Image File Formats, Editing Tools and the Ethics of Image Editing

Digital Image File Formats

Digital images are encoded data files and there are a variety of formats each suited to different uses. Images for screen-based use will have different requirements than those prepared for printing. Below are resources that provide information on best practices for common digital image use.

  • Image file formats: everything you’ve ever wanted to know from 99designs walks you through image file types and terminology, explains the difference between raster (e.g. JPEG, GIF, PNG, TIFF, RAW, and PSD) and vector (e.g. EPS, SVG, and AI) images, lossy and lossless formats, colour codes, and gives examples of the most suitable uses for each.
  • Image File Types: Top 5 Types of Picture Formats by 1rstWebDesigner explains the pros and cons of GIF, JPEG, BMP, TIFF, and PNG formats and suggest which types are most appropriate for a variety of uses.
  • A few scanning tips created and maintained by Wayne Fulton takes an in-depth look at image file formats, image resolution, and provides a simple table that lays out the best formats for general uses.

Editing Images

Including visual content in your work often requires adapting and editing images in order to optimize visual quality. A good place to start is to familiarizing yourself with digital image terminology.

Basic Image Editing Tips:

  1. Begin with the highest quality image file possible. Images can be reduced in size quite successfully, but making them bigger ("ressing up") does not usually work very well. 
  2. When editing an image file always sharpen (i.e. use the "sharpen" filter) last (and at 100% zoom) to ensure that your image is in focus.
  3. Always save an unedited master copy of your image in case your editing goes wrong and you need to start again.
  4. If appropriate, crop rather than resize - it maintains the  aspect ratio.

For more tips see:

12 Common Image Formatting Mistakes To Avoid On Your Website from Canva's Design School offers advice on how to ensure that images display properly on the websites.

Digital Photo Editing Workflow – Better Images From Capture to Output from the Digital Photography School provides a comprehensive look at the essential steps and principles in an effective photo editing workflow with highlights of key tools.

The Ethics of Image Editiing

While editing an image to suit your project can increase its visual appeal and the effectiveness of your project, it is important to recognize that reworking an image can have unintended consequences.

Not only can you change the meaning of the image through alteration, you can also be in violation of an image creator’s copyright. Be mindful of how editing or re-contextualizing an image can drastically alter its meaning and always check an image’s copyright status or licensing terms to ensure that you are using an image ethically and legally.

If you have made substantial changes to an existing image you found online (for example, edited out a person or object or completely changed colours or compositional elements) be sure you are able to make this changes (check licensing terms and copyright status) and always state that the image has been altered by you when citing the original.

Free Image Editing Tools

Compressor.io is an online tool for drastically reducing the size of your images and photos whiles maintaining a high quality with almost no difference before and after compression. The tool supports the following file formats: JPEG, PNG, GIV, and SVG.

GIMP (GNU Image Manipulation Program) is a free open source software alternative to Adobe Photoshop and is available for Mac and Windows. It provides a collection of professional-quality functions for fine-tuning images and photos and allows you to create your own artwork from scratch.

The Nik Collection is a free full image-editing suite offered by Google. The Collection includes seven plugins and you can download tools as you need them, or download them all and use them interchangeably.

Pixlr offers a variety of online image editing solutions that can be used from a variety of devices, including Android, Windows and Mac.

Sumo Paint is an online image editor that doesn't require you to install anything on your computer. It's a versatile photo editor and paint application that works in your web browser. You can open and save images from your hard drive or save it to the cloud.

Content last updated: February 6, 2019