Shape-free hybrid image

Abstract

Hybrid image is the image that changes interpretation according to viewing distance. By simply extracting the low and the high spatial frequency bands from two source images, the combination result image can be interpreted differently by viewing distance. This research finds the way to allow construction of hybrid image regardless of the source image's shape. Without the need to carefully pick the two images to be superimposed, hybrid image can be extended to use with any kind of image contents. There are two approaches for accomplishing shape-free hybrid image. Noise-inserted approach forces observers to perceive alternative low frequency image as meaningless noises in a close viewing distance, by manipulating contrast and details in the high frequency image. Color-inserted approach helps attract the visual attention for the high frequency image perception is also introduced in this research. Finally, hybrid image recognition experiment proves that our proposed method yield a better recognition rate over the original method while preserving hybrid image characteristic.