Note that I used Adobe Photoshop CS2 to outline the steps. If you use another image editing program such as PaintShopPro, The Gimp, or an older version of Photoshop, the menu selections may not match what you see here, but there should be similar functions in your chosen image editing program to duplicate this functionality.

Also note that this outlines just the basic steps and does not get into more advanced topics such as color space/color profile conversions (ex. Adobe RGB-->sRGB).

This tutorial assumes that you have already completed all of your normal post processing and you are at the point where you are ready to submit the photo to PhotoSIG.

That said, off we go....

First, make sure your photo is in RGB mode. Even if you converted your photo to black and white or grayscale, in order to properly display on PhotoSIG it has to be an RGB image. From the menu, simply select Image-->Mode-->RGB color. (This will not change a black and white photo to color--it is simply a tag that is attached to the jpg).

The next step is to resize your presumably large image (most likely 6 megapixels or more) to fewer than 640,000 pixels.

From the menu, select Image-->Image Size

In the dialog box that pops up, you'll notice numbers in the "Width" and "Height" boxes in the "Pixel Dimensions" box at the top. These are the numbers we will be concerned with. For this tutorial, you can safely ignore the numbers in the "Document Size" boxes, including the resolution setting. We are only concerned about the total number of pixels.

In the box above, you'll see that this image is 3028x2212 pixels. Multiplying that out, we can calculate that this image is about 6,700,000 pixels (6.7 megapixels) in size.

The next step is to reduce that to fewer than 640,000. Simply enter "600" in the box representing the longest side (replacing the 3028 in this example), and the other side will resize accordingly. You want to keep "Constrain Proportions" checked, and make sure "Bicubic" resampling is selected.

In general, a pixel value of between 600 and 800 for the longest side will give you a properly sized image for PhotoSIG. In this example, my resized image is 600x438 (262,800 pixels)--well within the 640,000 pixel limit.

After resizing, you may notice that your photo appears small on the screen. This is because Photoshop remembers your last "zoom" setting for the image, and displays the resized photo at the previous zoom setting. While working with large images, I usually have my zoom set at 25% in order to get the whole photograph on screen. After resizing, you'll want to view the photo at normal resolution (100%), or as Photoshop terms it, "Actual Pixels". Simply click the magnifying glass on the tool pallet, right click the image, and select "Actual Pixels".

Now, the very important step that many people new to digital post processing miss!

After such a drastic resizing (we went from 6.7 million pixels down to about 260,000--a loss of 96% of the image!), the image will appear soft. It will lack the tack-sharpness of the original (assuming, of course, that your original was ever tack sharp to begin with). In order to restore sharpness, you need to apply some sharpening using your image editor. For this tutorial I will use Unsharp Mask, but there are a number of different ways that you can sharpen. So, from the menu bar, select Filter-->Sharpen-->Unsharp Mask

In the dialog box, we will be inputting values for Amount, Radius, and Threshhold. There is no "correct" setting here, and the right amount of sharpening will depend on the size of your image as well as how much detail is in the photograph. Feel free to experiment and find out what works for your particular image. A good starting point that I find works well for many different photos at this size is 150, 0.4, 0.

Once sharpening is applied, we have a completed photo--resized and sharpened--ready for saving!

Photoshop provides an easy way to save an image for display on the web, with good control over jpg compression and final file size. From the menu bar, select File-->Save For Web.

The top right part of the dialog box provides control over jpg compression--this is the "Quality" slider, and I find that a setting of 70 or 80 provides plenty of image quality (not a lot of compression), while giving a file size small enough for web display.

The bottom left portion of the "Save For Web" box will show the file size at the selected Quality setting.

In the example above, using a Quality setting of 70, I will have a file size of 59k--again, well within the limit of 360k for PhotoSIG.

Click "Save", and you have a completed, optimized file ready to upload!

Getting Along With other photoSIG Members
Guide To Critiquing Photographs
Guide To Using HTML In Your Posts
How to Create a Journal Entry
How to Create and Manage Your Portfolio
Resizing Photos to meet photoSIG's Guidelines
Resolving Problems