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Re: [OM] THANKS new web site

Subject: Re: [OM] THANKS new web site
From: Michael Kopp <mkopp@xxxxxxxxxx>
Date: Sun, 23 Feb 2003 22:45:10 +1300
At 9:11 -0800 22/2/03, Soegi Hartono wrote:

http://www.truimpression.com

>Thanks to all who make sugestion on my new website (www.truimpression.com),
>I made change, I resize the image (about 65maller), but I have not done
>the thumbnail and all sugested issues, kind of still scratching my head.
>
>anyway once again thanks (more sugestion also welcome)

Soegi,

You've made the images smaller, and that's good because they can be seen in
one screen without having a gigantic monitor or having to scroll a lot.

But you still have a problem with the file size of the pics.

C.H.Ling pointed to it:

>I'm not sure if you are intentionally did it, the size of the images are
>actually over 1500lines at the long end. The size are "compressed" by the
>HTML code, it doesn't make the picture smaller in file size but smaller
>during display only.

To explain a bit further, I think what C.H. means is that you have resized
the _display_ dimensions in whatever program you're using to make the Web
pages, but the _actual_ picture dimensions haven't changed, which means
that the file size is still huge (over 500 KB on some) which means a slow
download and progressive display that is annoying. On my fast ADSL
connection, the big night panorama of the boat basin in front of the
skyline, and the snow scenes, still took over 15 seconds to load in my
browser window, painting lines downward as it went.

As another person wrote, all that extra information is wasted on the Web,
because the picture displays at monitor resolution, which is 75-90 pixels
per inch no matter what the monitor is set at (higher monitor resolutions
only squeeze the pixels ...).

The comment of another person, that some of the pictures had jaggies, was
not seen by me, and I'd be surprised if any of these huge files had that
problem, which would be indicative of the original images being at too low
a resolution. But with those huge file sizes, a low resolution scan would
be several feet wide. In digital photography and reproduction, pixels equal
size. More pixels, bigger size. But, again, a monitor displays only 72-90
per inch (depending on whether it's Mac or PC), so it doesn't make any
difference.

You don't say anything about your software, hardware or techniques.

We presume that these are film images that have been scanned at high
resolution, mainly for high-quality reproduction. They could be digital
images, in which case the following discussion can be skipped down to the
paragraph headed "Digital images".

So that translates to lots and lots of pixels. A 300 dpi scan of a 35mm
frame in colour made with a scanner that has an optical resolution of, say,
1200 pixels per inch, at a magnification ratio of, say, 800 percent, to get
an image size of about 7X10 inches (17.5X25 cm) yields a file that is about
35-40 megabytes of data.

You've obviously either reduced your settings while making the original
scans, and saved them as original JPEGSs, or converted original scans in
some other format to JPEGs afterwards. Either way, you're still sending
huge files across the Net that don't translate to higher quality.

And, if you're saving the original scans as JPEGs straighaway, you're
actually losing quality, because JPEG is a "lossy" format. This means that
manipulating the image after saving it as a JPEG produces successively
lower quality.

You should be saving the scans as TIFFs, or, alternatively, PhotoShop
native file format, so you can do any manipulation (and I'm talking about
even simple things like sharpening and curve control and size manipulation,
not fancy stuff) and save the result in another format, such as JPEG, for
archiving, transmittal, and Web display. You should also keep the raw scan
as an archive file before any changes are made. Either make a simple file
dupe of the original scan and work on that, or, in PhotoShop, for instance,
use Save As, or, preferably, Save a Copy, so you can revert to the
unmanipulated image size and quality by using the History, and make other
attempts.

For the Web, the bottom line is that you need to make, as someone said,
files whose specifications are no more than 600 pixels in any dimension,
and, for thumbnails for an index page, no more than 125 to 150 pixels. I
prefer nothing larger than 450-500 pixels in any dimension so that even
people with their monitors set for 640X480 resolution can see a full
vertical image in one screen without scrolling.

And, in the process of making smaller dimensioned JPEG copies of your raw
scan files for the Web, you will also want to reduce the resolution,
because the excess resolution of the images you are posting now is wasted
and slows downloading.

So, in PhotoShop, for instance (but in Graphic Converter for the Mac, or
any other image manipulation program), when you make your copies for the
Web, the first thing to do is change the resolution from the higher value
of the raw scans to a resolution closer to that of computer monitors. Most
Web folks will set their image resolution somewhere between 70 and 150
pixels per inch. If you do this first in PhotoShop, for instance, in the
Image Size command dialog box, you will see that the image size in pixels,
and the "print size" will change as well. But it still may not be near the
size you want for display pages or thumbnails. So now you change the larger
dimension figure to the size you want for the Web -- either the 500 or so
pixels for display or the 125 or so pixels for thumbnails.

These are the images you will use in creating your Web pages, and which you
will load to your Web server.

Now, if you're using a Web-based Web site template service from some Web
server, and not building your pages yourself on your own computer and
uploading them to the server, the process is still the same: use the
smaller sized images.

Digital images.

The process is much the same, except that you have a fixed image size and
file format and file size depending on the specifications and settings of
your camera, and its output file type. If the images you're showing on your
Web site are digital images, and you have set your camera for its maximum
resolution and highest quality file, that's fine -- you just run those
images through PhotoShop or other image manipulation program in the same
way as described above for scans. Your camera may have come with image
capture and manipulation software for your computer, and that is capable of
doing the same process, although the method will be different.

There are lots of digital image sites on the Web to help you; a good place
to start might be http://www.imaging-resource.com/. Just make sure you
explore all the links to get past the product reviews and chat down to the
explanation pages, like this one
http://www.imaging-resource.com/TIPS/PRINT1/PRINT1A.HTM, "Pixels, Dots, and
Inches: How Big Can I Print It?".


Hope this all helps.

-- 
Cheers from Godzone,

Michael Kopp
Wellington, New Zealand

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