Image Eraser Control

We would like an image eraser control developed in WPF that we can plug into our existing application. This control needs to? allow a user to erase a background of an image using controlled brush sizes and hardness (feathering)control. This erase must make the erased area transparent and not simply paint the selected area white. This control must provide an interactive menu to allow a user the ability to set the brush diameter size and the erased edge hardness. As the user initiates the eraser ? the mouse pointer must disappear and the diameter of the eraser control be shown to the user. The user would erase by mouse strokes. It is also required that the user be able to select two points and the area between the two selected points would be erased. This control must be able to handle a several megabyte image and the control must respond smoothly. This eraser control would be similiar to Adobe Photoshop eraser control.