imageformats

.NET modules for decoding obscure graphics formats:

• .PPM, .PGM, .PBM (Netpbm images)
• .TGA (Targa)
• .PCX (ZSoft Paintbrush)
• .IFF (Amiga ILBM images)
• .SGI, .RGB, .BW (SGI images)
• .RAS (Sun raster images)
• .MAC (MacPaint)
• .CUT (Dr. Halo)
• .XPM (X Window PixMap)
• .DEEP (TVPaint IFF DEEP images)
• .FITS (experimental support)
• .DICOM (experimental support)
• .ART (AOL Johnson-Grace images)
• .PSP, .PSPIMAGE (Paint Shop Pro images)

Usage

Every decoder returns an ImageData object: a plain buffer of raw pixels, with no dependency on any particular imaging library. Hand the buffer to whichever library you prefer.

using DmitryBrant.ImageFormats;

// Detects the format automatically, and returns null if it isn't one we know.
ImageData image = Picture.Load("picture.tga");

The pixels in image.Data are stored top-down, one row after another, four bytes per pixel in blue, green, red, alpha order. (Read as a 32-bit little-endian integer, that's the usual packed ARGB layout.) This is the same layout as GDI+ Format32bppArgb, WIC/Direct2D B8G8R8A8, Avalonia's Bgra8888, and ImageSharp's Bgra32, so it can go straight into any of them:

// Avalonia
var bitmap = new WriteableBitmap(new PixelSize(image.Width, image.Height),
    new Vector(96, 96), PixelFormat.Bgra8888, AlphaFormat.Unpremul);
using (var buffer = bitmap.Lock())
    for (int y = 0; y < image.Height; y++)
        Marshal.Copy(image.Data, y * image.Stride, buffer.Address + (y * buffer.RowBytes), image.Stride);

// ImageSharp
var bitmap = Image.LoadPixelData<Bgra32>(image.Data, image.Width, image.Height);

// System.Drawing
var bitmap = new Bitmap(image.Width, image.Height, PixelFormat.Format32bppArgb);
var bits = bitmap.LockBits(new Rectangle(Point.Empty, bitmap.Size), ImageLockMode.WriteOnly, bitmap.PixelFormat);
for (int y = 0; y < image.Height; y++)
    Marshal.Copy(image.Data, y * image.Stride, bits.Scan0 + (y * bits.Stride), image.Stride);
bitmap.UnlockBits(bits);

A few source formats store their pixel data as an embedded image in some other well-known encoding, most notably DICOM files that wrap a JPEG. Rather than pull in a JPEG decoder, the library passes those bytes through untouched: image.IsEncoded is true, image.Data is null, and the encoded bytes are in image.EncodedData (with image.EncodedFormat naming the encoding) for you to decode yourself.

The ImageViewer project in this repository is a small Avalonia app that does all of the above; see its Interop.cs for a complete example.

Copyright 2013+ Dmitry Brant

https://dmitrybrant.com

License: MIT