I require an Android Activity class that can be called by Intent and passed a filename. The Activity will open the camera preview with a light grid to assist the use in taking a straight picture of a white paper with writing. The point will be either for the user to align the left and right edges of the sheet to the sides of the phone screen or align the top and bottom edges, depending on the ratio of the paper size to screen size. When the phone detects the edges are close it will assist the user by overlaying a red box on the gaps until the paper comes within an adjustable degree of matching the edges. When the edges match sufficiently, the boxes will turn green and the overlay will have a count down 3-2-1 and take the picture. Then the image will be reviewed and the user can either accept or retake. The image will be saved in the filename provided with the intent. All of this must be able to be embedded in a different application.