Programmatically adding Images to RTF Document
I am trying to add a image to a RTF document which I am creating. I would prefer to not use 'copy/paste' methods (that involve pasting the image within a RichTextBox and then accessing the .RTF property) which purge the clipboard (as this will be a bother and confusion for my end users).
The code I have so far returns the string that needs to be inserted into the RTF document to print the image. The inputted image (located at $path) is usually in bmp or jpeg format, but at this stage I am not concerned with how the image is stored within the RTF only that i can get it to work.
public string GetImage(string path, int width, int height)
{
MemoryStream stream = new MemoryStream();
string newPath = Path.Combine(Environment.CurrentDirectory, path);
Image img = Image.FromFile(newPath);
img.Save(stream, System.Drawing.Imaging.ImageFormat.Png);
byte [] bytes = stream.ToArray();
string str = BitConverter.ToString(bytes, 0).Replace("-", string.Empty);
//string str = System.Text.Encoding.UTF8.GetString(bytes);
string mpic = @"{\pict\pngblip\picw" +
img.Width.ToString() + @"\pich" + img.Height.ToString() +
@"\picwgoa" + width.ToString() + @"\pichgoa" + height.ToString() +
@"\hex " + str + "}";
return mpic
}
However the problem is that this code does not work because as far as I can tell, the string str does not have the correct string conversion to work within the RTF.
Edit: My problem was missing a space after the \hex in @"\hex " and also not stripping out the "-" characters from the returned value of the BitConverter
Solution 1:
try these links
- Rich Text Format (RTF) Specification, version 1.6
- How can I insert an image into a RichTextBox?
- Insert Image into rtf document
you must change "picwgoa" to "picwgoal" and "pichgoa" to "pichgoal"
string mpic = @"{\pict\pngblip\picw" +
img.Width.ToString() + @"\pich" + img.Height.ToString() +
@"\picwgoal" + width.ToString() + @"\pichgoal" + height.ToString() +
@"\bin " + str + "}";
Here you have a list of the supported image formats
\emfblip Source of the picture is an EMF (enhanced metafile).
\pngblip Source of the picture is a PNG.
\jpegblip Source of the picture is a JPEG.
\shppict Specifies a Word 97-2000 picture. This is a destination control word.
\nonshppict Specifies that Word 97-2000 has written a {\pict destination that it will not read on input. This keyword is for compatibility with other readers.
\macpict Source of the picture is QuickDraw.
\pmmetafileN Source of the picture is an OS/2 metafile. The N argument identifies the metafile type. The N values are described in the \pmmetafile table below.
\wmetafileN Source of the picture is a Windows metafile. The N argument identifies the metafile type (the default is 1).
\dibitmapN Source of the picture is a Windows device-independent bitmap. The N argument identifies the bitmap type (must equal 0).The information to be included in RTF from a Windows device-independent bitmap is the concatenation of the BITMAPINFO structure followed by the actual pixel data.
\wbitmapN Source of the picture is a Windows device-dependent bitmap. The N argument identifies the bitmap type (must equal 0).The information to be included in RTF from a Windows device-dependent bitmap is the result of the GetBitmapBits function.
Solution 2:
Spent a day or so googling answers for this. Pieced together tidbits from all over stackoverflow and other sources. Feed this an image, it'll return the string you need to add to your richtextbox.rtf extension. The image width changes and needs to be calculated, the formula is given.
// RTF Image Format
// {\pict\wmetafile8\picw[A]\pich[B]\picwgoal[C]\pichgoal[D]
//
// A = (Image Width in Pixels / Graphics.DpiX) * 2540
//
// B = (Image Height in Pixels / Graphics.DpiX) * 2540
//
// C = (Image Width in Pixels / Graphics.DpiX) * 1440
//
// D = (Image Height in Pixels / Graphics.DpiX) * 1440
[Flags]
enum EmfToWmfBitsFlags
{
EmfToWmfBitsFlagsDefault = 0x00000000,
EmfToWmfBitsFlagsEmbedEmf = 0x00000001,
EmfToWmfBitsFlagsIncludePlaceable = 0x00000002,
EmfToWmfBitsFlagsNoXORClip = 0x00000004
}
const int MM_ISOTROPIC = 7;
const int MM_ANISOTROPIC = 8;
[DllImport("gdiplus.dll")]
private static extern uint GdipEmfToWmfBits(IntPtr _hEmf, uint _bufferSize,
byte[] _buffer, int _mappingMode, EmfToWmfBitsFlags _flags);
[DllImport("gdi32.dll")]
private static extern IntPtr SetMetaFileBitsEx(uint _bufferSize,
byte[] _buffer);
[DllImport("gdi32.dll")]
private static extern IntPtr CopyMetaFile(IntPtr hWmf,
