another detail of the action.
Move the magnification result window to avoid hiding an interesting part of the image.
To change the magnification factor, right click on either the source zone or the magnification result.
Choose one of the other magnification factor, from 1.5x to 2.5x of the original size of the source zone.
Deinterlacing and Forcing image aspect ratio
Deinterlacing
If you are dealing with interlaced video source, you may experience interlacing artifacts (sometimes known as comb artifacts).
To remove the interlacing artifacts on the images of the video, use the menu Image > Deinterlace.
Before and after using the menu Deinterlace.2. Forcing image aspect ratio
Kinovea tries to detect the image aspect ratio specified in the video file.
If this automatic detection fails, you can force the video to be displayed to a known image aspect ratio.
Use the menu Image > Image Format and choose one of the preset options, Force 4:3 or Force 16:9.
If you are constantly dealing with videos for which Kinovea cannot detect the image aspect ratio, you can permanently force an image format from the Preferences dialog.
Configuring for high-speed cameras
High-speed capture - Slow motion playback
High-speed camera record videos at a very high frame rate and store them in a video file with a normal frame rate.
For example, a high-speed camera may record images at 1000 frames per seconds and create a video specifying that it should be displayed at 30 frames per seconds.
When played back, the video will appear in slow motion.
By default, the times displayed in Kinovea are based on the playback frame rate, since it is the only information encoded in the video.
Hence, when playing back a video captured with a high-speed camera, the times displayed will not match the captured event time.
You can specify the capture frame rate of the high-speed camera by right clicking the image to bring the main contextual menu and then use Set Original Speed…
Configuring the high-speed camera recording frame rate.
All time related informations displayed in Kinovea will use this information (i.e: current position, working zone duration, stopwatches, etc.).
Mirroring Images
To display a video as if was seen through a mirror, use the Image > Mirror menu.
The Mirror function might be especially useful when comparing two videos.
Adjusting image quality
When the image is in Analysis mode (see Observing Motion) and the frames are extracted to memory, you can adjust the quality of images in the video.
1. Auto levels
Use the Image > Auto Levels… menu to enhance the color of the image.
Before and after applying Auto Levels…2. Auto contrast
Use the Image > Auto Contrast… menu to enhance the contrast of the image.
.Before and after applying Auto Contrast…
3. Sharpen
Use the Image > Sharpen… menu to emphasize edges in the image. This may help enhance a slightly blurred video.
Before and after applying Sharpen…Using overlay grids
1. Using the flat grid
Toggle the menu Image > Grid. A grid is displayed on the image.
The flat grid allows you to make observations on a plane strictly perpendicular to the camera axis.
Move the grid by drag and drop and resize it using the circular handles at corners.
Note: The number of divisions can be adjusted by right clicking the grid then using the Configure menu.
2. Using the perspective grid
Toggle the menu Image > Perspective Grid.
Use the circular handles at the corners to map the grid on a rectangular plane, visible or virtual.
For instance place the grid on a plane that would be perpendicular to the ground to make a visualization guide.
To expand the grid while keeping the mapping on the same virtual plane, hold the CTRL key down during the drag and drop. The number of divisions is also adjustable through the context menu Configure.
Note: You can also toggle the perspective grid display with the dedicated button on the tool bar of the player screen .
3. Changing grids color
Display the configuration dialog box of a grid by double clicking on it. Change the grid color so as to have a good contrast with the video content.
Summarizing videos with the Overview function
The Overview function is a summary image of the video.
It samples images from the video at regular interval and creates a composite picture where you can see the motion at a glance.
To enable Overview, toggle the menu under Motion > Overview.
Set the number of images to use for the composition and the orientation of the motion.
The default orientation is left-to-right, which means the first image of the series will be in the top left corner and the last one in the bottom right corner.
When you enable the Overview, all playback controls are disabled.
You can save the Overview by right-clicking the image and using the menu Save the Current Image to File.
To return to normal display, toggle off the menu Motion > Overview.
To close the Overview and return to normal display, you can also use the Close button of the screen .
Playing motion backward with Reverse
The Reverse function lets you play the motion backward.
It simply revert the order of the images in the working zone.
To enable the Reverse function, use the menu Motion > Reverse.
To return to forward playback, use the Reverse function again.
Commenting and drawing on key images
A Key Image is a time position of special interest. It could be a reference image you would like to enrich with comments, a technical pose you want to highlight with lines or arrows, a key point in the motion flow, etc.
Manipulating Key Images is done with the dedicated tool bar under the main video display.
1. Adding key images
Move to the position of interest and click the Add Key Image button .
The Key Images toolbar unfolds and a thumbnail of the current image appears.
Each image from the video can be turned into a Key Image.
To remove an image from the Key Image list, use its close button in the upper right corner of the thumbnail : .
2. Adding a comment to a key image
When the video is stopped on an existing Key Image, the Key Image thumbnail has a blue contour.
Use the Show Comment button : to display the comments window.
By default, the title zone is filled with the time marker of the image.
Change the title as you see fit and add a comment in the bottom zone.
You can move and resize the comment window for easier editing.
3. Adding drawings
Click on the drawing tool button of your choice and then click anywhere in the image. A drawing is added.
After a drawing has been created, you can move and resize it.
You can change the color and style of the drawing using right-click and Configure menu or by double clicking it.
Double click the label to edit the text.
You can resize the label by dragging the lower right corner away or by changing the font size in the configuration dialog.
/ Pencil (Free-hand drawing)/ Line and arrows
To turn a simple line into an arrow (or double arrow), right-click the line and use the Color and size… menu.
/ Circle/ Cross marker
/ Angle
Note: Angle measurement is only meaningful when the angle measured is on a plane perpendicular to the camera axis.
4. Removing drawings
To remove a drawing, right-click it and choose Delete.
When a Key Image is deleted, all the drawings that were added to it are also deleted.
5. Default color and style
Default color and style is determined by the color profile at the time the tool is used.
You can access the color profile dialog from the button on the key image toolbar.
You can change the color of each drawing type independently.
When you change the default color or style, the drawings that are already present on the video will not change.
You can configure a drawing color and style just before you add it, by right clicking on the image while the drawing tool is selected.
Using and creating observational references
1. Observational references
Observational references are images or illustrations that you overlay on the video. They can be used for quick qualitative biomechanics and visual comparison with preset reference frames. They are essentially arbitrarily complex static drawings that you can modify to your liking.
To add an observational reference on the video, use the menu Image > Observational reference.
Kinovea comes with a few observational references bundled that will be listed under this menu.
2. How does it work
The observational reference framework is open and extensible.
- It is based on the SVG open standard. (The shape of the drawing can be stretched or squeezed without losing quality like it would with another image format).
- You can create your own reference tool or modify the existing ones in external SVG editors like Inkscape.
- It is totally extensible: simply copy a .svg file in the "guides" directory of Kinovea program files folder, it will be automatically listed in the menu.
In addition to SVG, you can also load regular images (in JPEG, PNG, GIF or BMP format), for example to compare the performance with a snapshot from another video.
You can create sub folders under the "guides" directory to better organize your collection of observational reference. The hierarchy will be respected and sub menus created.
3. Manipulation
Move the reference around by dragging it. Resize it with the corner handles (height/width ratio will be kept).
To change the opacity of the reference, right click it and choose Opacity. In the dialog that opens, set a value between 1 and 100%.
4. Loading from file
To load a reference from a file, use the menu Image > Observational reference > Import image…