Defining an overlay image

Screen capture can also be frustrated by displaying a second image over the main image. This second image could be some logo or other promotional image but is best made a GIF. The GIF used could be transparent and better still can be made to continuously sweep across the image.

The advantage of using ImageSafe to do this is that editing of the original image isn't necessary and if a GIF is used over a JPEG, the GIF will always appear with it's original quality and crispness. If you were to edit a JPEG and superimpose the GIF with an editing program the JPEG quality would degrade and the sharpness of the GIF will be lost. With ImageSafe the GIF is always pixel-perfect.

Overlay image positioning

The overlay can be positioned in the top-left, bottom-right or center of the main image. Alternatively the exact pixel co-ordinates of the position can be specified. The co-ordinate position is reletive to the top-left corner of the main image.

Making the image move

Any overlay image, even an animated GIF can be made to move over the image. The overlay image always starts at the starting place defined as above and then moves either from left to right, top to bottom, or top-left to bottom-right repeatedly. By pressing the "Time" button it's possible to change the timing parameters of the movement. The parameters that can be changed are: The overlay image will "wrap around" and will always be present over the main image. The ability to move the overlay image over the main image is an excellent obstacle to someone using screen capture to copy an image. It is also an excellent way to draw attention to advertising information such as the owner's logo.

Using a double image

With a larger main image and a smaller overlay image large parts of the main image can still be exposed to screen capture and editing out of the overlay. To better protect against this the "double image" option places two moving images over the main image so when one overlay image is leaving, the other is dead center over the main image.

Previewing

Pressing the preview button will let you see what the image looks like with the overlay before generating the applet. Before the preview button will work, a main image must be first selected using the file chooser on the right hand side of the display.