Optimization And Analysis Of Digital Screening With Error Diffusion Method

Digital screening technology,also known as digital halftone technology,is a technology that uses computers to realize image reproduction on binary devices based on the human visual system.It is mainly used in image storage,watermarking,compression and other technologies,and widely used in the textile industry,medical industry and other fields.Therefore,the research of digital screening technology has very important meaning and practical value in realizing image reproduction.This thesis focuses on the error diffusion algorithm with better comprehensive performance in digital screening,and separately describes the distribution of error filter coefficients,the selection of thresholds,and the design of scanning paths in more detail.The current scanning methods adopted by the error diffusion method have their own advantages and disadvantages,and the line scanning method will cause the image to have the problem of harmful texture and hysteresis related to the scanning direction.Although the space-filling curve scanning method effectively restores harmful textures,it introduces noise.Therefore,in order to solve the problem of image hysteresis caused by line scanning in the traditional Floyd-Steinberg error diffusion method,this thesis firstly proposes a recursive scanning path,an error diffusion method based on twodimensional alternating scanning paths.Experimental results show that the algorithm improves the hysteresis related to the scanning direction to a certain extent,and for images with the same length and width,the processing speed of the algorithm is the same as the F-S error diffusion method.In view of the obvious structural texture,harmful texture and edge blur in the traditional error diffusion method,this thesis proposes an error diffusion method based on edge enhancement and double error filter based on the improvement of the twodimensional alternate scanning path.This method uses Shiau-Fan filter,HVS model filter and edge enhancement Sobel operator to solve the problem of harmful texture in the screening process.The simulation results show that the screened image obtained by the improved process has a good visual effect,not only the detailed information of the original image is more completely retained,and some harmful textures are reduced,but the edge part is also enhanced.Finally,the self-made inkjet printing system based on Arduino open source hardware and HP C6602 A inkjet print head is used to verify the double-error filter screening algorithm based on edge enhancement proposed in this thesis.The printing result of the screened image shows that the algorithm in this thesis improves the problem of edge blurring in the traditional error diffusion method,and the structure of the screened image obtained by the processing is closer to the original image,and the visual effect is better.