string filename);
[DllImport("gdi32.dll")]
private static extern bool DeleteMetaFile(IntPtr hWmf);
[DllImport("gdi32.dll")]
private static extern bool DeleteEnhMetaFile(IntPtr hEmf);
public static string GetEmbedImageString(Bitmap image)
{
Metafile metafile = null;
float dpiX; float dpiY;
using (Graphics g = Graphics.FromImage (image))
{
IntPtr hDC = g.GetHdc ();
metafile = new Metafile (hDC, EmfType.EmfOnly);
g.ReleaseHdc (hDC);
}
using (Graphics g = Graphics.FromImage (metafile))
{
g.DrawImage (image, 0, 0);
dpiX = g.DpiX;
dpiY = g.DpiY;
}
IntPtr _hEmf = metafile.GetHenhmetafile ();
uint _bufferSize = GdipEmfToWmfBits (_hEmf, 0, null, MM_ANISOTROPIC,
EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
byte[] _buffer = new byte[_bufferSize];
GdipEmfToWmfBits (_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
IntPtr hmf = SetMetaFileBitsEx (_bufferSize, _buffer);
string tempfile = Path.GetTempFileName ();
CopyMetaFile (hmf, tempfile);
DeleteMetaFile (hmf);
DeleteEnhMetaFile (_hEmf);
var stream = new MemoryStream ();
byte[] data = File.ReadAllBytes (tempfile);
//File.Delete (tempfile);
int count = data.Length;
stream.Write (data, 0, count);
string proto = @"{\rtf1{\pict\wmetafile8\picw" + (int)( ( (float)image.Width / dpiX ) * 2540 )
+ @"\pich" + (int)( ( (float)image.Height / dpiY ) * 2540 )
+ @"\picwgoal" + (int)( ( (float)image.Width / dpiX ) * 1440 )
+ @"\pichgoal" + (int)( ( (float)image.Height / dpiY ) * 1440 )
+ " "
+ BitConverter.ToString(stream.ToArray()).Replace("-", "")
+ "}}";
return proto;
}
Solution 3:
Later visitors to this page (such as I was a few days ago) may find the following link useful: Convert an image into WMF with .NET
One will find that WordPad ignores any image not stored in the proper Windows MetaFile format. Thus, the previous example on this page will not show up at all (Even though it works just fine in OpenOffice and Word itself). The format that WordPad WILL support is:
{/pict/wmetafile8/picw[width]/pich[height]/picwgoal[scaledwidth]/pichgoal[scaledheight] [image-as-string-of-byte-hex-values]} (with terms in square brackets replaced with the appropriate data).
Getting the 'appropriate data' can be done by following the procedures in the above link. For those with python looking for a solution, here is the start of one (I believe some dpi/scaling issues remain). This requires PIL(or Pillow), ctypes, and clr (Python .NET). Use PIL/Pillow and open up the image first. Here I have it open as "canv":
from ctypes import *
import clr
clr.AddReference("System.IO")
clr.AddReference("System.Drawing")
from System import IntPtr
from System.Drawing import SolidBrush
from System.Drawing import Color
from System.Drawing import Imaging
from System.Drawing import Graphics
from System.IO import FileStream
from System.IO import FileMode
from System.IO import MemoryStream
from System.IO import File
def byte_to_hex(bytefile):
acc = ''
b = bytefile.read(1)
while b:
acc+=("%02X" % ord(b))
b = bytefile.read(1)
return acc.strip()
#... in here is some code where 'canv' is created as the PIL image object, and
#... 'template' is defined as a string with placeholders for picw, pich,
#... picwgoal, pichgoal, and the image data
mfstream = MemoryStream()
offscrDC = Graphics.FromHwndInternal(IntPtr.Zero)
imgptr = offscrDC.GetHdc()
mfile = Imaging.Metafile(mfstream, imgptr, Imaging.EmfType.EmfOnly)
gfx = Graphics.FromImage(mfile)
width,height = canv.size
pixels = canv.load()
for x in range(width):
for y in range(height):
_r,_g,_b = pixels[x, y]
c = Color.FromArgb(_r, _g, _b)
brush = SolidBrush(c)
gfx.FillRectangle(brush, x, y, 1, 1)
gfx.Dispose()
offscrDC.ReleaseHdc()
_hEmf = mfile.GetHenhmetafile()
GdipEmfToWmfBits = windll.gdiplus.GdipEmfToWmfBits
_bufferSize = GdipEmfToWmfBits(
int(str(_hEmf)),
c_uint(0),
None,
c_int(8), # MM_ANISOTROPIC
c_uint(0x00000000)) # Default flags
_buffer = c_int * _bufferSize
_buffer = _buffer(*[0 for x in range(_bufferSize)])
GdipEmfToWmfBits( int(str(_hEmf)),
c_uint(_bufferSize),
_buffer,
c_int(8), # MM_ANISOTROPIC
c_uint(0x00000000) ) # Default flags
hmf = windll.gdi32.SetMetaFileBitsEx(c_uint(_bufferSize), _buffer)
windll.gdi32.CopyMetaFileA(int(str(hmf)), "temp.wmf")
windll.gdi32.DeleteMetaFile(int(str(hmf)))
windll.gdi32.DeleteEnhMetaFile(int(str(_hEmf)))
mfstream.Close()
imgstr = open("temp.wmf", 'rb')
imgstr = byte_to_hex(imgstr)
with open('script-out.rtf','wb') as outf:
template = template % (str(_cx),str(_cy),str(15*_cx),str(15*_cy),imgstr)
outf.write(template)