Pulling objects out of an image

The term cutting has various meanings in the field sof photography and image editing. Photographers understand that it can mean images that have been taken with an open aperture so that they have less depth. This causes the theme of the image to appear sharp while objects in the foreground and background are blurred. They are pushed back and become part of the background.

In image editing circles, the term cutting frequently refers to cropping the desired object down to size. This procedure is easily handled by an image manipulation program. Difficulties do arise however when the term is used to refer to the extraction of an object from a current background so that it stands against a transparent background. This extraction function is important if you want to work on any type of collage. Therefore, if you want to extract an object from one image and place it in another, you will need to be able to use this function.

If you have ever tried to extract an object from an image, you probably know the problems that can occur during the procedure. Images taken with a digital camera almost always have areas in which the object and background seem to melt into one another (Figure 1). Closer observation reveals that there is no sharp delineation between the object and the background. Many of the details flow into one another. Automatic processes like color choice and magnetic scissors do not work reliably here. Another related problem is that the edges of the object that has been extracted need to be edited so that when added to a new image the object has edges that melt seamlessly into the new background.

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