File sizes

[BlueDiamond]

If I do some bitmap editing using Corel and want to send the image as an email attachment, I save (export actually) the file as a JPEG to "My Documents" or whatever. Then, I open my email programme, write the text, attach the file and send. Some of the attachments turn out to be really large though and take my old steam-driven computer ages to actually send.

What is a good way of reducing the size of the attachment? Save it as a JPEG, GIF, TIF ... is there any difference between these? Does physically reducing the size of the image (scaling) make any difference to the resulting file size?

[flynverted]

WinZip

[BOAC]

A jpg can be reduced in size quite significantly without loosing definition - the prog I use is Fireworks by Macromedia, but there may be plenty of free progs that will do it. Here is one I found via Google that may be worth a look - haven't checked it myself. Appears to do other formats also.

Whoops!- just noticed it is a big file itself. Have a browse around Google?

[Jhieminga]

Bluey, have a look at the settings in Corel. JPEG files are always compressed when they are saved, and playing with these compression settings will probably get you the result you want. I haven't used Corel in ages, but somewhere in the software, either in the 'settings', 'options' or 'preferences' (or whatever they're called) dialog, or in the 'export' dialog (might be under a 'more options' button) there will be a 'JPEG compression' or 'JPEG Quality' setting. On a scale of 1-100% I find that somewhere between 45 and 75% will get you a decent tradeoff of quality against filesize. Something else that might help is to reduce the image size before saving, unless you need a large size image many people will not be able to display an image over 1000 pixels wide at full size setting anyway.

Winzip won't help you since a JPEG file is already compressed. The only usefullness of Winzip in situations like this is to bundle several images in one file. The filesize will not change by more than 2% though!

As for image types, JPEG is the way to go for e-mailing purposes. GIF is better suited to logos and digital images which use large areas of a single colour. TIFF is a file format that can store a lot of information (layers, pen paths etc), and is therefore not suitable for e-mailing since TIFF files can get quite large.

[flynverted]

Winzip won't help you since a JPEG file is already compressed. The only usefullness of Winzip in situations like this is to bundle several images in one file. The filesize will not change by more than 2% though!


Jhieminga
Forgot that, haven't used winzip in ages.


Been using Winrar
the past few years. It'll compress up to 50%

[Jhieminga]

It'll compress up to 50%

Not JPEGs though!!

(Actually, since I'm not a big WinRAR user, I wasn't totally sure and had to check.)


You can see here that WinRAR performs the same as WinZip on JPEGs. It will save you a few bytes (probably on the header and EXIF info in the file) but there is no substantial filesize change.

[flynverted]

Never tried compressing jpegs, just hex and bin files. Compressed them 50+% Disregard my previous posts .

[Conan the Librarian]

jpgs are in their nature, a compressed and lossy filetype. Thing is that for most purposes, they are fairly ok for pictures and in many programs, you can alter the amount of compression, (read quality) to suit.

Changing the size of the pic will also reduce filesize, but to give a comparison, I have jpogs of up to 7 MB from my trusty Nikon, but with a bit of fiddling can have something that will suit most people weighing in at around 150KB

I suppose what would be really useful now, is some clue as to a wonderful, full featured and intuitive package that costs bugga all.

IRFANVIEW!


Conan

[flynverted]

One has IRFanView, Mr. Conan, but seldom use it. I prefer PhotoPlus6
For photo editing.

[BlueDiamond]

Thanks everyone. I've already applied as much compression as possible without loss of quality and the files were still 4-5Mb each. I experimented a little and found that physically reducing the image size (they're VERY big!) made a lot of difference, and brought the file size down to 25% of what it was.

Thanks especially for that comparison on file types, Jhieminga, that was very useful.

Thanks again, Bluey.

[Gouabafla]

I add my vote of support to the Irfanview users. I use a variety of software to produce and edit graphics, but when it comes to resizing files for posting them on the web or emailing them, Irfanview can't be beat for speed or convenience (and its free).