I load image from disc:
var img = Image.FromFile("foo");
var bmp = new Bitmap(img);
I wrote method to split image into pieces:
public static IEnumerable<Bitmap> VerticalSplit(this Bitmap src, int pixels)
{
var bmps = new List<Bitmap>();
for (int i = 0; i < src.Width; i+=pixels)
{
var dst = new Bitmap(pixels, src.Height);
using (var grD = Graphics.FromImage(dst))
{
grD.DrawImage(src, new Rectangle(i, 0, pixels, src.Height), new Rectangle(0,0,pixels,src.Height), GraphicsUnit.Pixel);
bmps.Add(dst);
}
}
return bmps;
}
And this is the usage:
var parts = bmp.VerticalSplit(10);
for (int i = 0; i < parts.Count(); i++)
{
parts[i].Save(#"output/" + i + ".jpg");
}
The problem is that every image except 1 is blank. Why does that happen?
See DrawImage, which has a signature of:
public void DrawImage (System.Drawing.Image image,
System.Drawing.Rectangle destRect, System.Drawing.Rectangle srcRect,
System.Drawing.GraphicsUnit srcUnit);
Note that the second parameter is "destRect", and the third parameter is "srcRect". Your code has the destination and source rectangles BACKWARDS.
Change:
grD.DrawImage(src, new Rectangle(i, 0, pixels, src.Height), new Rectangle(0,0,pixels,src.Height), GraphicsUnit.Pixel);
To:
grD.DrawImage(src, new Rectangle(0,0,pixels,src.Height), new Rectangle(i, 0, pixels, src.Height), GraphicsUnit.Pixel);
Related
I keep getting this error of 'System.Runtime.InteropServices.ExternalException' on line 70 "img3.Save(finalImage, System.Drawing.Imaging.ImageFormat.Jpeg);". Originally I had a program that stitched two photos together that worked fine, but I wanted the two images to be the same size (300 pixles by 300 pixles) so I inserted a method:
public static Image resizeImage(Image imgToResize, Size size)
{
return (Image)(new Bitmap(imgToResize, size));
}
and in my CombineImages method put:
img = resizeImage(img, new Size(300, 300));
but now I am getting an error. Here is my code:
private void cmdCombine_Click(object sender, EventArgs e)
{
//Change the path to location where your images are stored.
DirectoryInfo directory = new DirectoryInfo(#"C:\Users\Elder Zollinger\Desktop\Images");
if (directory != null)
{
FileInfo[] files = directory.GetFiles();
CombineImages(files);
}
}
private void CombineImages(FileInfo[] files)
{
//change the location to store the final image.
string finalImage = #"C:\Users\Elder Zollinger\Desktop\Images\Final.jpg";
List<int> imageHeights = new List<int>();
int nIndex = 0;
int width = 0;
foreach (FileInfo file in files)
{
Image img = Image.FromFile(file.FullName);
img = resizeImage(img, new Size(300, 300));
imageHeights.Add(img.Height);
width += img.Width;
img.Dispose();
}
imageHeights.Sort();
int height = imageHeights[imageHeights.Count - 1];
Bitmap img3 = new Bitmap(width, height);
Graphics g = Graphics.FromImage(img3);
g.Clear(SystemColors.AppWorkspace);
foreach (FileInfo file in files)
{
Image img = Image.FromFile(file.FullName);
if (nIndex == 0)
{
g.DrawImage(img, new Point(0, 0));
nIndex++;
width = img.Width;
}
else
{
g.DrawImage(img, new Point(width, 0));
width += img.Width;
}
img.Dispose();
}
g.Dispose();
img3.Save(finalImage, System.Drawing.Imaging.ImageFormat.Jpeg);
img3.Dispose();
imageLocation.Image = Image.FromFile(finalImage);
}
public static Image resizeImage(Image imgToResize, Size size)
{
return (Image)(new Bitmap(imgToResize, size));
}
}
}
It is likely that the image format of the uploaded image cannot be converted directly to Jpeg. One thing we do when resizing is actually draw the image to a new Graphics instance as follows. Note that the first 2 lines attempt to get the pixel and image formats directly from the original image instance - you may have issues with CMYK and images with a transparency layer (GIF/PNG).
var pixelFormat = imgToResize.PixelFormat;
var imageFormat = imgToResize.RawFormat;
Bitmap b = new Bitmap(newWidth.Value, newHeight.Value, pixelFormat);
Graphics g = Graphics.FromImage(b);
g.SmoothingMode = SmoothingMode.AntiAlias;
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.PixelOffsetMode = PixelOffsetMode.HighQuality;
g.DrawImage(imgToResize, (float)-0.5, (float)-0.5, newWidth.Value + 1, newHeight.Value + 1);
g.Dispose();
b.Save(stream, imageFormat);
I have an array which consists in PixelData extracted from a Dicom Image.
