What is an HEIC File? Everything You Need to Know

A HEIC is an image file type that contains compressed data, along with metadata such as where a photo was taken, when it was created, etc. Although it reduces image information, it generally results in a better representation of the original source than an image saved in JPEG format.

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What does HEIC mean?

HEIC stands for High-Efficiency Image Coding and contains images stored using a variation of HEIF, High-Efficiency Image Format. The efficiency of an image format refers to the space required to store a file with high quality and visual accuracy. Every HEIC file is a HEIF image, however, not all HEIFs are HEICs. Both offer much greater fidelity at the same file size than image formats, such as the old type of JPEG compression that was essential for the early days of the Internet.

In many cases, HEIF is used as a replacement for JPEG images. Most notably, all new Apple products can open, edit, and save HEIF-compressed images as HEIC files. The iPhone saves photos in HEIC format by default, however, there is an option to use JPEG. Many major digital imaging companies support HEIF and HEIC, including Canon, Sony, Qualcomm, and Samsung.

How does HEIC compress a photo?

HEIC uses an image compression codec that was first developed for video. High Efficiency Video Coding (HEVC) compresses each frame of a video with discrete cosine and sine transforms (DCT and DST) with block sizes ranging from 4×4 pixels to 32×32 pixels. This greater range of compression techniques has a dramatic effect on the visual fidelity of the image, providing more detail where it’s needed most.

HEVC uses variable pixel block sizes for efficiency.

When used to compress video, HEVC also uses inter-frame compression because the scene often has very little change in the split second between frames. This allows video to be compressed more than a photograph. Even so, HEVC is very good at compressing images and is more efficient than most image formats.

How much space does HEIC save?

HEIC is twice as efficient as JPEG. This means it maintains similar visual fidelity at different quality levels as JPEG while requiring half the storage space. An image saved as a 4 megabyte HEIC file will need 8 megabytes to look as good when using JPEG compression.

A comparison of the quality of JPEG and HEIF photos at similar file sizes. Photo by John and comparison by Christoffer and licensed under GNU FDL.

While 4 megabytes is an insignificant amount, on a library of thousands of photos the savings can be measured in gigabytes. File transfers are faster with HEIC and downloads will be faster even when using a cellular network.

Are there any downsides to using HEIC?

In most cases, using HEIC is a good way to save space and speed up file transfers. It does not degrade an image as much as a file of the same size using the JPEG format. It is also a more versatile format that allows for more varied types of metadata than JPEG.

Sharing and editing a HEIC file can sometimes require an extra conversion step because Windows and Linux do not recognize this format. As the default format for an iPhone, this can be annoying, however, iOS automatically converts a HEIC file to JPEG when sharing an iPhone directly to an incompatible computer. The conflict arises when iPhone photos are transferred to an external drive or uploaded to cloud storage before being transferred to an incompatible system.

Another concern is making HEIC files available online. Few web browsers support HEIC files and even Apple’s Safari browser restricts the use of a HEIC file, allowing this type of file to be chosen as the background image for new tabs, but without it. charge directly. However, social media networks convert HEIC to another format, so it’s only a problem if you’re uploading directly to a private server or network that might not recognize the format.

It’s easy to convert HEIC to JPEG if needed, and many popular photo editing apps can load a HEIC file for editing even if it can’t be previewed in the computer’s file manager. Both Windows and Linux have free extensions that make HEIC and HEIF files as accessible as a JPEG in the operating system.

Alternatives to HEIC: JPEG, WebP, RAW and ProRAW

Most cameras capable of capturing photos in HEIC or HEIF format include the option of saving in the more common JPEG format. As mentioned above, JPEG offers better compatibility but at the cost of larger file sizes.

In most cases, it is also possible to save an image as a RAW photo. The RAW format is generally unprocessed and uncompressed, which offers the best possible quality but much larger file sizes, requiring around five to ten times more space than JPEG or HEIC for storage.

An iPhone can capture a variant of the RAW format called ProRAW. The iPhone’s camera app processes images recorded in ProRAW format with Apple’s DeepFusion, Smart HDR, and Night Mode features, delivering all the benefits of a standard photo while saving an uncompressed image that retains its best publishing quality.

Apple ProRAW processes with AI but saves in RAW format.

When saving a photo for sharing or archiving without the need for uncompressed quality, WebP is even more efficient than HEIC and has a lossless compression option. WebP is recognized by most web browsers, so it’s a good choice for websites and that’s why Google developed this format.

The Many File Extensions of HEIC: It’s Not Just .heic

As with most image formats, there are several file extensions associated with HEIC and HEIF files. Apple only uses .heic, while Canon and Sony prefer .hif. Other file extensions include: .heif, .heifs; .heic, .heics; .avci, .avcs; .vivif, .vivives.

Files with extensions ending in an “s” indicate a sequence of images, somewhat similar to animated GIF files. You can expect to see HEICS files when using AirDrop to send an iPhone Live Photo to a computer, however, Apple’s default setting is to send a HEIC file that only contains a single image, not the full animation.

There is an option to share all photo data resulting in a folder containing a HEIC file for the image and a HEVC file for the video. HEIC and HEIF image sequences are used by applications, but are generally not used for sharing and are rarely seen by the end user.

Who made HEIC and why?

While Apple adopted the HEIC file type in 2017, HEIF and HEIC files already existed before then, with the standard being finalized by the Moving Pictures Expert Group in 2015. This collaborative effort also created the video format of the same name, MPEG.

The Motion Picture Expert Group developed HEIC.

HEVC is a closely related technique which is used to compress video and stands for high efficiency video coding. As important as it is to reduce the file size of a photograph, storing a video is even more demanding since it typically consists of 30-60 frames for every second of video.

MPEG developers and members were highly motivated to find a way to improve the accessibility of digital video and advance the industry by dramatically reducing bandwidth requirements while maintaining quality. In particular, keeping each frame at higher fidelity makes video editing easier. HEVC achieves this with a reduced file size and that is why it was used in the very popular H.265 video codec. HEVC is also a very good image compression technique and is far superior to JPEG.

Why does Apple use HEIC?

HEIC files are one of the most efficient ways to store images while maintaining good quality, but that’s not the only reason why Apple implemented this format. HEIC can also include an alpha channel, allowing it to store images with transparency. A depth map makes it easy to include LiDAR scans and depth estimates with an image. This versatility makes HEIC a much more useful format to use as a standard in Apple’s ecosystem.

The High Efficiency Image Format was adopted by Apple and announced during its keynote in 2017.

Conclusion

HEIC files have been around for many years and exploded in popularity when Apple made HEIC the default format for every iPhone in 2017. When using an Apple device, HEIC files are recognized and can be used with the same easier than the more popular JPEG format.

Although HEIC files can cause some problems on Windows and Linux computers under certain circumstances, there are free image utilities that can convert HEIC to JPEG format. HEIC image converters are available online and as apps for macOS, Windows, and Linux systems.

iCloud, Google Photos, OneDrive, Adobe Creative Cloud, and Amazon Photos all support HEIC and HEIF images, making them a good way to save on subscription fees. It may even be worth converting a JPEG library to HEIC or HEIF before uploading it to the cloud to reduce the amount of storage used.

HEIC does not solve all needs and there is still a lot to do. WebP is usually even more efficient, and RAW files offer the best possible quality. HEIC is however a very versatile and convenient format for Apple devices and is popular enough to be supported for the foreseeable future.

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