High Efficiency Image File Format

"HEIF" redirects here. For the Higher Education Innovation Fund, see Research England.

"heic" redirects here. For other uses, see HEIC.

High Efficiency Image File Format (HEIF) is an international standard defined by MPEG-H Part 12 (ISO/IEC 3008-12), first published by ISO in 2017. It is designed as a container for photographic images in any image encoding. HEIF is a special case of the general ISO BMFF format, in which all data is encapsulated in typed boxes, with a mandatory ftyp box that is used to indicate particular file types. The initial specification for HEIF provided usage details for three compression schemes, the widely supported JPEG encoding for still raster images and two video encodings that are also applicable to still image items, namely Advanced Video Coding (AVC, aka MPEG-4, Part 10 and H.264) and High Efficiency Video Coding (HEVC aka PEG-H Part 2 and H.265).

High Efficiency Image File Format (HEIF)

Comparison of JPEG, JPEG 2000, JPEG XR and HEIF files at similar file sizes
Filename extension	.heif, .heifs; .heic, .heics; .avci, .avcs; .HIF
Internet media type	image/heif, image/heif-sequence; image/heic, image/heic-sequence; image/avif
Uniform Type Identifier (UTI)	public.heif, public.heic
Developed by	Moving Picture Experts Group (MPEG)
Type of format	Image container
Extended from	ISOBMFF
Standard	ISO/IEC 23008-12 (MPEG-H Part 12)
Open format?	Depends on contained format (e.g. HEIC vs. free AV1 Image File Format)
Website	www.iso.org/standard/83650.html

ISO Base Media File Format official specification (of which HEIF is a special case) defines multiple subtypes in relations to possible encodings:

• MJP2_FF, Motion JPEG 2000 File Format
• MP4_FF_2, MPEG-4 File Format, version 2
• MP4_FF_AVCE, MPEG-4 File Format for AVC (Extensions; Part 15)
• JP2_FF, JPEG 2000 Part 1 (Core) jp2 File Format
• JPX_FF, JPEG 2000 Part 2 (Extensions) jpf File Format
• JPM_FF, JPEG 2000 Part 1 (Compound) jpm File Format
• JPEG_XL, JPEG XL Image Encoding
• JXL, JPEG XL File Format
• HEIF, High Efficiency Image File Format. Some internal structures required for HEIF were added into the ISO_BMFF specification in a 2018 amendment. (ISO/IEC 14496-12:2015/Amd 2:2018)

BMFF HEIC/HEIX Registered Brands

Specific implementations of HEIF encoding are registered by MP4RA and are officially called "brands".

According to official specifications Apple HEIC registered brand is using Main or Main Still Picture profile of HEVC with an 8-bit per channel color depth and chroma subsampling of 4:2:0, while Sony and Canon HIEX registered brand may additionally increase the bit-depth to 10 bits per channel and chroma subsampling to 4:2:2 or 4:4:4.

Licensing and Patents

If BMFF HEIF is used with HEVC encoding is woth noting that HEV is heavily encumbered with patents and Library of Congress does not recommend of using such heavily patent troublesome formats. The parties holding patents on HEVC include but are not limited to:

• Apple
• Matsushita Electric Industrial Co
• Toshiba Corp.
• Lenovo

The uncertainty of patent encumbering is farther strengthened by unclear patents holders wordings. Holders of relevant patents, stated to the ISO that "the holders of these patent rights have assured the ISO and IEC that they are willing to negotiate licenses under reasonable and non-discriminatory terms." The specification also cautions that "some of the elements . . . may be the subject of patent rights other than those identified."

History

The requirements and main use cases of HEIF were defined in 2013. The technical development of the specification took about one and a half years and was finalized in the middle of 2015.

Apple was the first major adopter of the format in 2017 with the introduction of iOS 11 using HEIC variant. While HEIC became the default for iPhones, it remains possible to revert the settings to allow photos to be recorded in the more recognizable JPEG format.

Android devices containing the appropriate hardware encoders received support for HEIC files with the release of Android 10 (2019).

On some systems, pictures stored in the HEIC format are converted automatically to the older JPEG format when they are sent outside of the system, although incompatibility has led to problems such as US Advanced Placement test takers failing due to their phones uploading unsupported HEIC images by default, leading the College Board to request students change the settings to send only JPEG files.

Although HEIC is gaining in popularity there are issues with compatibility, Adobe Photoshop is an example of a popular image editing software that only supports 8-bit HEIC and not 10-bit or 12-bit HEIC yet.

Camera hardware (including mobile devices) are increasingly supporting outputting HEIC files and with color depth often higher than 8-bit color.

Specifications

HEIF files can store the following types of data:

Image items

Storage of individual images, image properties and thumbnails.

Image derivations

Derived images enable non-destructive image editing, and are created on the fly by the rendering software using editing instructions stored separately in the HEIF file. These instructions (rectangular cropping, rotation by one, two or three quarter-turns, timed graphic overlays, etc.) and images are stored separately in the HEIF file, and describe specific transformations to be applied to the input images. The storage overhead of derived images is small.