Here's the code:
byte[] bytes = img.PixelData.GetFrame(0).Data; // img is the Dicom Image
int count = bytes.Length / 2;
ushort[] words = new ushort[count];
for (int i = 0, p = 0; i < count; i++, p += 2)
{
words[i] = BitConverter.ToUInt16(bytes, p);
}
pixels16 = words.ToList(); //pixels16 contains now the PixelData for the Grayscale image
Now, here's my question, how do I render that into a Picturebox??
My code for converting Bitmaps from Format16bppGrayScale to Format8bppIndexed format. PictureBox can easy show this format. (If you want, you can use different palette).
public Bitmap Gray16To8bppIndexed(Bitmap BmpIn)
{
if (BmpIn.PixelFormat != PixelFormat.Format16bppGrayScale)
throw new BadImageFormatException();
byte[] ImageData = new byte[BmpIn.Width * BmpIn.Height * 2];
Rectangle Re = new Rectangle(0, 0, BmpIn.Width, BmpIn.Height);
BitmapData BmpData = BmpIn.LockBits(Re, ImageLockMode.ReadOnly, BmpIn.PixelFormat);
Marshal.Copy(BmpData.Scan0, ImageData, 0, ImageData.Length);
BmpIn.UnlockBits(BmpData);
byte[] ImageData2 = new byte[BmpIn.Width * BmpIn.Height];
for (long i = 0; i < ImageData2.LongLength; i++)
ImageData2[i] = ImageData[i * 2 + 1];
ImageData = null;
Bitmap BmpOut = new Bitmap(BmpIn.Width, BmpIn.Height, PixelFormat.Format8bppIndexed);
BmpData = BmpOut.LockBits(Re, ImageLockMode.WriteOnly, BmpOut.PixelFormat);
Marshal.Copy(ImageData2, 0, BmpData.Scan0, ImageData2.Length);
BmpOut.UnlockBits(BmpData);
ImageData2 = null;
BmpData = null;
ColorPalette GrayPalette = BmpOut.Palette;
Color[] GrayColors = GrayPalette.Entries;
for (int i = 0; i < GrayColors.Length; i++)
GrayColors[GrayColors.Length - 1 - i] = Color.FromArgb(i, i, i);
BmpOut.Palette = GrayPalette;
return BmpOut;
}
Well, I don't know the specifics, because it depends on how you really want to go about it (if performance is important, you need to create your own subclass of Bitmap, but otherwise, Bitmap.SetPixel would work fine).
But essentially, you need to shove those pixels into a Bitmap, then set the picture box's image to that bitmap, like:
Bitmap bitmap = new Bitmap(width, height);
for(int y = 0;y < height;y++)
for(int x = 0;x < width;x++)
bitmap.SetPixel(x,y, Color.fromRGB(/* unpack your R,G,B channel of your pixel here */);
pictureBox.Image = bitmap;
You can utilize the AForge .NET Framework, which is a great .NET library for image processing. The built-in .NET Picturebox could not nativley display images with System.Drawing.Imaging.PixelFormat.Format16bppGrayScale, but the AForge library has its own Picturebox control, check this out. It expects a .NET Image.
You can include AForge to your project easily with NuGet:
Install-Package AForge.Controls
Install-Package AForge.Imaging
Or just
Install-Package AForge
Example code below:
//SOME BYTES
//Load here the DICOM image
int width=640, height=480;
int numberOfPixels = width*height;
byte[] source = new byte[2*numberOfPixels];
//With AFORGE
var image = AForge.Imaging.UnmanagedImage.Create(width, height, System.Drawing.Imaging.PixelFormat.Format16bppGrayScale);
IntPtr ptrToImage = image.ImageData;
//Copies the bytes from source to the image
//System.Runtime.InteropServices
Marshal.Copy(source, 0, ptrToImage,numberOfPixels);
//WITH .NET
System.Drawing.Bitmap bitmapImage = new System.Drawing.Bitmap(width, height, System.Drawing.Imaging.PixelFormat.Format16bppGrayScale);
var imageData = bitmapImage.LockBits(new System.Drawing.Rectangle(0, 0, width, height), System.Drawing.Imaging.ImageLockMode.ReadWrite, System.Drawing.Imaging.PixelFormat.Format16bppGrayScale);
Marshal.Copy(source, 0, imageData.Scan0, numberOfPixels);
bitmapImage.UnlockBits(imageData);
Got this idea from a friend. The inputImage.ImageSource property is a 2D array with grayscale pixel values.
