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Old Apr 18, 2005, 11:51 AM   #1
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Hi,

I've just read a helpful post by Slipe describing how to resize on Irfanview, but I can't work out how to downsize enough for emails (ie under 100k). Even with the image downsized to 600x 450 pixels, the files size seems pretty big.

I've downloaded the plug-ins, so can access the email facility, but I still can't see how to get the files small enough. :roll:

Advice would be much appreciated.

Best wishes,

Canna.
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Old Apr 18, 2005, 12:29 PM   #2
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In addition to the resolution of the image, jpeg quality also impacts the file size. Higher Compression = Lower Quality = Smaller Filesize (but don't decrease quality any more than needed for the file sizes desired).

Irfanview allows you to control the amount of jpeg compression applied via a quality slider.

If you're resizing one image at a time, you'll see the ability control jpeg quality when you use the "File, Save As" menu choice.

If you're using batch mode, you'll see an Options button next to the Ouput Format that brings up the JPEG Quality slider. I've got a screen print that shows it in this thread:

http://www.stevesforums.com/forums/v...mp;forum_id=70


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Old Apr 19, 2005, 2:25 AM   #3
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Jim,

Many thanks for your help & the link.

One thing though, I don't see how, when you are reducing the quality of a pic, you can see the actual level of reduction in file size. Maybe you just do it arithmetically? Half the quality =half the file size?

I'm actually checking this out for a friend - in PSE2 I can see veryprecisely the correlation between quality reduction and file size reduction. Maybe with Irfanview you just do it in your head?

Sorry to keep pestering! :roll:

Canna
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Old Apr 19, 2005, 6:17 AM   #4
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Canna, there is no way to predict the resulting file size of an image, until it's actually processed. A JPEG image with more detail/colors will not compress as much as a JPEG Image with less detail.

So, you'll have to experiment.

I would not decrease the quality any more than necessary for the desired results.

P.S.

I VERY rarely e-mail an image. If I have an image that I want someone to see, I'll upload it to an album on a web site. Then, I'll just send them a link to the image so that they can view it at the desiredsize.

I use http://www.pbase.com for this purpose. It automatically creates multiple viewing sizes when you upload a larger image (small, medium, large, original).


For example, here is the "large" viewing size for an image in an album (around 72kb):

http://www.pbase.com/jcockfield/image/19295358/large

Here is the "original" size I uploaded (around 1.8mb):

http://www.pbase.com/jcockfield/image/19295358/original


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Old Apr 19, 2005, 7:56 AM   #5
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Wow - I've never looked at an image that size on screen before! :O Big difference (big positive difference!) Nice to see so much detail.

Thank you also for the idea of a website.... Probably farbetter for people to be able to look at pix at their leisure, rather than being lumbered with big emails when they're in a hurry.

All best wishes,

Canna.
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Old Apr 21, 2005, 10:32 AM   #6
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Canna, you can use the "Save for Web" featurein Elements 2, under the FILE menu, and it will not only tell you the resulting file size, but give you a before & after preview of the image.

Hope this helps, Lou
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Old Apr 21, 2005, 12:18 PM   #7
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Irfanview defaults to 80 quality – at least in the version I have. With ALL of the boxes unchecked in the save dialog it is very hard to get a 600 X 450 JPG over 100k at 80 quality.

There isn't a mathematical relationship between save quality and file size. A quality 80 image is well less than half the size of the same image saved at quality 100. It is 1/3 to 1/4 the size of a quality 100 for most images saved from Irfanview.

As you lower the compression quality you increase the size difference between individual files. Quality 80 is a good compromise between quality and size. By the time you get to quality 50 skies are terrible.

There are free online storage sites that will make prints for anyone who wants to order one. The price is usually pretty good as is the quality if the images are sent to the site in a good size and quality to start with. Good quality for a 4 X 6 print would be about 1200 X 800 at 80 quality as a minimum target.

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Old Apr 22, 2005, 2:01 AM   #8
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I can't tell how helpful all of this has been - for me as well as my friend.

In fact she has just had a baby, so I think she will have to get PSE - and then upload the young hunkregularly onto a host site for her pals to enjoy. It seems the simplest.

Huge thanks again for the help. I love the way you can learn piecemeal through forum help like this.

Canna.
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