Demystifying HEIC and HEIF files
If you’re the proud owner of a state-of-the-art camera from Canon or Sony, you may have stumbled across a curious new file type. The old standards are still there, including RAW and JPEG, but you may have also noticed a file option called HEIC or HEIF. Both are acronyms for the same file type. HEIF stands for (High Efficiency Image File Format) and HEIC stands for (High Efficiency Image Codec). Regardless of which acronym you come across, they both refer to the same thing. It is a high compression image format based on MPEG compression technology. MPEG is a compression algorithm created to reduce the size of video files while maintaining high quality. In 2015, MPEG technology was used to create HEIF files. It was meant to be a replacement for the aging standard JPEG, which was created in 1992; so now he is 30 years old.
So is HEIF better than JPEG? The short answer is “yes”. HEIF beats JPEG in almost every way. The most important aspect of which is color. In the world of imaging, we equate this with bit depth. JPEG is limited to 8-bit color (256 colors per channel). 256 shades of red, blue and green resulting in 16.7 million colors in total. HEIF features 16-bit color, which is not just double 8-bit, but more than 16 million times. 16-bit color has 65,536 colors per channel, resulting in more than 281 trillion possible colors. And before you ask the question, “Are 281 trillion colors more than you will ever need?” Yes Yes it is. After all, high-end video shows little to no artifacts when using only 10-bit color, and certainly when you go up to 12-bit. The truth is, most modern cameras only capture 12- to 14-bit colors; which simply means that HEIF is already somewhat future-proof. HEIF also boasts more accurate color as it is capable of being recorded in more accurate chroma subsampling.
I’ll leave the details on chroma subsampling for another time, as it could easily be worth a whole blog. For now, know that if you’re given a choice between 4:2:0 and 4:2:2, as you do with the Sony A7IV; the latter is the option with the greatest potential for color accuracy. This also applies when faced with this same choice in video settings.
So when is 8 bits not enough? You may be saying at this point that you’ve used JPEG files for years without exposing its limitations; So why change? An example of when 8-bit tends to fall apart is when you’re shooting a sky that goes from a very light blue to a very dark blue. Below is a sample showing what you might find when editing an image with that sky. The image above represents the “banda” or visible separations that can occur when limited to 8-bit color.
The amazing thing about HEIF is that the compression is so efficient that you get all those extra colors at no cost to the file size. In fact, HEIF files tend to be about half the size of or from JPEG files of similar resolution. Smaller but with much more information!
So, since HEIF files feature more colors in a smaller file size, why hasn’t it completely replaced JPEG? My best answer is that the world is very slow to change. In fact, the vast majority of programs still don’t support or recognize HEIF files.
If you’re still wondering if you should switch to HEIF, then I would answer that question this way. Give HEIF a try, and if it fits your workflow, make the switch. As of now, many of the programs I like to use in my normal workflow don’t support HEIF yet, so I’m sticking with RAW, JPEG, and DNG. I would love to start using HEIF as soon as possible, so I really hope the world of imaging catches up.
PS For Canon shooters who want to try HEIF, it’s a bit hidden. Take a look at the image below; set the HDR PQ setting to “on” to shoot in HEIF instead of JPEG.