Processing
Digital Images for Web Presentation
Text copyright Greg Downing, all rights reserved
Having
your images online can help you reach worldwide audiences, whether for
the sole purpose of sharing your photos for enjoyment or as a marketing
tool for your growing business of nature photography. Participation in
an online nature photography community, such as NatureScapes.Net, provides
opportunities to post your photos for critique and receive valuable feedback
from objective viewers of varying experience levels.
But being faced with exhibiting your images to an online audience for
the first time can be nerve-wracking for some. Is the image sized right?
Are the colors off? Is it sharp enough, or is it oversharpened? Work to
fulfill our photographic vision continues in the digital darkroom and
we all want our work to look its best. What are the steps for preparing
an image for display on the World Wide Web?
Similar
to preparing images for printing, web images require the same tonal adjustments
and color correcting, but in the final steps of processing there are different
considerations. Each step in the process of preparing a photo for the
web is tailored for that particular image, but a basic workflow can be
established. The more proficient a photographer becomes with individual
tools used in the workflow process, the better the results. Workflows
by individuals may vary substantially, but here are some of the basics
to get you started. This article is not intended to be a comprehensive
workflow for processing your images but rather more of an overview of
the basic adjustments often necessary.
THE
DIGITAL FILE
The master file is your original image, whether JPEG right out of a digital
camera, a camera’s RAW file converted to editable TIFF or JPEG format,
or a slide or negative scan. The resolution of this master file will vary
depending on the camera or scanning device and the settings used.
A
digital SLR shooter capturing RAW images can either convert those RAW
images to editable TIFF files or, if the option is available, use a dual-capture
JPEG which is sometimes a separate file or an embedded JPEG which can
be extracted. There is less latitude with certain adjustments starting
with a JPEG, but sometimes skipping the RAW conversion process can be
more convenient and is often adequate for a web-sized image. Since TIFF
is a lossless format and JPEG is not, photographers shooting in JPEG mode,
or using the extracted JPEG from a RAW file, should immediately save their
images as TIFF files as a first step in their workflow process. This will
prevent any degradation to the image as it is processed and re-saved.
Personally,
I prefer to shoot in RAW mode and to process the RAW image into a converted
TIFF file using my favorite RAW conversion program, BreezeBrowser (www.breezesys.com)
with further processing to be performed in PhotoShop. I also prefer to
work on all my files in 16 bit mode in order to ensure I am working with
the largest possible amount of tonal information which results in smoother
color gradation and to prevent posterization. (Note that most submission
requirements ask for 8 bit; a conversion can be performed when processing
is complete.)
Film
shooters can scan their images and save them as 16 bit TIFF files. I recommend
scanning at the full resolution capability of the scanner and saving a
master file first.
COLOR SPACE
Working with your master files in a wide-gamut color space means you will
have a wider range of colors available. All my RAW files are converted
to TIFF with the Adobe 1998 color space where they stay until an end use
specifically requiring a different space. Note that Adobe 1998 is also
the preferred color space for most digital printers and stock agencies.
Digital
cameras set to capture JPEGs or TIFFs should be sure their cameras are
set to shoot in the Adobe1998 (also sometimes referred to as Adobe RGB)
color space. There are some color spaces that are wider than Adobe1998
but are often of little benefit since most output devices are unable to
render them.
Images
to be placed on the web ultimately need to be converted to a different
color space upon finalizing the edit process; this is covered later under
“Convert profile.”
LAYERS
I prefer to make all tonal and color adjustments using adjustment layers.
This allows me to save my adjustments while still affording me the ability
to open the file and change, or even completely undo, any adjustments
I have made to the original.
CLEAN-UP
In a systematic checkerboard pattern I examine the entire image, viewed
at 100%, looking for dust spots and removing them using the healing brush
with a brush size slightly larger than each spot. The clone tool can also
be used but my personal preference is the healing brush, which is new
to PhotoShop CS. I do all dust spotting on a duplicate layer on my original
file in case I make a mistake.
BASIC
ADJUSTMENTS
The basic tonal and color adjustments required for a given image can vary
greatly from one to another. Most images require some levels adjustments
in order to increase dynamic range and adjust contrast and color. This
can be done with simple levels adjustment layer or a more targeted curves
adjustment. Darker areas in a frame that lack detail might be recoverable
using curves, masks or the Shadow/Highlight tool. See
the NatureScapes.Net article on Photoshop’s Shadow/Highlight tool.
Elements
in the frame that should appear neutral can be sampled for color casts
using the info palette and the color sampler tool. A higher RGB value
of one color over the others indicates a cast in the higher area. A warm
glow from early or late light can be an agreeable cast, but often casts
with green or blue are not appealing and may be removed using various
methods.
In
flat light photo contrast may be lacking; in harsher light contrast might
be too high. Color saturation might also need to be reduced or added to
create a more lifelike, realistic image. This is particularly true of
digital images as they lack the saturation and contrast desired by many
nature shooters, especially those fond of highly saturated film emulsions.
SAVE AGAIN!
