Basic Editing

Resizing a digital photo

Written by Gail Bjork

Learn how to resize and reduce the file size of an image before sending it by email or displaying it on a web page, online gallery or auction site.

resize-optimized

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 size becomes can be greatly reduced.

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

Image resize dialogueMore 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

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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.


About the author

Gail Bjork

Gail Bjork, who is passionate about digital photography, is the owner and editor of Digicamhelp.Gail is the author of three illustrated ebooks about digital photography. A number of her photos and digital photography related articles appear at other websites.In 2006, a series of her photos, People in the Louvre, were exhibited at the Underground Photo Gallery
in Iisalmi Finland. Eight of her photos taken in the Florida scrub are on permanent exhibition at Parrish Medical Center in Titusville, Florida.Gail served twelve years as an elected member of The School Board of Palm Beach County, Florida, one of the largest school districts in the U.S. She has also been the editor of a small town newspaper and a free-lance writer. Gail and her husband owned and ran several small businesses.

7 Comments

  • I would not be bothered about these jokers… It is not about true beginners or not… it is about taking the time to figure things out… either from a little research or basic common sense.

    “constraint proportions” – Keep proportions fixed (Obviously, this is a reference to scalability – or didn’t you do primary school maths?)

    “Aspect ratio” – Aspect – refers to a property, quality or appearance. Quite obvious which one that means if you are brought here when you tried to find how to resize a photo isn’t it? Ratio – again.. please refer to primary school maths. This then obviously translates to the dimension ratios of a 2D object, the image in this case.

    Don’t disturb the poster just because you are ignorant.

  • Austin, sorry you find this article difficult. We make every effort to make things as simple as possible. I realize, though, that not all photo editing software is easy to use. If you let me know what software you’re using perhaps I can be of more help. Also, check the software help files.

  • I am a student at woodcreek high school and I’d just like to say that although this site serves the purpose it needs to for fairly tech savy people. it needs a little bit more clarification for people who truely dont understand the concept of how compters or more specificly how computer image file types and sizes function

  • Liz, I’m sorry you found it useless. Others don’t but maybe some of the information is obviously not clear enough for “true beginners.” Your points are well taken and links have been added to other articles where such things as “aspect ratio” are explained. I hope you find them helpful and, if not, let us know and we will attempt to make the concepts even clearer.

  • This is absolutely useless – clear as mud.  When are you tech people going to learn how to communicate with true beginners!! “when contraint proportions remain selected,the image will retain its aspect ratio”   What does that mean!!