• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

beginner question

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
Shadowkiller

Shadowkiller

Digital Hunter
Jul 30, 2002
1,272
267
0
44
I think you will find that knocking down the files size from 2-3meg to 100k for posting on this forum will seriously reduce the quality of any pic.

If the pic has few colours, and strong contrast the file size will be smaller initially and quality will stay higher, but a more complex image like F81 posted will suffer from the compression algorithm.
 
loopy

loopy

Deeper Blue Hypoxyphiliac
Oct 24, 2002
719
51
0
40
Hey sash, long time no talk - sent you a bunch of sms but you rarely use your phone ya cheeky bugger :D Send me an email - bradley.drew at defence.gov.au cause I've lost yours :p

Disagree on the first bit - use anything past about photoshop 6, and then select "save for web"... i can save a 2000x3000 pic (ie 6MP) at "low" res (file size about 100k) and it still looks really good. Admittedly though, that's pretty much the only prog I've seen that resizes well.


Cheers,

Brad
 
Shadowkiller

Shadowkiller

Digital Hunter
Jul 30, 2002
1,272
267
0
44
Hey Brad,

Things depend a lot on the pic. After editing over 2000 photos in the last year, I can tell you for dead cert that no compression algorithm is good enough to keep the quality the same when going from 5meg to 100k. Simplistic pics, monochrome especially, do ok, but intricate detail photos, especially with a colourful background, suffer. Edge pixilation is particularly bad, no matter what compression I use in PS7.

Also: My old mobile fell off a crane, so i have a new one. I got your email titled "Hey Dad" so you do still have my email, exams prevent me from replying to the 120 odd emails I got in the last week...
 
loopy

loopy

Deeper Blue Hypoxyphiliac
Oct 24, 2002
719
51
0
40
Wow, I've been smacked! :ban

:D

I tried it out last night though - I have 4682 images from my D70 (taken since April), all at 6 megapixel res (file size is on average about 2-3 meg, depending on colours)... I picked randomly about three dozen pics (with varying numbers of colours/colour distributions) and compressed them. I might have not mentioned before, but I'm including shrinking (from 3000x2000 down to 1800x1200) and applying "medium" compression - all the file sizes were sub 200k, and to look at the original compared to the copy, yeah sure you could tell a few minor diffs, and you've got virtually no zoom quality but stand back a bit and for all intensive purposes its the same pic. I tried fiddling with the compression settings under "Save as" and couldn't get anywhere near the same compression rates while still keeping reasonable quality. I'll try to get a few pics off my comp sent over here to show (takes a while because this computer has no floppy/usb access, so I have to email from a public computer... :()
 
Adrian

Adrian

Deeper Blue Beachcomber
Supporter
Nov 23, 2002
2,691
533
218
68
Brad,
If you can get a hold of one of the PhotoImpact programs, even if it's an older version they have an excellent jpg compression where you can see exactly what you get while comparing it to the original at different compression settings before saving the file. You can download free trial that lasts a month at www.ulead.com

Here's a more specific link, its called Smart Saver Pro as a stand alone, but a similar version is incorporated into the PhotoImpact series all the way back to PhotoImpact 3 I believe.

http://www.ulead.com/ssp/runme.htm

Adrian
 
Last edited:
DeeperBlue.com - The Worlds Largest Community Dedicated To Freediving, Scuba Diving and Spearfishing

ABOUT US

ISSN 1469-865X | Copyright © 1996 - 2022 deeperblue.net limited.

DeeperBlue.com is the World's Largest Community dedicated to Freediving, Scuba Diving, Spearfishing and Diving Travel.

We've been dedicated to bringing you the freshest news, features and discussions from around the underwater world since 1996.

ADVERT