Brace

Half draw

Full draw

Bow tiller tool by Pablo d'Angelo

Quick usage guide:

• Setup camera so that the grip is located in the center (green line). It is important that the camera looks perfectly perpendicular to the bow, otherwise the display will be misleading.
  The green line can be shifted by either setting the y0 parameter of by clicking in the middle of the screen.
• Click on a point on the left limb of the bow.
• Default tiller curve is circular. The size of a stiff grip can be adjusted in the parameter dialog, or by clicking the upper border of the image.
• For elliptical tiller, the vertical radius radius_y can be adjusted in the options or by clicking on the right side of the image.
• If the contrast between limb and background is high, the point will turn green and track the limb while it is exercised. In poor contrast or confusing backgrounds, the tracking can be lost, and the point is shown in red color. To restart tracking, click on the limb again.
• For non circular or elliptical tillers, try enabling the transparent option. This will overlay a transparent, mirrored view, so that both limbs can be compared easily.
• Screenshots of brace, half draw and full draw are made automatically when the track point is active. The images are shown below the live view and can be saved with right click or long touch.
• If the video is shown upside down, click on the upside_down option

Source code available at GitHub. Uses HTML code and image processing jsfeat.