The Motion Amplification software can support all of the following filters as described in detail below. They can be applied individually or in combinations. In all of the examples below, the areas in green will be included in the video while the areas in red will be excluded. Because of their behavior, only one Bandpass, one Lowpass, and one Highpass filter can be applied to a video. You can use all three on the same video, but only one of each type. You can add as many Bandstop Filters as you need.
Bandpass Filtering
A bandpass filter will only allow frequency content between the low and the high cutoff to be amplified. All other frequency content will be excluded from amplification. When you select "Bandpass" from the "Type" dropdown, you will be allowed to enter your "Low Cutoff" and "High Cutoff" values. You can either use the keyboard to type values into the fields directly, or use the cursor to drag the red circles on the spectrum display to the area of interest. In the example below, only motion related to frequencies between 16.6 Hz and 17.8 Hz will be amplified in the video.
Lowpass Filtering
A lowpass filter will only allow frequency content below the high cutoff to be amplified. All other frequency content will be excluded from amplification. When you select "Lowpass" from the "Type" dropdown, you will only be allowed to enter your "High Cutoff" value. You can either use the keyboard to type the value into the field directly, or use the cursor to drag the red circle on the spectrum display to the area of interest. In the example below, only motion below 3.8 Hz will be amplified in the video.
Highpass Filtering
A highpass filter will only allow frequency content above the low cutoff to be amplified. All other frequency content will be excluded from amplification. When you select "Highpass" from the "Type" dropdown, you will only be allowed to enter your "Low Cutoff" value. You can either use the keyboard to type the value into the field directly, or use the cursor to drag the red circle on the spectrum display to the area of interest. In the example below, only motion above 16.6 Hz will be amplified in the video.
Bandstop Filtering
A bandstop filter will exclude frequency content between the low and the high cutoff limits and all other frequency content will be amplified. When you select "Bandstop" from the "Type" dropdown, you will be allowed to enter your "Low Cutoff" and "High Cutoff" values. You can either use the keyboard to type values into the fields directly, or use the cursor to drag the red circles on the spectrum display to the area of interest. In the example below, all motion EXCEPT frequencies between 16.6 Hz and 17.8 Hz will be amplified in the video.
Complex Scenarios
The above filters can be combined to create complex scenarios. Below is an example where the intention is to include the 40 Hz and the 120 Hz frequency content in the amplification process. Three filters are required. First, a highpass with a cutoff just below the lower frequency of interest. Second, a bandstop between the two frequencies of interest. Finally, a lowpass with a cutoff just above the higher frequency of interest. As noted on the right-hand side of the window, the green portions of the spectrum are the only frequencies that will be included in the amplification process. The red and grey portions of the spectrum will be excluded.
The filters that have been applied are listed in the Recording Information.
