HEIC Files

What is a .HEIC file?

.heic file refers to an image in HEIF format that is encoded primarily with an encoding that compresses the main image in a manner based on the compression used by HEVC/H.265. HEIC can also be expanded as High-Efficiency Image Container or High Efficiency Image Coding, although the image itself is contained within the HEIF file which is standardized by MPEG as ISO/IEC 23008-12 and has been developed through cooperation of the committee of MPEG in addition to Nokia and members of MPEG.

The majority of people can usually see a heic file as photographs captured through the iPhone or iPad when high-efficiency photo capture is enabled within its settings. This behavior was first included in iOS 11 by Apple and was first enabled on their devices that have Apple A9 class processors or any higher class processor. A heic file could contain a still image or even a burst-style photo series, a preview, a transparency plane or channel, a depth map, some gain map-related information about an HDR and Exif metadata among others in addition to many other images.

Usually a heic image will appear as a combination of heic image along another movie that appears separately in a sidecar called .mov instead of having a single moving heic image file of such a kind of a movie file. The corresponding file extension here is .HEIF which has no limitation of HEVC codec, and .HEICS which includes multiple sequential images. Moreover, there is no major legacy format related to that file that makes use of .heic extension.

How to open a .HEIC file

Technical details

HEIC file consists of binary ISO Base Media File Format container instead of being a bitmap file format. The organization of this type utilizes MP4/QuickTime-box-based layout, that is atoms with a corresponding size prefix, 4 bytes. In most HEIC files, byte position #4 will contain an ASCII string 'ftyp' with representation of the hexadecimal value 66 74 79 70. These file types have compatible file types or file brand values such as 'heic', 'heix', 'mif1', 'msf1', or 'miaf'.

Metadata that comes with the format might be in form of EXIF, XMP, color ICC Profiles as well as GPS data and orientation. This format can be extended in order to store additional images or auxiliary images like overlay, rotated crop, grid, alpha depth, thumbnail, etc. HEIF also allows metadata containing the data for GPS data or XMP or capture time, camera, as well as Exif and ICC color profiles, GPS data and camera. It is a fully specified and publicly available ISO Standard which currently uses the latest revision of the following standard specification: ISO/IEC 23008-12:2022. The technology used in compression, on the contrary, is patent-licensed HEVC technology which makes the format less popular in open source or across browsers in general.

Most smartphones use HEIC lossy image compression that produces about 30-60 percent smaller picture compared with JPEG pictures of identical quality. The registered image MIME type is image/heic and also a sequential format mime is image/heic-sequence (generic formats use mime-types: image/heif and image/heif-sequence); most typical file sizes: hundreds Kilobytes to megabytes.

How to convert .HEIC files

HEIC should be converted to JPEG format when the destination cannot use an input of image/heic type; the recipient can include a website upload, form, print terminal, and old software product. This solution is used in cases requiring the basic approach to interoperability. Using ImageMagick one needs to use magick input.heic -auto-orient -quality 90 output.jpgCopy while having installed a build which supports the HEIC format through libraries such as libheif. In case of lacking this particular delegate, ImageMagick informs a user about no available HEIC format decoder.

PNG image file format should be used when a picture requires transparency and non-loss editing. Command line should include command such as magick input.heic -auto-orient output.png.Copy User must be ready for large files especially from camera photos. One should realize that some HEIC information is lost during the converting process.

TIFF format may be used during the working with printing, scanning and archiving procedures. Conversion should include command such as "magick input.heic -auto-orient -define tiff:compression=zip output.tif".Copy Although TIFF gives more space in edits than JPEG, its files tend to become significantly bigger.

The last case includes usage of pdf format whenever the images need to be used as documents or joined in one document with other pages. This case is easy for printing and difficult for editing pictures. Commands are similar to the previous one, with output.pdf as the output file.

Common problems and fixes

Windows Photos may show “We can’t open this file” warning and request for the HEIF or HEVC extensions if certain codecs are not available. It is recommended to install Microsoft HEIF Image Extensions via Microsoft Store, then install either Microsoft HEVC Video Extensions or OEM HEVC decoder (depends on OS version), and relaunch program to see this picture anew by restarting of Photos or opening .heic file one more time.

In case some problems with ImageMagick and error like ‘‘no decode delegate for this image format `HEIC’’’ happen - it means that particular installed ImageMagick package doesn’t have the built-in libraries of decoding. Therefore, one should install an ImageMagick library with libheif implementation, including the HEVC codec (as libde265 or FFmpeg).

