Existing algorithms for natural image sketch production easily cause such problems as loss of image details and singleness of stroke line. To solve these problems

this study proposes an improved algorithm for natural image pencil drawing production. By simulating the artist creation process of sketch

we adopt a multi-level and multi-scale method to extract details from different image levels. Furthermore

we use strokes of different lengths and thicknesses to simulate the painting effect of different strengths in the process of artist creation

as well as to draw different levels image detail hierarchically. Then

the final sketch stroke effect is obtained by fusing all stroke effect levels. We finally merge the sketch stroke effects and image background to obtain the output image

which exhibits content that is consistent with that of the original input image

tonal effect that is the same as an artist's drawn sketch

as well as stroke and background form that are similar to those of the actual sketch. The output image has a strong sense of reality in terms of sketch effect. A large number of experimental results indicate that the proposed method proposed can generate high-quality natural image pencil drawings. Moreover

the proposed method has strong comparability with the existing mature pencil drawing generation technique.