Dynamic Surface Detail Transfer

The image-based surface detail transfer is a technique that uses 2-D image operations to transfer geometric details from one surface to another, thus producing the visual effects of added geometric details. In order to improve the computational efficiency and automation, a new technique called dynamic transfer of surface details is introduced. The new technique has the property that its computational complexity is independent of image resolution. As a result, it is capable of transferring geometric details at high speed on high resolution digital images. It also relieves the users from the burden of having to specify the smoothing parameters for images of different resolutions or different head sizes, thus making the system more intelligent and much easier to use.The image-based surface detail transfer is shown to be an effective technique for blemish removal. However, no matter whether it is applied to transfer geometric details from one image to another or to remove blemishes on a single image, the technique requires Gaussian smoothing with a user specified σ, which is determined by the visual inspection on the module of geometric details by the user. On application of blemish removal, the visual inspection includes the judgment on the size of a blemish. Perceptual analysis from the user based on visual observation makes the technique difficult to use. Because it is difficult to estimate the size of a blemish accurately by visual observation, the user has to try different σ values to evaluate the effectiveness of the blemish removal. Every time the user modifies σ, it has to apply Gaussian smoothing to the entire image which can be time consuming for high resolution images. In contrast, our new technique does not require the user to specify σ . The horizontal and vertical smoothing coefficients σ₁ and σ₂ are instead determined dynamically based on the sizes of the blemishes in an automatic way. Moreover, smoothing operation is only applied to those pixels which are necessary for detail transfer thus avoiding the time consuming operation of smoothing the entire images.The dynamic transfer of surface details is a significant improvement over the traditional image-based surface detail transfer technique. It dramatically reduces the computational complexity, and furthermore, it removes blemishes in a more automatic and resolution-independent way. It is a significant step forward of the image-based surface detail transfer technique, and a valuable contribution to the image enhancement research. It also brings up interesting new research directions in this area.