Optimum method of image acquisition using sawtooth-shaped-function optical signal to improve grey-scale resolution

The subtle changes in the images are determined to some extent by the grey-scale resolution. This paper presents a method used for optimizing the grey-scale resolution of the acquired images. The optical source is modulated by the sawtooth-shaped-function signal, and the acquired images by the sensor are processed by the frame accumulation technology. Compared to the traditional method using the optical source with constant intensity, this method can greatly improve the grey-scale resolution of images by more than 1 bit under the condition of low energy light. Based on the method, we can not only obtain higher quality images but also conserve energy, which is very important in the field of fluorescence imaging, biomedical imaging, face recognition and security system.