Image sequences

Storage of multiple time-related and/or temporally predicted images (like a burst-photo shot or cinemagraph animation), their properties and thumbnails. Different prediction options can be used in order to exploit the temporal and spatial similarities between the images. Hence, file sizes can be drastically reduced when many images are stored in the same HEIF file.

Auxiliary image items

Storage of image data, such as an alpha plane or a depth map, which complements another image item. These data are not displayed as such, but used in various forms to complement another image item.

Image metadata

Storage of EXIF, XMP and similar metadata which accompany the images stored in the HEIF file.

Encodings inside the container

HEIF container specification describes various encodings that can be stored inside:

• JFIF (JPEG)
• AV1
• HEVC

These leads to confusion, as users cannot tell what kind of encoding has been used. Simply saying that “HEIF is better than JPEG” as promotional material doesn't mean anything to the user.

Inside the HEIF container, JFIF (JPEG) can be stored. It can also contain AV1 encoding. The user would also need to know the encoding parameters in which the encoding happened (e.g., color quality "q", if delta in chroma planes were used, if some advanced tuning for ssim/psnr was used, or what quantization mode was applied).

If a user creates a ".HEIF" photo with their phone, the user or the receiver of the photo cannot determine which image format inside the file was used. It could be:

• a JFIF (JPEG);
• a poor quality (default settings) AV1; or
• a very high quality AV1 encoding (which takes a lot of processing power and takes a few minutes to encode); or
• an HEVC with poor quality parameters; or
• an HEVC with high quality parameters.

Hence, simply stating in promotional materials that “HEIF is better” doesn't mean anything at all, as HEIF is just a container specification. What is contained inside the container must be described.

It's impossible to easily determine exactly what you receive in HEIF container. At best, users can use graphics magic to determine if it's impossible by visual inspection (gradients transitions are broken in 8-bit photos) to tell if the photo is 12-bit or 10-bit per channel, or 8-bit.

MIAF

The Multi-Image Application Format (MIAF) is a restricted subset of HEIF specified as part of MPEG-A. It defines a set of additional constraints to simplify format options, specific alpha plane formats, profiles and levels as well as metadata formats and brands, and rules for how to extend the format.

AVCI: AVC in HEIF

Advanced Video Coding (AVC, ITU-T H.264) is an older encoding format for video and images, first standardized in 2003. It is also specified as a codec to be supported in HEIF in normative Annex 5 to ISO/IEC 23008-12. The registered MIME types are image/avci for still images and image/avcs for sequences. The format is simply known as AVCI.

Apple products support playback of AVC-encoded .avci still image files and .avcs image sequence files but will only generate .heic files.

AVIF: AV1 in HEIF

This section is about AV1 and AVIF. For AVI, see Audio Video Interleave.

Main article: AVIF

AV1 is a video encoding format that is intended to be royalty-free, developed by the Alliance for Open Media (AOMedia). AV1 Image File Format (AVIF) is an image format based on this codec.

The registered MIME type is image/avif for both still images and image sequences, and .avif is the file name extension.

JPEG compression formats in HEIF files

The original JPEG standard is the most commonly used and widely supported lossy image coding format. It was first released in 1992 by ITU-T and ISO/IEC. Although Annex H to ISO/IEC 23008-12 specifies JPEG (and indirectly Motion JPEG) as a possible format for HEIF coded image data, it is used in HEIF only for thumbnails and other secondary images. Therefore, neither a dedicated MIME subtype nor a special file extension is available for storage of JPEG files in HEIF container files.

Several other compression formats defined by the JPEG group can be stored in HEIF files:

• Part 16 of the JPEG 2000 standard suite (ISO/IEC 15444-16 and ITU-T Rec. T.815) defines how to store JPEG 2000 images in HEIF container files. Part 2 of the JPEG 2000 suite (ISO/IEC 15444-2 and ITU-T Rec. T.801) also defines a different format for storing JPEG 2000 images in files that is also based on ISOBMFF.
• Annex F of the JPEG XR image coding standard (ISO/IEC 29199-2 and ITU-T Rec. T.832) defines how to store JPEG XR images in HEIF container files. Annex A of JPEG XR also defines a different file format for storing JPEG XR images in files that is TIFF-based, and Part 2 of the JPEG 2000 suite (ISO/IEC 15444-2 and ITU-T Rec. T.801) also supports a third file format for storing JPEG XR images in files that is based on ISOBMFF.
• JPEG XS has its HEIF container support defined in ISO/IEC 21122-3.

In 2017, Apple announced that it would adopt HEIC as the default image format in its new operating systems, gradually replacing JPEG.

WXAM, SharpP

The proprietary image format WXAM (or wxHEPC) developed by Tencent (used within, e.g., WeChat) is apparently based upon HEVC, as is SharpP, which was developed by their SNG (Social Network Group) division. However, their container format may not be HEIF-compatible. In March 2017, SharpP switched to AVS2 and was renamed TPG (Tiny Portable Graphics).

Support

See also: AVIF § Support

• Nokia provides an open source Java HEIF decoder.
• The open source library "libheif" supports reading and writing HEIF files. From version 1.8.0, both reading and writing HEIC and AVIF are supported.
• An image codec called CopyTrans HEIC, which is free for personal use and available for Windows versions 7 through 10, supports opening HEIF files in Windows Photo Viewer without the Microsoft codec installed. (The Microsoft HEIC codec is only available for Windows 10, version 1803 and up in the Photos UWP app.)