After I am satisfied with the major tonal and color adjustments to the
image, I will save the file as my “adjusted” master file.
The file is saved in the TIFF format with all adjustment layers intact
- still in 16 bit mode. At this point, if the “original” is
a converted RAW file with no adjustments, it is discarded and replaced
with my adjusted master file.
At
this step any adjustments that are unique to web presentation take place
on a duplicate image.
CROPPING
Cropping an image can often help increase the subject size for better
web presentation, since the photo is so small on the web to begin with.
Due to the relatively small size required for web photos, it is sometimes
tempting to crop an image significantly. If you are sharing your photos
just for the enjoyment of it, there is nothing wrong with this. However,
if you are in the business of selling photos, in print or for stock, web-use
only photos have little market value and can appear deceptive relative
to your actual, useable portfolio.
Tip:
Select the entire image with the crop tool and hold the Shift key down
while using the mouse to drag a corner – this will maintain the
same aspect ratio of the original file.
RESIZING
Possibly one of the least understood aspects of displaying images in electronic
format is resizing them properly. Unlike printed output, the only numbers
that matter for web presentation are the actual pixel dimensions. When
looking at the image size dialog, output size and resolution can be ignored
and are only applicable for print output. An image that is 72 pixels per
inch (PPI) and 600 pixels wide is exactly the same as one that is 300
PPI and 600 pixels wide and will look the same when displayed on your
monitor. Note: The PPI settings do matter when using text. If you have
an action to add your copyright, using the same PPI for each image will
produce the most consistent results.
SHARPENING
Following all other adjustments the image is ready for final sharpening.
This important step is often made more critical from downsizing, which
results in some loss of sharpness. Sharpening through Photoshop’s
“Unsharp Mask" filter (USM) will help correct this.
When
sharpening small images without a lot of pixels, such as those for the
web, it is best to choose a low radius to minimize sharpening “halos.”
My own settings typically do not use a radius higher than .02 or .03,
with the amount varying from 100-500%. Often there are areas in an image
that require more sharpening than others, in which case, I sharpen in
targeted areas. See
Tim Grey's article at NatureScapes.Net for details on sharpening.
COPYRIGHT
When placing photos on the web, it is good to consider marking them so
the copyright owner is known. The word “Copyright” or symbol
“©” followed by the copyright owner’s name is adequate.
Done properly, its impact to viewers enjoying the image can be negligible,
while at the same time making the photo less appealing for misuse. Transparent
watermarks are also easy to do in Photoshop and typically consist of the
copyright symbol “©” or a personalized graphic. Find
out more about copyrights in Carolyn Wright’s NatureScapes.Net article.
CONVERT
PROFILE
One of the last steps during the image editing process for web display
should be to convert photos to the sRGB color space. While most web browsers
do not recognize color profiles, sRGB is designed for the "typical"
monitor, so it's the most appropriate for electronic distribution. Images
left in the Adobe 1998 color space will lack color intensity and saturation
when viewed on the web.
Tip:
Switch your color space in Photoshop to "Monitor RGB" just before
your final adjustments are made and you will see the image exactly as
it will appear on the Web to your own monitor.
There
are variations between every monitor, even when properly calibrated, so
viewers of the same image will see slightly different color and brightness.
Even sharpness may vary, so keep that in mind. If you have access to multiple
monitors, it can be revealing to preview your images on each.
SAVE
FOR WEB
The latest versions of PhotoShop include a save option specifically for
web output called "Save for Web." This convenient tool under
the File menu allows some options important for web photos. Color shifts
noticed in the preview pane may indicate the color profile was not changed
to sRGB.
When
the Save for Web dialog opens, select “JPEG” as the file type.
Selecting “Progressive” means the image will start to show
from the top and move downward while opening in browsers, instead of no
image showing until the entire photo appears. Selecting “ICC Profile”
attaches the sRGB profile to the photo. While this is not a necessary
step, in most cases it is still recommended in case a viewer is using
a program that recognizes color profiles. Using the small arrow button
towards the upper right part of the screen allows optimization of the
file; by entering the desired file size and clicking “OK”
the program will adjust the quality settings to ensure a file of those
specifications. Using “Save for Web” also removes the EXIF
data, reducing the overall file size.
With
the final version saved, the image processing part is complete and the
photo is ready to display! To show up in places like image critique forums,
that file must first be hosted by a web server. It can be uploaded to
a personal website server and often may be posted to bulletin boards.
If a personal website is not available, NatureScapes.Net membership provides
an image upload service for easy and convenient upload for hosting on
the server to post in NatureScapes.Net's image forums. Hope to see you
there!

Greg Downing is a professional nature photographer specializing in birds.
His images are known to many for their attention to detail and precise
compositions. He has been published worldwide and owns and operates a
successful photographic workshop and tour business, teaching bird photography,
digital imaging and Photoshop techniques. He is also the founder and publisher
of NatureScapes.Net. For more information, visit Greg’s personal
website at www.gdphotography.com.
Feel
free to send your comments on this article to the
at NatureScapes.Net.

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