You can draw on an iPad with an Apple Pencil on the Procreate app, which you can use to sketch, paint, and illustrate.

It only takes a few steps to change your image's background color in Photoshop. You'll just need to use the Quick Selection Tool and Quick Mask mode.

Abstract: Considering all or part of the sensors are at known positions, this paper addresses the problem of locating a 3-D moving object with a linear constant velocity trajectory using ...