Vectorizer

makes a vector shape layer based on the composite image contents.

1. Open any image.
2. By default, the script selects on the picture the darker areas. To use the lighter areas, just invert the image color (fig. 1) by pressing [Ctrl+I] keys.
3. In the Effects panel, double-click the "Vectorizer" thumbnail.
4. In the dialog box that opens, play with the "Threshold" slider to achieve the best black-to-white ratio (fig. 2). Now the darker areas of your image are selected (fig. 3).
5. There appears the "Refine Edge" dialog. If necessary, smooth the jagged edges to round the outlines of the created path (fig. 3).

1. 

2. As result, you get a new vector shape layer. To change its color call the Color Picker by double-clicking on the "Color Fill" layer thumbnail (fig. 5).