Introduction

Implement the algorithm presented in [1]. You can use the code like below to get a pencil drawing production:

I = PencilDrawing(im, ks, width, dirNum, gammaS, gammaI);

See demo.m for example.

Parameters

I added some more parameters for better control of the final image.

• width

  Control the width of the strokes. See Figure 1 for example.

  

  Figure 1: Width of the strokes. left: width = 0; right: width = 2.

• gammaS

  Control the darkness of the strokes. See Figure 2 for example.

  

  Figure 2: Gamma of the strokes. left: gammaS = 1.0; right: gammaS = 2.0.

• gammaI

  Control the darkness of the final image. See Figure 3 for example.

  

  Figure 3: Gamma of the final image. left: gammaI = 1.0; right: gammaI = 0.4.

Tone Transfer Weights

The paper presented three groups of weights for tone map generation.

1. 

2. 

3. 

These weights will determine the histogram of the tone map. I use the third group by default, which makes the final image lighter. You can change to other groups in GenToneMap.m.

Folder Organization

• inputs

  Include some test images from the website of the publishers and other images.

• pencils

  Include 5 pencil textures for demonstration. I use “pencils/pencil0.jpg” by default. You can change it in PencilDrawing.m.

• results

  Include the results generated by my code. Each image may use different parameters.

• resultsFromPaper

  Include the results of the paper for comparison. I grabbed them in their website.

Reference

[1] Lu C, Xu L, Jia J. Combining sketch and tone for pencil drawing production[C]//Proceedings of the Symposium on Non-Photorealistic Animation and Rendering. Eurographics Association, 2012: 65-73.