Amplify is an image processing technique in Wave Player that enhances or amplifies small movements in a video for easier visual recognition. This can be used, for example, to highlight and troubleshoot vibrations in a mechanical system.
Amplify works best when the source video has low noise and minimal background movement such that the region of interest where motion is occurring remains in the same place in the video. The frame rate should be approximately 5-20x higher than the highest motion frequency of interest. (In certain cases, frame rate aliasing can also be used to visualize even higher frequencies.)
A dedicated graphics card with at least 4GB of VRAM is required to use Amplify. Note that due to memory restrictions the 1.3.0 release of Amplify only works with 2K images. 4K images can be used as source material but they will be downscaled to 2K, processed, then upscaled back to 4K. This limitation may be addressed with further memory optimization in a future release. MacOS 1.4.2 adjusts to 2K for preview but exports at 4K.
The following subsections explain the adjustable parameters used by Amplify.
This determines which features sizes are considered for motion amplification. Small features are at the low end of the scale and large features at the high end. Good results can usually be obtained by leaving at the default settings of 0 - 8. For Height settings below 640, better results may be obtained by setting the high end of the scale to 7 or 6.
This is the amount of amplification applied to the motion. Settings of around 5 to 10 are usually quite good. Too high a gain can cause noise and unwanted artifacts to appear. A gain of 1 is equivalent to Amplify being turned off.
This is the frequency range over which motion amplification is applied. The left slider is a high-pass filter and the right slider is a low-pass filter. The high-pass filter is effective for removing any unwanted bulk movement in the video, for instance caused by slow panning or operator jitter. The low-pass filter can be used to reduce noise and improve the visual appearance of the video.
It is usually best to start with the low-pass filter fully to the right (off) and tune the high-pass filter for best visualisation of the motion. Then the low-pass filter can be used to reduce noise if necessary. Alternatively, if the frequency of the movement under study is known then set the range accordingly to bring out that motion.