1. Enhancing the Enlargement of Images
Tara Naughton
Computer Systems Lab

2. Introduction Typically two methods of image enlargement
Pixel replication
Replaces original pixel with group of pixels of the same value
Interpolation
Replaces original pixel with group of expanded pixels
Produce results too jagged or too blurred

3. Fig 1. Pixel replication vs. interpolation

4. Similar Research Focus on keeping defined edges Ramp edge model
Locate edge pixels, derive parameters, derive intensity, keep parameters the same in the enlarged images
Step edge model
Divides image into “atomic areas,” derive step edge parameters for each pixel, find intensity of atomic areas, find step-likeness value to see if near step edge, use step-likeness value as weight to combine intensity values derived for atomic area
Fig 2. Step edge parameters
Fig 3. Ramp edge parameters

5. Background Coding in Python Takes input of black-and-white .pgm images
Outputs enlarged black-and-white .pgm images

6. Discussion Separates images into parts: edges and non- edges
Resize non-edges with interpolation method
Find intensity values for edges and resize accordingly

7. Results Produce images that are neither too blurry nor too jagged
Compare between original, resized image, and images resized by other methods
Currently produces image resized by pixel replication

8. Fig 5. Original image
Fig 6. Image resized by pixel replication (scaled to smaller size, but with changes to image visible)