papnkukn/wmf

The library supports reading and writing WMF files. Source code is written in pure .NET from scratch following the Windows Metafile Format Specification.

Windows Metafile Library

Note: this project moved from https://wmf.codeplex.com/

Project Description

The library supports reading and writing WMF files. Source code is written in pure .NET from scratch following the Windows Metafile Format Specification.

Technical Information

• Name: Window Metafile Format (WMF)
• File extension: .wmf, .emf
• Mime type: image/x-wmf, image/x-emf
• Classification: vector/raster image
• Identifier: D7 CD C6 9A (first four bytes)
• Documentation: WMF Specification

Why WMF?

WMF is all about records - recorded sequence of actions. As opposite to other vector or raster image formats that define final image appearance, WMF contains intermediate states. Those states can be modified at specific working stage or can be "played" back to render an image. From other point of view WMF file natively contains "undo" history.

Another advantage of WMF is to support both vector and raster elements in one file. Disadvantage are lack of features (e.g. no element grouping like layers or trees), 16-bit limitations, bad extensibility due to old image format.

WMF can be replaced by EPS but since Windows has good integration with the WMF it is still useful in some cases: clipboard - transfering images with copy/paste, Clip Art images from MS Office are WMF, etc.

Notice

This library does not fully implement Windows Metafile Format Specification. Current library version (v0.3) supports only basic WMF records but the source code is well structured so the missing records can easily be implemented if needed. I am not planning to develop other WMF records as the current version fulfills my requirements for another project.

Examples

Create a simple WMF image with rectangle

var wmf = new WmfDocument();
wmf.Width = 1000;
wmf.Height = 1000;
wmf.Format.Unit = 288;
wmf.AddPolyFillMode(PolyFillMode.WINDING);
wmf.AddCreateBrushIndirect(Color.Blue, BrushStyle.BS_SOLID);
wmf.AddSelectObject(0);
wmf.AddCreatePenIndirect(Color.Black, PenStyle.PS_SOLID, 1);
wmf.AddSelectObject(1);
wmf.AddRectangle(100, 100, 800, 800);
wmf.AddDeleteObject(0);
wmf.AddDeleteObject(1);
wmf.Save(path);

Read a WMF file and display human-readable values for analysis

WmfDocument wmf = new WmfDocument();
wmf.Load(path);

string dump = wmf.Dump();
Console.WriteLine(dump);

Read records from WMF file

WmfDocument wmf = new WmfDocument();
wmf.Load(path);

foreach (var record in wmf.Records)
{
  if (record is WmfCreateBrushIndirectRecord)
  {
    var brush = record as WmfCreateBrushIndirectRecord;
    Console.WriteLine("Color: " + brush.Color);
    Console.WriteLine("Style: " + brush.Style);
    Console.WriteLine("Hatch: " + brush.Hatch);
  }
  else if (record is WmfRectangleRecord)
  {
    var rectangle = record as WmfRectangleRecord;
    //Do something with rectangle...
  }
}

wmf's Issues

Invalid DIB size calculation

DeviceIndependentBitmap currently doesn't take into account the color palette stored in the DIB, which makes the size calculation incorrect. Currently it reads:

• read 40-byte header
• read (seemingly properly calculated amount of) data bytes into Data

But it should:

• read 40-byte header
• read (header.ColorsUsed ?? 1 << header.BitCount) * 4 bytes into Colors
• read same amount of data into Data

Here's a compressed example of a file that reads incorrectly by the library: _bm0.zip.

Update link to WMF specification in README

The link to the WMF specification in the README appears to be dead. Could you consider updating it with a live link?

Some options I found:

• loc.gov

• microsoft from here

record size issue

MS-WMF.pdf

Hello, i think this code has some issue. According to the wmf format specification:

1. For the record type META_STRETCHBLT and META_DIBSTRETCHBLT, no matter the record with bitmap data or not, the data member "SrcHeight" and "SrcWidth" should exist.
   therefor, the file "WmfStretchBltRecord.cs" (line 76, 80) and "WmfDIBStretchBltRecord.cs" (line 76, 80) is wrong.
   If without bitmap data, the record length should be 28, not 24. and at line 80, need not this condition "if (!isWithoutBitmap)".
   2.For the record type META_STRETCHDIB, wmf format specification doesn't refer to "without bitmap data", so, i think line 82 in file "WmfDIBStretchBltRecord.cs" is unnecessary, this record type must be 28 bytes and some DIB data bytes.