Image File Formats

Whether print or digital, images are a major part of our lives. They fill our inboxes, help us quickly gather information, capture our memories, and the list goes on and on. But there is more than meets the eye. Image files come in a variety of formats (.jpeg, .pdf, .png, etc.) that should be used for specific projects or instances. Using the correct file formats at the right time will help guarantee that your product image, logo, or selfie is well received by the intended audience. If you’d like to master image file types or have a case of the Monday’s (regardless of the day) this article is for you! Let’s get started with part one of this three series lesson.

To fully understand image file formats and when best to use them, you have to know the difference between two image groups – vector and raster. The majority of image files fit into one (or sometimes both) of these groups and each group has specific uses, advantages, and disadvantages. Being able to distinguish between vector and raster if the first step of selecting an image file format for your project.

Vector Images

They say a picture is worth a thousand words but in the case of vector images, it can also be said a picture is made of a thousand shapes. Vector graphics are geometric equations that are displayed as shapes e.g. lines, curves, dots, rectangles, etc. Due to the mathematical makeup of vector images, they are rendered exactly the same regardless of the size. This means that you’ll never have to worry about a loss of image quality when resizing.

Vector graphics are the preferred image file type when working with logos, icons, fonts, illustrations or other line art graphics. Common vector software includes:

  • AI
  • CorelDraw
  • Inkscape

Raster Images

Raster images are comprised of tiny squares known as pixels and range from complex photographs to simple illustrations. They are the most common image file format (e.g. JPG, PNG, and GIF) and are typically used on the web. Resizing raster graphics can be difficult because they have a fixed number of pixels (e.g. 72ppi has 72 pixels, 150ppi has 150 pixels, etc.). If you added pixels to a raster image without changing the image size, pixels would be added at random causing the image to look blurry. Expanding the image without changing the number of pixels will also yield a blurry image. This is because the software is unable to determine missing image data. To avoid this problem it is best to work at the desired scale.

Common raster software includes:

  • Photoshop
  • Gimp
  • PaintShop

Bonus Round: Image Color Formats

CYMK

  • Subtractive color mode: cyan, magenta, yellow, and key (aka black)
  • Use when designing printed materials
  • Used by professional and home printers

RGB

  • Additive color mode: red, green, blue
  • Offers the widest selection of colors
  • Use when designing web materials
  • Associated with monitors e.g. televisions, cell phones, tablets, etc.

 

This concludes the first image file format lesson. The next article in the series will address the three major vector image formats; EPS, PDF, and AI. Check back next week for Image File Formats: Part 2.

Rely on an Expert

Don’t feel confident in your abilities to tackle image file formats? Our designers are second to none at creating and optimizing vector and raster graphics. Contact us today; we are always here to help!