1. Using Script-Fu in the GNU Image Manipulation Program to Automate “Smart” Sharpening
Benjamin Bucior
Northwest Guilford High School, Greensboro, NC
Summer Ventures in Science and Math
Visual and Image Processing
Rahman Tashakkori and Jere Miles
Appalachian State University
July 28, 2007

2. Background/Objectives
Gimp- GNU Image Manipulation Program
Free, open-source, similar to Photoshop
Convolution matrices, Unsharp mask sharpening, “Smart” sharpening
Script-Fu, Scheme, Parenthesis
Goals: Compare methods of image sharpening, automate “smart” sharpening with Script-Fu

3. Gimp and “Smart” Sharpening works in Windows, Linux, BSD, Solaris, and OS X

4. Methods Understand Script-Fu Procedure Browser Kate/Notepad++
Common bugs:
gimp_image_new vs. gimp-image-new
(set! var car(value)) vs. (set! var (car (value)))
string_value vs. “string_value”

5. “Smart” Sharpening Duplicate image, extract Value channel from HSV
Create sharpening layer on original image using Value channel
Edge detect duplicate image, filter results
Add edge mask to sharpening layer
Unsharp mask on sharpening layer
Technique by Eric R. Jeschke, tutorial at

6. Results
Compare different sharpening techniques on an image, evaluate advantages/disadvantages
Original image, Convolution matrix, Unsharp mask, “Smart” sharpening
Photo of trellis at Boone Gardens

7. Original Image

8. Convolution Matrix

9. Unsharp Mask

10. “Smart” Sharpening

11. Convolution
Original
Unsharp
“Smart”

12. Conclusions “Smart” sharpening was best method Photos of plants
Unsharp masking second
Photos of plants
Anti-aliasing: “jaggies”
Script-Fu easy, could automate other common processes (5 days)
Tweaking parameters improves restoration
“Smart” sharpening ineffective on heavy blurring
Script could be improved

13. Future Work “Smart” sharpening script: Photo restoration:
More options (guided process, more undo levels)
Allow script to batch process images
Determine better default parameters
Photo restoration:
Red-eye removal
Reduce image noise
Correct heavy blurring

14. Acknowledgements My parents: Andrew Bucior, Jr., and Barbara Bucior
My siblings: Andrew Bucior III, Matthew Bucior, Sarah Bucior, and Samuel Bucior
The Gimp Developers and Documentation Team
Eric R. Jeschke
(Gimp Portable)
Dr. Rahman Tashakkori and Jere Miles
Counselors at Summer Ventures
Ryan Belt and Allison Nelson