Solved

Photoshop and image sizes? Just wondering.

Posted on 1997-09-07
3
275 Views
Last Modified: 2010-04-25
Hi,

I was just wondering: in PhotoShop 3.0, the preview box in the bottom left-hand corner shows my image sizes as twice what the finder says they are.

To be specific: 400 x 286 pixels x 3 channels: PhotoShop quite logically tells me I have a 400 x 286 x 3 / 1000 = 343K image. The finder tells me it's 170-odd.

Also the PhotoShop Bible tells me that the _second_ number in the box should be the same as the first, if there is only one layer. It isn't, it's slightly smaller: 315.

This isn't an actual problem, but I'm forever converting from RGB to indexed for the web and checking out the size, but the box is giving me weird information -- am I crazy, or what?

johnny99
0
Comment
Question by:johnny99
3 Comments
 
LVL 4

Accepted Solution

by:
jshamlin earned 50 total points
ID: 1540523
You're not crazy - those numbers are *never* accurate in regard to the size the file will be when it's saved.  What's more, it's even worse for WWW formats.

When you save a GIF of JPEG, the file size is reduced algorithmically - and the precise degree of reduction depends on the actual content of the image.  (I've tried creating a "calculator" to no avail).

And so - the only answer to "how will I know" is  "experience" - after creating graphics for a while, you should get the "feel" for about how large a given image should be.

If you want to shoot for maximum optimization, I'd suggest using an automated tool: Debabelizer (if you can spare the cash) of GIF Wizard (http://www.gifwizard.com/) if you can't.
0
 
LVL 2

Author Comment

by:johnny99
ID: 1540524
Thanks for reassuring me about my sanity at least -- what do you do?

Personally I just save, switch to the Finder, and look there: is that logical?

Or is the rule of thumb of roughly a half close enough?

My life is made harder at work by an NT server which tells Macs bizarre file sizes. Even the smallest GIF takes up over two gigabytes according to NT!


0
 
LVL 3

Expert Comment

by:rickyr
ID: 1540525
Hiya...

There is also another factor to be considered, and thats the files size in the finder is dependant on the size of the drive. Especially for small files. this is because, due to the way disk space is allocated, If you have a big disc (2gig say), your smallest file size would be multiples of 64K. For a 300 meg disc the file size will be in multiples of 8K. This would mean that a 16K file on a small disk, would grow to occupy 128K once moved to your hard drive. This has become even more apparent to you because you are trying to get your files as small as poss for the net.

try this....
copy a floppy full to the brim with files of 8K to your hard drive. then copy them back to the same floppy, If you use a 1-2gig drive for this experiment, you will find that there is not enough room on the floppy to copy them back again.

regards
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Yesterday Apple introduced their revolutionary new iOS 5 operating system that claims to be the ultimate mobile technology interface. One of the biggest innovations of the new operating system is the introduction of the iCloud computing network. Thi…
There is a security feature on iOS devices that is nearly impenetrable when it has been activated.  This article will provide some possible solutions as well as necessary steps to take to ensure you do not end up with a locked device.
Users will learn how to set proper sequence settings, scale images, paste attributes, add transitions, fades, and music. Open up Final Cut Pro 7 and Create a new Project: Set the Sequence Settings. a) Click File > Easy Setup > Format > Apple ProRe…
CodeTwo Sync for iCloud (http://www.codetwo.com/sync-for-icloud?sts=6554) automatically synchronizes your Outlook 2016, 2013, 2010 or 2007 folders with iCloud folders available via iCloud Control Panel. This lets you automatically sync them with…

895 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

15 Experts available now in Live!

Get 1:1 Help Now