reasoft
site map storedownloads
Preparing Graphics for The Web

JPEG COMPRESSION EXAMPLE


jpeg compression example JPEG Quality (1-99): Q99
Filesize: 31,505 bytes
Load Time @1.3k/sec: 24.2 sec
Load Time @2.6k/sec: 12.1 sec

Although the strings are a little crisp on the edges, the 24-bit color depth lends richness to the wood tones and subte grays in the tuning pegs. Even at the minimum compression level, the file size was reduced 84% from the original TIFF file! There is no noticable degradation from the original.

jpeg compression example JPEG Quality (1-99): Q90
Filesize: 13,673 bytes
Load Time @1.3k/sec: 10.5 sec
Load Time @2.6k/sec: 5.3 sec

Absolutely indistiguishable from the previous image, yet half the filesize. Isn't compression wonderful?

jpeg compression example JPEG Quality (1-99): Q80
Filesize: 9.686 bytes
Load Time @1.3k/sec: 7.5 sec
Load Time @2.6k/sec: 3.7 sec

Less than a third of the first image's filesize, and still no visible image degradation.

jpeg compression example JPEG Quality (1-99): Q70
Filesize: 7,934 bytes
Load Time @1.3k/sec: 6.1 sec
Load Time @2.6k/sec: 3.1 sec

Still a great image, but the filesize reduction is becoming less and less significant. We could just go with this one, since experience tells us that we can't trim any more than a few more seconds off the load time before the image quality is noticably affected, but let's remember that every bit of reduction we can squeeze out of each image can add up to something significant. Let's keep going.

jpeg compression example JPEG Quality (1-99): Q60
Filesize: 6,872 bytes
Load Time @1.3k/sec: 5.3 sec
Load Time @2.6k/sec: 2.6 sec

This is getting a little boring. Having dome this so many times before, I know that the image is beginning to suffer, but I still can't really see it.

jpeg compression example JPEG Quality (1-99): Q50
Filesize: 6,191 bytes
Load Time @1.3k/sec: 4.8 sec
Load Time @2.6k/sec: 2.4 sec

Boring. When is this damn thing going to start getting ugly?

jpeg compression example JPEG Quality (1-99): Q40
Filesize: 5,566 bytes
Load Time @1.3k/sec: 4.3 sec
Load Time @2.6k/sec: 2.1 sec

Still looks fine to me.

jpeg compression example JPEG Quality (1-99): Q30
Filesize: 4,876 bytes
Load Time @1.3k/sec: 3.8 sec
Load Time @2.6k/sec: 1.9 sec

Still looking good. And look at the filesize! Less than 5k! Imagine how impressed your friends will be amazed when this image just "pops up" on their tube.

jpeg compression example JPEG Quality (1-99): Q20
Filesize: 4,084 bytes
Load Time @1.3k/sec: 3.1 sec
Load Time @2.6k/sec: 1.6 sec

OK, its not perfect, but for this particular image, this amount of compression is acceptable. Barely. So do we stick with this image for our page, or for a measly 800 bytes or more, do we back up and choose a cleaner one?

jpeg compression example JPEG Quality (1-99): Q10
Filesize: 3,129 bytes
Load Time @1.3k/sec: 2.4 sec
Load Time @2.6k/sec: 1.2 sec

For the first time, we can clearly see the chunky patches resulting from the compression. We've gone too far.

jpeg compression example JPEG Quality (1-99): Q1
Filesize: 2,209 bytes
Load Time @1.3k/sec: 1.7 sec
Load Time @2.6k/sec: 0.8 sec

Finally. Total Chaos. So bad, it's good.

Shown below is a collage of samples taken from each of the 11 images above. Each sample image represents one of the tuning pegs at 6 times normal size. They are arranged from left to right, top to bottom, from lowest compression to highest, to allow you to directly compare the effects of the compression.

© Douglas E. Gray.


You can convert RAW, JPG, GIF images, prepare photos for the web with ReaJPEG - batch photo editing software and raw converter.
   
News-list:
product updates, new releases
Downloads ReaSoft Store Technical Support Product Forums Contact Us Site Map

Copyright © 2001-2017 ReaSoft Development.
All rights reserved.
Use of this website signifies your agreement to the Online Privacy Policy.