Digital Photography Hacks [Electronic resources] نسخه متنی

Hack 64 Sample Down for Email Attachments

Your high-resolution photos are perfect for
printing but not so good for sending to Aunt Betty, who has AOL
dial-up. Have mercy on Betty and learn to sample down.

We've all been there before: someone in the
family gets a brand-new mega-megapixel camera, and the next thing you
know, you have a slew of emails with 1 MB attachments. Your only
salvation is to hope that Photoshop Elements came bundled with the
new camera, so you can explain how to sample down those images for
more reasonable email attachments.

I'll start with a 3.2-megapixel image shot at the
highest resolution and quality settings on the camera. Its compressed
file size on my computer is 1.5 MBtoo big for sharing via
email but nice for making an 8" 10" print.

To sample it down for publishing on the Web or sending via email,
open it in Photoshop and choose the Image Size command
(ImageResizeImage Size in Photoshop Elements;
ImageImage Size in Photoshop CS).

As shown in Figure 6-4, the dimensions for the
picture are 2048 1536 pixels at 72 ppi. That's way
too big to share online. Generally speaking, you want to sample down
the image to 400 300 or 640 480 for attachments.

Figure 6-4. A full-size 3.2-megapixel image, too big for email attachments

To change these dimensions, make sure the
Constrain Proportions and
Resample
Image boxes are checked and then change the Width dimension to 640,
as shown in Figure 6-5. Notice how the Height
setting automatically changed to 480? That's because
you had the Constrain Proportions box checked. Click OK.

Figure 6-5. The resized image, much more portable

I almost always sharpen an image a little after sampling down; for
some reason, it seems to lose a little edge in the process. From the
Filter menu, select SharpenUnsharp Mask. Change the Amount
setting to 12% and leave the Radius setting at 1.0 pixels. The
Threshold can stay at 0. Click OK and examine the picture. If it
needs another round, apply the same settings again. Your photo should
now look crisp and clean.

Select FileSave As and give your picture a new name. You
might want to add lorez or
email to the title to help you remember that
it's been sampled down. Keep your master safe and
sound at full resolution so that you can make beautiful 8" 10" prints
when those requests come rolling in.

A second dialog box will appear, asking you to set the Image and
Format options. I recommend a quality of 8 and Baseline Optimized,
respectively, for these settings. Your picture will still have lots
of quality but a much more reasonable file size. Click OK.

The new 640 480 version of the image is only 155 KB in size.
That's quite a reduction from the 1.5 MB size of the
original file. Plus, when your adoring audience opens the picture on
their computers, it won't take over their entire
screen.

There you have it: better family relations through sampling down.