How to Resize an Image

Resizing images is a fundamental task in digital photography. It involves adjusting the dimensions of an image to meet specific requirements, including web, social media, and printing. Skill at resizing ensures that images display properly across various platforms and load quickly, or maintain high quality for printing.

Numerous programs are available that can resize images. These photo editing applications range from basic to advanced. The choice of software often depends on the user’s skill level, operating system, and budget.

This article outlines step-by-step instructions for resizing images on various platforms, including the built-in programs of popular computer operating systems and professional editing programs. In addition, we explain the different requirements to resize images for web use and printing applications.

Let’s Define Some Terms:

Image resizing involves several key terms that are essential to understand.

• Image size: the dimensions of the image. Width and height are measured in pixels, inches, or centimeters.
• File size: the amount of digital storage space that an image file occupies. We measure it in kilobytes (KB) and megabytes (MB).
• Resolution: the sharpness or clarity of an image, measured in pixels per inch (PPI).

Resizing Images on Windows, MacOS, and ChromeOS with Built-in Software

Most computer operating systems offer basic image editing programs that can accomplish resizing. And these user-friendly programs resize images quickly and efficiently, without investing in costly software.

Windows

Dozens of image editing programs are compatible with Windows. However, MS Paint comes pre-installed with Windows. Paint is a free graphics program that edits the most common file formats, including JPEG or JPG, PNG, TIFF, and BMP or Bitmap.

Here are the simple steps to resize images with MS Paint:

1. The quickest method to access MS Paint is simply to right-click on the image and select Open with Paint. Or, to launch Paint, go to Windows Start, then All Programs, and under Accessories click on Paint. From there, you can drag and drop the image into Paint; or select Menu, then Open and select the image to be edited.
2. Click the Resize and Skew icon above “Image.”
3. You have the option to change image size by Percentage or Pixels. To avoid a distorted or stretched image, enter 0 in the Horizontal and Vertical boxes under Skew.
4. Click OK. Then to save the image, click the disc icon at the top or select Save as under File.

MacOS

Preview, an image application built into Apple-branded computers, can resize images. This program is compatible with a number of image formats, including JPEG, JPEG 2000, PDF, PNG, PSD, and TIFF.

Follow these steps to resize images on a Mac. 

1. If Preview opens images by default, simply click the image. If not, right-click on the image and select Open with Preview. 
2. Select Tools from the Menu bar, then select Adjust Size from the drop-down menu.
3. In the Image Dimensions window, you may select a preset size in the Fit into window. If you choose Custom, enter the width and height information. If the lock symbol is displayed, changing width or height maintains the aspect ratio of the original image.
4. Click the OK button to resize the image.
5. Then save the resized image: select File on the menu bar and click Save from the drop-down menu.

ChromeOS

Chrome operating systems include Gallery, an image app with basic editing capability that accepts JPEG, PNG, GIF, BMP, and WEBP.

Resizing images on Gallery is similar to other photo apps.

1. To select the image, right-click it, and choose Open with Gallery from the menu. 
2. At the top, click the Rescale icon. Enter width and height in the appropriate boxes. Select the Lock icon to lock or unlock the aspect ratio.
3. Then, to save the resized image, click Save. If you want to preserve the original image, select File and choose Save as.

Using Premium Software to Resize Images

Image editing programs such as Photoshop, Lightroom, and Luminar provide advanced functions that allow for precise control over image dimensions and resolution. These programs offer the capability to alter image size without losing quality to achieve professional-grade results.

Adobe Photoshop

Photoshop offers a robust image resizer function that includes resampling options.

1. After opening the image in Photoshop, choose Image from the top tool bar, then select Image Size from the drop-down menu.
2. The Image Size dialog box can be resized by dragging a corner of the box. In addition, you can drag the hand icon within the preview window to view a different area of the image. Also, to change preview magnification, click the + or – circles at the bottom of the preview window.
3. Adjust the image resizing parameters by setting Width, Height, and Resolution. I recommend leaving Resample in Automatic.
4. If the image includes layers, select Scale Styles from the gear icon. This will scale all the layers to fit the resized image. Do this only if you choose the Constrain Proportions option.
5. Click OK when you finish setting the parameters. Then, Save the image or continue to edit other post-processing functions.

