Well, turns out a lot of people do! 1,647,831 images (38.9%) of the images we analysed stored some sort of metadata. ICC (colour profiles embedded in a pic - more on this later)ĭo people really store such stuff in images?.XMP (XML stuff Adobe inserts into pics).EXIF (information added by camera manufacturers containing settings used when taking the photo, etc.).There are different formats which can be used to store metadata in JPEG images. Let that sink in - if each of these top sites were just visited once, nearly 13 GB of data could have been saved on the internet if these websites were handling the metadata properly! Formats to store metadataīefore we look at why so much metadata is stored in images, let us take a peek on how this is usually stored in images. In these images, metadata occupies 15.8% of the total image size on an average. We found that 38.9% of those images had some sort of metadata in them. We then downloaded and analysed the metadata from this dataset. We used the HTTP Archive crawl from 1st August,2016 which contained 4.3 million JPEG images from the top 500,000 websites, totalling up to 195GB.

We used the data from the HTTP Archive and some BigQuery magic to generate a list of URLs of valid JPEG images. In this post, we will specifically focus on the different kinds of metadata stored in JPEG images and the impact this has on performance of a webpage. On an average, this kind of metadata occupies 16% of size of the JPEG file. A JPEG file also has a lot of metadata in each file containing auxiliary information about the image. A typical JPEG file contains a lot more information than just the bytes required to store image data.

Image metadata viewer