Click for larger view

A digital image can look huge when viewed on a computer monitor. Not only that but its file size is usually very large. When an image is reduced in size, its file size becomes much smaller too.

Resize an image before sending it by email or when planning to display it on a web page, online gallery or auction site. One rule of thumb is to resize it to fit within a normal browser window so site visitors won’t have to scroll to see the entire photo.

All image editing programs include resizing tools. Most are straightforward, easy to use and take much of the guesswork out of resizing and compressing images.

Reducing the size of a digital image

More advanced photo editing programs let you select the compression level so the visual quality of an image doesn’t look degraded. The tutorial below is illustrated with Photoshop.

The original image used for this illustration was 2592×1944 pixels with a file size of 14.4MB! Try sending that one via email!

After resizing the image to 600 X 450 pixels, the size was reduced to 791K. When it was saved for web at a quality setting of 70, the final size went to 75.25K! The image still looks good and those opening it will appreciate your efforts.

Image resizing steps

1. Image Menu > Image Size
   When the image size window opens, change the resolution to 72 if necessary. It is important to do this first.
2. Next, change the pixel width dimension to 600. It is not necessary to change other settings. When constrain proportions remain selected, the image will retain its aspect ratio. Also make sure resample image is ticked.
3. Click on the OK button.

Final touches

Click on image for larger view. Look closely at how the image degrades as it is given a higher level of compress.

Almost all images need sharpening when reduced in size. Filter menu > Sharpen > Select the appropriate sharpening command.

Save your work: File menu > Save for the Web.

It is at this step in the process that you’ll be able to set the compression level of the image and watch the effects in the window.