Adobe Lightroom

You’ll find minor differences in image resizing between Lightroom CC and Lightroom Classic. However, Lightroom simplified resizing functions in the newer versions. In both, the resize operation is incorporated into the Export. Here are the steps: 

1. Make basic adjustments to the original image. Then under File, select Export. A dialog box appears with options for Export Location, File Naming, File Settings, and Image Sizing. 
2. Under Export Location, select the destination in the Export To window. You may opt to rename the image in the Existing Files drop-down.
3. In the File Naming box, retain the original image name or enter a new name.
4. The File Settings options include selections for Image Format. Adjust the Quality slider or select the Limit File Size To box and enter the file size.
5. Image Sizing offers a number of selections in Resize to Fit. Set the image size by Width & Height, Dimensions, Long Edge, Short Edge, Megapixels, or Percentage. Also, set Resolution to the desired image quality for web or print.
6. When you’ve made the desired changes, click Export.

In addition, Lightroom’s export process includes options for Output Sharpening, Metadata, Watermarking, and Post-Processing. Lightroom is powerful and somewhat complicated; however, it’s worth learning.

Luminar

A popular image editing program, Luminar offers a resizing feature similar to Lightroom. Follow these steps:

1. Under File, select Export. A dialog box opens.
2. Select a Location for the file and a File Name.
3. Then, choose the file’s Format and a Sharpen option.
4. You have a variety of selections in the Resize drop-down. Then, enter the desired dimensions in the Size blocks.
5. Also, select Color Space, Resolution, and Quality.
6. Finally, click Export.

GIMP

An open-source image editing program, GIMP is a free alternative to expensive programs. It comes with an impressive range of tools. But it has a steep learning curve.

1. To resize an image, select Image from the top menu bar and click Scale Image.
2. Set the Width and Height to the desired size. In addition, you may set the image Resolution. Then, click Scale.
3. To save the image, go to File and choose Export As. In the dialog box, enter the File Name and the file’s destination. In addition, choose the file format by clicking Select File Type. Another dialog box appears where you adjust image quality and metadata.
4. Then, click Export.

How to Adjust Image Size on a Smartphone Device

Let’s take a quick look at how the size of an image can be adjusted using a smartphone.

iOS

iPhones come with a Photos app, allowing for minor edits such as cropping and adding filters. However, for custom resizing, you’ll need to download an app from the App Store. Most of these apps allow you to change width and height, along with image resolution.

Android

Some Android smartphones offer an image resize function. After selecting an image, tap the edit icon and the three-dot menu. Select Resize and choose a Percentage or Resolution. Then, tap Done and Save.

Sizing Images for Web and Print

Pay careful attention to image size and file size in preparing photos for web or print applications. Each requires specific considerations to ensure optimal quality, appropriate size, and performance.

Optimum image size for web use ranges from 1000 to 2500 pixels, on the longest edge. File size should be less than 500 KB. Resolution is generally 72 PPI. Social media platforms such as Facebook, LinkedIn, and Instagram have specific guidelines for cover photo, profile photo, and post. Take the time to research the recommended image and file sizes for the social media platform you use.

In contrast, print media demands higher resolution images to achieve the necessary detail and quality. Therefore, images are resized to fit specific print dimensions while maintaining a minimum resolution of 240 PPI. This method results in large file sizes, much larger in some cases. But it ensures high quality file for printing.

Conclusion

Understanding how to resize images is essential for optimizing the files for various applications, whether it’s for printing, a web post, or sharing on social media.

I hope this article enhances your understanding of how proper size and resolution are crucial to ensuring the final image exceeds the minimum standards.

Finally, If you have any questions or comments, please submit them in the space below.

Take Away

Properly resized images are essential for web use, social media, and printing. Image files that are optimized for posting on web sites or social media contribute to the overall efficiency and appeal of digital content. Images for printing are resized to specified dimensions that meet the requirements of the printing process.