Operating systems

• Windows 10 version 1803 and later (HEIC), version 1903 and later (AVIF): HEIF Image Extension is needed to read and write files that use the HEIF format. HEVC Video Extensions is needed to play and produce HEVC-encoded video content. A small amount of money is charged for the use of the HEVC codec, whereas support for the generic HEIF format and the AVC and AV1 extensions are free.
• Windows 11: since 22H2, Windows 11 has HEIF Image Extension built-in by default.
• macOS High Sierra and later (HEIC only) Since macOS Mojave, Apple uses HEIF in creating the Dynamic Desktop feature.
• iOS 11 and later (HEIC only) iOS 16 and later AVIF
• Apple supports playback of .heif for still image files and .heifs for image sequence files created on other devices that are encoded using any codec, provided that codec is supported by the operating system.
• Android 8 (Oreo) and later (HEIF), Android 10 and later (HEIC), Android 12 and later (AVIF). Android 13 and higher support 10-bit camera output.
• Ubuntu 20.04 and later (HEIC)
• Debian 10.13 ("buster") or later

Web browsers

As of August 2024, only Safari supports HEIC format natively.

For AVIF, Chrome, Firefox and Opera for desktop and Android support it. Safari on iOS 16 and iPadOS 16 supports AVIF format.

Image editing software

• Adobe Lightroom (macOS 10.13+, iOS 11+, Windows 10+, and Android 9+)
• Adobe Photoshop
  • (Note that Photoshop for Windows requires the installation of both the HEIF and HEVC CODECs available from Microsoft.)
  • Photoshop reads HEIC files, but as of 2022 does not allow saving to that format.
• Affinity Photo
• GIMP supports reading and exporting to HEIF since version 2.10.2, released in May 2018.
• Darktable
• Digikam (supports 10-bit HEIC)
• GraphicConverter
• ImageMagick
• Krita
• Paint.net
• PaintShop Pro
• Pixelmator
• Zoner Photo Studio X
• ACDSee (read-only)
• XnView

Hardware

• The Canon EOS-1D X Mark III, Canon EOS R5, Canon EOS R6 and Canon EOS R8 cameras use the HEIF format to capture images in an HDR display format that use the PQ tone curve, BT.2100 color primaries and 10-bit. "We've moved on to HEIF files," Canon said in 2019.
• The Sony α1 and Sony α7 IV offer capturing images in 10-bit HEIF format with an HDR format that uses HLG.
• The Fujifilm X-H2S, Fujifilm X-H2, Fujifilm X-T5, and Fujifilm X100VI offers a choice of JPEG or 10-bit HEIF file formats.
• The Nikon Z9 and Nikon Z8 offer 10-bit HEIF file formats.
• Multiple Qualcomm Snapdragon SoCs support capturing images in HEIC format (e.g. Snapdragon 888, Snapdragon 662). Some of their latest SoCs also support capturing in HEIC with HDR (e.g. Snapdragon 8 Gen 1, Snapdragon 780).
• The iPhone 7 and later devices from Apple can capture media in HEIF or HEVC format.
• Android smartphones like Xiaomi 12, OPPO Reno 7 5G, Samsung Galaxy S21 5G can capture images in HEIF format. Android 13 and higher support 10-bit camera output.
• The Hasselblad X2D camera following updates had been updated to support 10-bit HEIF output. The CFV 100C digital back was released also supporting the HEIF format.

Websites

• During May 2020, online Advanced Placement exams allowed students to submit photos of handwritten responses. Because the website was unable to process HEIF images, students whose phones defaulted to this image format were considered to have not submitted any response and often failed to complete the exam. College Board, which administers the exams, later provided a system for users to submit photos of answers via email. Because the iOS Mail app automatically converts HEIF images to JPEG, this mitigated the problem.
• Facebook supports the upload of HEIC but converts to JPEG or WEBP on display.
• Discord does not support HEIC at all.

Patent licensing

Further information: High Efficiency Video Coding § Patent holders

HEIF itself is a container that may not be subject to additional royalty fees for commercial ISOBMFF licensees. Note however that Nokia also grants its patents on a royalty-free basis for non-commercial purposes. When containing images and image sequences encoded in a particular format (e.g. HEVC or AVC) its use becomes subject to the licensing of patents on the coding format.

See also

• Better Portable Graphics (BPG) – another image file format using HEVC encoding, published by Fabrice Bellard in 2014
• JPEG XL – an image file format developed since 2019 (standardization completed since 2022) and based on Google PIK and Cloudinary FLIF (itself based upon FUIF) claiming to outperform PNG, WebP, BPG and JPEG 2000 for lossless encoding at least
• WebP – an image file format based on the VP8 and VP9 video formats

External links

• Official website
• HEIF – MPEG Image File Format standard site
• HEIF – format site at Nokia with source code at GitHub
• libheif – source code at GitHub
• Sample HEIC files - image gallery at HEIC Digital