The messages “It is not of the right kind of document”, “Not supported file format” or similar may appear when the application itself or codec layer of operating system is outdated. The update should begin from the application - it should be updated before installing the newer version of operating system or appropriate package (for example, HEIF decoder in Windows).

If a HEIF picture is considered to be corrupted and there was an error while opening it (it depends on program used), one should look for box of type “ftyp”, whose ASCII code will be “ftyp”. Its HEX code will be “66 74 79 70”. Usually ftyp is on byte #4.

Sometimes, the exported files are not able to extract auxiliary images, which may contain bursts, or thumbnail, alpha planes or depth map. Use a HEIF tool that allows enumerating the content items properly. For dull or overly bright HDR or wide-gamut HEIF photos, use the Apple Photos application or any recent color-managed photo-editor, honoring of ICC profile. Also, if export rotates file sideways, using ImageMagick with -auto-orient parameter helps to orientate pictures properly.

Moreover, in case of transfers of pictures from iPhones as JPEG file, it is recommended to check Settings>Photos>Transfer to Mac or PC and choose the option 'Keep Originals'.

Security considerations

HEIC files lack macros, script or executable code embedded in documents, and consequently represent less threat in daily use than Microsoft Office files, JavaScript-equipped PDFs, or installation sets. There still may be a non-negligible danger - .heic file may be decoded with ISO BMFF parser and HEVC H.265 video decoder, which is subject to exploitation with the buggy implementation in ISO BMFF support, iOS and macOS operating system codecs, Windows codecs or decoders, browsers, ImageMagick, and libde265 in case of HEIC. Always parse the content from .heic only through updated, sandboxed program. Avoid using outdated, non-trusted HEVC coding libraries and packages.

One can find metadata such as GPS-coordinates, date-time stamp of photo taking moment, camera, its model, lens used, software version used, as well as possibly device IDs, in HEIC image file. Before publishing, scrub metadata with exiftool -all= file.heic.Copy Additionally try to ensure that location information is removed and keep a copy for yourself. On uploading services check file magic number in bytes offset 4, HEIF brand boxes and maximal file size before transcoding into other formats with libraries which are actively maintained. Online conversion may read both pixels themselves and metadata in addition; sensitive files ought to be first edited on local computer in Preview or Photos applications, or in programs like ImageMagick.

History and versions

The history of the HEIC compression format can be seen to be related back to the creation of the HEVC/H.265 standards in 2013 as a video encoding standard where the intraframe encoding was modified to make it a still image compression format. The creation of the HEIF format, ISO/IEC 23008-12, came from MPEG, which defined it as still image file format that would contain still images and still image sequence, along with other image media.

Nokia introduced HEIF files, including documentation and open-source tools to show it off as a still general container and not one just related to videos based on MP4 containers only. Apple introduced it broadly with the launch of iOS 11 and macOS High Sierra by choosing .heic format extension as a default for high efficiency camera photos taken with certain iPhone and iPad. Instead of providing HEIC support by building all HEIC based decoders with the HEVC video standard, Microsoft has offered only Windows HEIF Image and Video Extensions support with Windows 10 operating system.

ISO/IEC 23000-22, or Multimedia Application Format (MIAF), further defined the usage of certain HEIF and AVIF format files as interoperable by defining constraints for used brands, codecs and metadata. ISO/IEC 23008-12 standard is publicly available and had its last release in 2022. In the 2020s it has remained relevant since its generation and usage among Apple devices, it competes against AVIF, WebP and JPEG XL formats on the web usage market.

Related formats

The .JPG and .JPEG continue to be the most universally supported interchange formats: just about any browser, printer station, emailer and graphics suite renders them quickly enough. The HEIC file will yield smaller-sized pictures of cameras at similar levels of perceiving quality and contain greater internal structures, while still JPEG continues winning when universal compatibility counts more than others.

The use of PNG file format is lossless, can include transparency, is highly usable but less compact format compared to HEIC's HEVC compression for camera photographs. The WEBP supports lossless, lossy, transparency and animations but not widely supported on older web browsers. HEIC is commonly produced by iPhone cameras but it is an inappropriate choice for direct web use. AVIF (.avif) is another HEIF-based file format which uses compression from AV1 instead of from the HEVC file compression.

.HEIF - this general HEIF file extension does not guarantee HEVC coding. HEIC usually refers to this kind of coding within the HEIF files. HEICS contains HEIC images sequence and MOV files contain motion part of the live photographs. JXL file extension refers to JPEG XL format for extended usage.