Openize.Heic

Openize.Heic is an open source SDK implementing the ISO/IEC 23008-12:2017 HEIF file format decoder.

It is written from scratch and has a plain C# API to enable a simple integration into other software.

Supported features

Openize.Heic has support for:

• HEIC coded static images;
  • I slices;
  • 4:2:0, 4:2:2 and 4:4:4 chroma subsampling.
• HEIC coded animations that use several I‑slices;
• multiple images in a file;
• alpha channels, depth maps, thumbnails, auxiliary images;
• correct color transform according to embedded color profiles;
• image transformations (crop, mirror, rotate), overlay images.

Openize.Heic doesn't support:

• HDR images;
• reading EXIF and XMP metadata;
• color transform according to EXIF contained color profiles;
• HEIC coded animations that use P and B‑slices;
• deblocking filter.

Usage examples

Read .heic file to int array with Argb32 data

using (var fs = new FileStream("filename.heic", FileMode.Open))
{
    HeicImage image = HeicImage.Load(fs);
    int[] pixels = image.GetInt32Array(Heic.Decoder.PixelFormat.Argb32);
}

Convert .heic file to .png

using (var fs = new FileStream("filename.heic", FileMode.Open))
{
    HeicImage image = HeicImage.Load(fs);
     
    var pixels = image.GetByteArray(Heic.Decoder.PixelFormat.Bgra32);
    var width = (int)image.Width;
    var height = (int)image.Height;
     
    var wbitmap = new WriteableBitmap(width, height, 72, 72, PixelFormats.Bgra32, null);
    var rect = new Int32Rect(0, 0, width, height);
    wbitmap.WritePixels(rect, pixels, 4 * width, 0);
    
    using FileStream saveStream = new FileStream("output.png", FileMode.OpenOrCreate);
    PngBitmapEncoder encoder = new PngBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(wbitmap));
    encoder.Save(saveStream);
}

Convert .heic file to .jpg

using (var fs = new FileStream("filename.heic", FileMode.Open))
{
    HeicImage image = HeicImage.Load(fs);
     
    var pixels = image.GetByteArray(Heic.Decoder.PixelFormat.Bgra32);
    var width = (int)image.Width;
    var height = (int)image.Height;
     
    var wbitmap = new WriteableBitmap(width, height, 72, 72, PixelFormats.Bgra32, null);
    var rect = new Int32Rect(0, 0, width, height);
    wbitmap.WritePixels(rect, pixels, 4 * width, 0);
    
    using FileStream saveStream = new FileStream("output.jpg", FileMode.OpenOrCreate);
    JpegBitmapEncoder encoder = new JpegBitmapEncoder();
    encoder.Frames.Add(BitmapFrame.Create(wbitmap));
    encoder.Save(saveStream);
}

Convert .heic collection to a set of .png files

using (var fs = new FileStream("filename.heic", FileMode.Open))
{
    HeicImage image = HeicImage.Load(fs);

    foreach (var key in image.Frames.Keys)
    {
        var width = (int)image.Frames[key].Width;
        var height = (int)image.Frames[key].Height;
        var pixels = image.Frames[key].GetByteArray(Openize.Heic.Decoder.PixelFormat.Bgra32);

        var wbitmap = new WriteableBitmap(width, height, 72, 72, PixelFormats.Bgra32, null);
        var rect = new Int32Rect(0, 0, width, height);
        wbitmap.WritePixels(rect, pixels, 4 * width, 0);

        using FileStream saveStream = new FileStream("output"+key+".png", FileMode.OpenOrCreate);
        PngBitmapEncoder encoder = new PngBitmapEncoder();
        encoder.Frames.Add(BitmapFrame.Create(wbitmap));
        encoder.Save(saveStream);
    }
}

Documentation

All public classes, methods and properties are documented in corresponding API_README:

• /Openize.Heic.Decoder/docs/API_README.md for Openize.Heic.Decoder;
• /Openize.IsoBmff/docs/API_README.md for Openize.IsoBmff.

HeicImage

Methods

Name	Type	Description	Parameters	Notes
Load	HeicImage	Reads the file meta data and creates a class object for further decoding of the file contents.	Stream stream - File stream.	This operation does not decode pixels. Use the default frame methods GetByteArray or GetInt32Array afterwards in order to decode pixels.
CanLoad	bool	Checks if the stream can be read as a heic image. Returns true if file header contains heic signarure, false otherwise	Stream stream - File stream.

Properties

Name	Type	Description
Frames	Dictionary<uint, HeicImageFrame>	Dictionary of public Heic image frames with access by identifier.
AllFrames	Dictionary<uint, HeicImageFrame>	Dictionary of all Heic image frames with access by identifier.
DefaultImage	HeicImageFrame	Returns the default image frame, which is specified in meta data.

HeicImageFrame

Methods

Name	Type	Description	Parameters
GetByteArray	byte[]	Get pixel data in the format of byte array. Each three or four bytes (the count depends on the pixel format) refer to one pixel left to right top to bottom line by line.	PixelFormat pixelFormat - Pixel format that defines the order of colors and the presence of alpha byte. Rectangle boundsRectangle - Bounds of the requested area.
GetInt32Array	int[]	Get pixel data in the format of integer array. Each int value refers to one pixel left to right top to bottom line by line.	PixelFormat pixelFormat - Pixel format that defines the order of colors. Rectangle boundsRectangle - Bounds of the requested area.
GetTextData	string	Get frame text data. Exists only for mime frame types.

Properties

Name	Type	Description
ImageType	ImageFrameType	Type of an image frame content.
Width	uint	Width of the image frame in pixels.
Height	uint	Height of the image frame in pixels.
HasAlpha	bool	Indicates the presence of transparency of transparency layer. True if frame is linked with alpha data frame, false otherwise.
IsHidden	bool	Indicates the fact that frame is marked as hidden. True if frame is hidden, false otherwise.
IsImage	bool	Indicates the fact that frame contains image data. True if frame is image, false otherwise.
IsDerived	bool	Indicates the fact that frame contains image transform data and is inherited from another frame(-s). True if frame is derived, false otherwise.
DerivativeType	BoxType?	Indicates the type of derivative content if the frame is derived.
AuxiliaryReferenceType	AuxiliaryReferenceType	Indicates the type of auxiliary reference layer if the frame type is auxiliary.
NumberOfChannels	byte	Number of channels with color data.
BitsPerChannel	byte[]	Bits per channel with color data.

License

Openize.HEIC is available under Openize License.

Caution

Openize does not and cannot grant You a patent license for the utilization of HEVC/H.265 image compression/decompression technologies.

Openize.HEIC uses Openize.IsoBmff that is distributed under MIT License.

OSS Notice

Sample files used for tests and located in the "./Openize.Heic.Tests/TestsData/samples/nokia" folder belong to Nokia Technologies and are used according to Nokia High-Efficiency Image File Format (HEIF) License

Licensed Field means the non-commercial purposes of evaluation, testing and academic research in each non-commercial case to use, run, modify (in a way that still complies with the Specification) and copy the Software to (a) generate, using one or more encoded pictures as inputs, a file complying with the Specification and including the one or more encoded pictures that were given as inputs; and/or (b) read a file complying with the Specification, resulting into one or more encoded pictures included in the file as outputs.