Image enhancement of colloidal crystals Kossel diffraction

Kossel-line diffraction method is an important way to measure the structure of crystals. Colloidal crystal is one of the hotspots on the condensed physics research. In order to obtain the diffraction image, a 473nm wavelength laser is used to irradiate samples, and then the Kossel-line image of sample is projected onto the translucent screen and recorded by charge coupled device (CCD) camera. However, the dark Kossel-line is not distinct enough due to the strong background. Besides, the images we get have low contrast ratio. Therefore a novel image enhancement method primarily based on Butterworth highpass filter (BHPF) and Laplacian of Gaussian (LOG) operator is proposed to make the Kossel-line clearness.