Interlaced Images and Progressive Images

When it comes to image optimization, it is essential to recognize different encoding methods which affect the way the image loads and how the viewers think about the image. This is useful for displaying and rendering large images, the combination of interlaced encoding and progressive encoding can be beneficial for use of images in media.

What are Interlaced Images?

Interlaced image loads and displays the image "line by line". At first, the image will display as a whole but highly blurry image, this will give viewers a more meaningful content of the image. The more the data is loaded, the more precise the image appears. Until all of the data is fully loaded, the full version of the image will be displayed.

This way, viewers will grasp a general idea of the image and then see a whole clear image later.

What are Progressive Images?

Progressive Image loads and displays the image "broadly", it is a bit more complex. Image-viewing software loads a portion of an image quickly, then display a rather pixelated image, and then continues loading the image until all of the data is loaded and displays a full version of the image.

With this approach, loading and displaying, viewers will also get some information about the image quickly and then see a full version later.

Difference between Interlaced Images and Progressive Images

Both interlaced images and progressive images load a portion of the image each time, starting from a blurry and pixelated image to a clearer, full-solution version of images.

The difference between interlaced images and progressive images is not in the storage size or image quality but in the way they are encoded and displayed. The interlaced image loads data "line by line", each time it loads a portion of the data, the image gets clearer and more precise until all of the data is loaded and the image is now fully loaded. The progressive image loads "layer by layer", the image will be blurry at first, and then, bit by bit, the image will be fully rendered.

With two different approaches, both interlaced images and progressive are suitable to be used on the internet. In this way, viewers will experience less waiting time and faster rendering speed.