  This paper presents, for the first time, an image enhancement methodology
designed to enhance the clarity of small intestinal villi in Wireless Capsule
Endoscopy (WCE) images. This method first separates the low-frequency and
high-frequency components of small intestinal villi images using guided
filtering. Subsequently, an adaptive light gain factor is generated based on
the low-frequency component, and an adaptive gradient gain factor is derived
from the convolution results of the Laplacian operator in different regions of
small intestinal villi images. The obtained light gain factor and gradient gain
factor are then combined to enhance the high-frequency components. Finally, the
enhanced high-frequency component is fused with the original image to achieve
adaptive sharpening of the edges of WCE small intestinal villi images. The
experiments affirm that, compared to established WCE image enhancement methods,
our approach not only accentuates the edge details of WCE small intestine villi
images but also skillfully suppresses noise amplification, thereby preventing
the occurrence of edge overshooting.
