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If you produce high-quality images (e.g. by means of a raw conversion workflow), you may find that they are unsuitable for e-mailing or display on the web as JPEGs in their present form. They may be of a large dimension, high-resolution (e.g. 300 dpi), high bit-depth (i.e. 16 bits/ channel), with an unsafe colour profile (e.g. ProPhoto), not enough compression, and be a bit fuzzy after re-sizing. You could open each individual image that you want to re-purpose in Photoshop and change the pixel dimensions, the resolution (to 72 dpi), the bit depth (to 8 bits), the colour space (to sRGB), the quality (e.g. to 8 cf. 12), and apply sharpening. But there is a much easier way using Photoshop Actions and Automator...

Generic automation

The Fotogenetic Photoshop Actions by Alex Mabini automate the above processes.

Stop reading here—unless you have Mac OS X Tiger. Under Tiger Mabini's "Save for Web" Action can be combined with the "Do Action" (and other) Photoshop Automator Actions by Ben Long (available here):

The resulting Automator workflow can be saved as a Finder plug-in so that it is available whenever you right-click on an image in the Finder:

Alternatively, it can be saved as a stand-alone application that sits on your Desktop (or in your OS X Dock) onto which you can drop one or more files:

It really works!

What about iPhoto?

iPhoto includes an "Email" button. Let's throw a 34.5 MB TIFF at it (16 bits/ channel, 300 dpi, 3008 x 2000 pixels, ProPhoto colour space). clearly, not something you would care to e-mail on the basis of file size alone! I choose to resize to Medium:

This produced a (better than estimated) 72 KB JPEG, 8 bits/ channel, still 300 dpi, 640 x 425 pixels, still in the ProPhoto colour space). Quick and easy, but 300 dpi when 72 dpi will do, and not as "safe" for display as the sRGB colour space. The "Web Page" export function of iPhoto produces an image with the same characteristics as the e-mail function:

What about ImageReady CS2?

What if we open our TIFF in ImageReady, resize to 640 pixels width, in the Optimise palette select JPEG format (Preserve ICC Profile is unchecked by default), then Save Optimised?

We get a pleasing file size (a 28 KB JPEG), 8 bits/ channel, 72 dpi, 640 x 426 pixels, and no colour space—but the colour is "wrong" next to the original (in ProPhoto) or the image as processed by Mabini's Action (conversion to sRGB), and it looks comparatively soft. The following .png graphic shows the result of re-purposing with ImageReady (top) vs. via Mabini's Photoshop Action (bottom):

Why convert to sRGB?

For the simple reason that the image will have a more predictable look on a system that isn't colour-managed. Think of sRGB (in full, sRGB IEC-61966-2.1) as the lowest common denominator: the colour range (gamut) it describes should be universally known to all digital cameras, scanners, computer monitors, and printers. The compromise is that the gamut is too small to contain all the colours your camera can capture or your printer can print, so it's really only suitable for e-mailing or web display of snapshots. If you want to provide someone with an image destined for print, you should ideally be working in a larger colour space like Adobe RGB (1998). More on colour spaces here.

Credit: Thanks to José Salcedo (website) for his valuable advice on the need for re-purposing and rationale behind some of the above settings.

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