Study Two: Differences in JPEG and GIF thumbnails

As in Study One, this study was made to try to see if there was a significant difference between GIFs made from JPEG compressed images and PICT files, at either 72 or 150 ppi. This time, I chose a full size image, to see if size had anything to do with resolution or clarity. The original size was 8.447 x 10.567 inches, and once I scanned the image into a Pict file, and "cleaned it up" with Photoshop, I did not make any further color adjustments or enhancements so that each file could be compared equally.

I also wanted to determine if there was a difference in image quality between thumbnails (150 pixels high) saved as JPEGs with the thumbnails converted to GIFS (from both PICTS and JPEGs).

(Editorial note on the use of this image:
Thank you to Wired Magazine for the use of their cover for this experiment. I am not making the JPEG or PICT files available, because they look too close to the original copyrighted image. Lawyer Benedict O'Mahoney, author of


PICT Scanned at 150 ppi
Converted to GIF
18 K


PICT Scanned at 72 ppi
Converted to GIF
18 K


JPEG at 150 ppi,
Maximum Quality
Converted to GIF
18 K


JPEG at 150 ppi,
High Quality
Converted to GIF
18 K


JPEG at 150 ppi,
Medium Quality
Converted to GIF
18 K


JPEG at 150 ppi,
Low Quality
Converted to GIF
18 K


JPEG at 150 ppi,
Maximum Quality
53 K


JPEG at 150 ppi,
High Quality
53 K


JPEG at 150 ppi,
Medium Quality
53 K


JPEG at 150 ppi,
Low Quality
53 K


JPEG at 72 ppi,
Maximum Quality
Converted to GIF
18 K


JPEG at 72 ppi,
High Quality
Converted to GIF
18 K


JPEG at 72 ppi,
Medium Quality
Converted to GIF
18 K


JPEG at 72 ppi,
Low Quality
Converted to GIF
18 K


JPEG at 72 ppi,
Maximum Quality
53 K


JPEG at 72 ppi,
High Quality
53 K


JPEG at 72 ppi,
Medium Quality
53 K


JPEG at 72 ppi,
Low Quality
53 K


Back to the Beginning

Forward to See the findings of Study Two

Maia Jin, mjin@umich.edu, October 1995