How To Resize Large Photos in OS X with GIMP - InformationWeek
Infrastructure // PC & Servers
11:58 PM
[Dark Reading Crash Course] Finding & Fixing Application Security Vulnerabilitie
Sep 14, 2017
Hear from a top applications security expert as he discusses key practices for scanning and securi ...Read More>>

How To Resize Large Photos in OS X with GIMP

Here's how to use GIMP in OS X to resize images.

As digital cameras continue to produce improved shots -- and as the number of megapixels increases exponentially -- file size quickly gets out of control.

Here's how to use the free GIMP program for OS X to resize your huge images. That way, you can more easily share them and just generally deal.

First, download and install GIMP for OS X.

Now launch GIMP and locate the image you want to resize. For this example, I've chosen Flowers in Seoul.JPG, a photo that resides on my desktop. Right-click on the image and select Open With >> Gimp.

When the Convert to RGB working space dialog box appears, click Convert.

In the main GIMP window, select Image >> Scale Image.

The Scale Image window will appear. Under Image Size, you can toggle between pixels, percent, inches, millimeters, points, picas, and more. If you have a specific pixel width or height in mind, change either one (or both) accordingly. GIMP preserves the aspect ratio of your image automatically.

For example, if you change the width, simply click inside the height box and the calculation for the height will immediately appear. You also have the option to change the X and Y resolution.

As for quality, unless you have a particular requirement, leave the Quality set to default: Sinc (Lanczos 3).

In this example, I am reducing the image by one half of its original size. So I select percent in the dropdown box. I change the width to 50 and then let GIMP automatically fill in the height of 50 for me. Do what you want, then click Scale. This opens the Scale Image dialog.

Now you need to save your image. To permanently resize the image, select File >> Save. If you want to keep the original as it is and have the resized image, too, click File >> Save as.

Give your image a meaningful name, select a location and click Save.

Here, GIMP will prompt you to set the quality of your image. The higher the quality, the larger the file. I find 85 to be a decent compromise. When you’re done with your entry, click Save.

That's all there is to it. Quit GIMP by selecting File >> Quit.

Confirm that you indeed have the image and that it looks the way you expected. In this example, I saved the image in a folder I created called GIMP Pictures. I have both the original and the resized image.

Based in Southern California, Buzz Garwood is a senior contributor at BYTE. Follow him @buzzgarwood, or email him at

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
How Enterprises Are Attacking the IT Security Enterprise
How Enterprises Are Attacking the IT Security Enterprise
To learn more about what organizations are doing to tackle attacks and threats we surveyed a group of 300 IT and infosec professionals to find out what their biggest IT security challenges are and what they're doing to defend against today's threats. Download the report to see what they're saying.
Register for InformationWeek Newsletters
White Papers
Current Issue
2017 State of IT Report
In today's technology-driven world, "innovation" has become a basic expectation. IT leaders are tasked with making technical magic, improving customer experience, and boosting the bottom line -- yet often without any increase to the IT budget. How are organizations striking the balance between new initiatives and cost control? Download our report to learn about the biggest challenges and how savvy IT executives are overcoming them.
Twitter Feed
Sponsored Live Streaming Video
Everything You've Been Told About Mobility Is Wrong
Attend this video symposium with Sean Wisdom, Global Director of Mobility Solutions, and learn about how you can harness powerful new products to mobilize your business potential.
Flash Poll