Bitmap grayscaleImage = new Bitmap(inputImage.ImageSource);
for (int x = 0; x < grayscaleImage.Width; x++)
{
for (int y = 0; y < grayscaleImage.Height; y++)
{
byte[,] tempMatrix = inputImage.ImageGrayscale;
byte temp = tempMatrix[x, y];
Color tempColor = Color.FromArgb(255, temp, temp, temp);
grayscaleImage.SetPixel(x, y, tempColor);
}
}
picboxDisplay.Image = grayscaleImage;
I want to merge two pictures in my C# program.
the first one is any picture in grayscale mode, and the second one is like in this picture:
Both of the pictures/images have the same size, and this is my code:
Bitmap first = new Bitmap (picturebox1.image);
Bitmap second = new Bitmap (picturebox2.image);
Bitmap result = new Bitmap (first.width, first.height);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.Flush();
g.DrawImageUnscaled(second, 0, 0);
g.Flush();
picturebox3.image = result;
I can join those picture, but the result has smaller size than the two originals (both pictures have same size). Could anyone give me some suggestions?
Additionally, I want the result picture has condition like this :
if the edge pixel in 2nd picture dropped to the bright side at the 1st one, it will be dark, otherwise when the edge dropped to the dark side, it will be bright (seem glow).
so the text will be semi transparent.
Here's an example of the results I want.
Could anyone give some suggestions please?
It was for joining
Bitmap first = new Bitmap (picturebox1.Image);
Bitmap second = new Bitmap (picturebox2.Image);
Bitmap result = new Bitmap (first.Width+first.Width, first.Height);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.DrawImageUnscaled(second,first.Width, 0);
Try this for merging one on top another . set alpha by yourself ( red: U can use BitMap.MakeTransParent if u not want alpha)
public Bitmap SetImageOpacity(Image image, float opacity)
{
try
{
//create a Bitmap the size of the image provided
Bitmap bmp = new Bitmap(image.Width, image.Height);
//create a graphics object from the image
using (Graphics gfx = Graphics.FromImage(bmp))
{
//create a color matrix object
ColorMatrix matrix = new ColorMatrix();
//set the opacity
matrix.Matrix33 = opacity;
//create image attributes
ImageAttributes attributes = new ImageAttributes();
//set the color(opacity) of the image
attributes.SetColorMatrix(matrix, ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
//now draw the image
gfx.DrawImage(image, new Rectangle(0, 0, bmp.Width, bmp.Height), 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, attributes);
}
return bmp;
}
catch (Exception ex)
{
return null;
}
}
private void button1_Click(object sender, EventArgs e)
{
Bitmap first = new Bitmap(pictureBox1.Image);
Bitmap second = SetImageOpacity(pictureBox2.Image, 0.5f);
//Bitmap result = new Bitmap(first.Width, first.Height);
//fix :
Bitmap result = new Bitmap(Math.Max(first.Width,second.Width), Math.Max(first.Height,second.Height));
Console.WriteLine(first.Width);
Graphics g = Graphics.FromImage(result);
g.DrawImageUnscaled(first, 0, 0);
g.DrawImageUnscaled(second, 0, 0);
pictureBox3.Image = result;
result.Save("result.jpg" );
}
}
}
And Coming For watermark why not you want to use Drawstring with alpha
here is article for all these http://www.codeproject.com/Articles/5034/How-to-implement-Alpha-blending
You need to include the System.Drawing.Imaging namespace to make this code work.
Go through following code:
private void CombineImages(FileInfo[] files)
{
//change the location to store the final image.
string finalImage = #"C:\\MyImages\\FinalImage.jpg";
List imageHeights = new List();
int nIndex = 0;
int width = 0;
foreach (FileInfo file in files)
{
Image img = Image.FromFile(file.FullName);
imageHeights.Add(img.Height);
width += img.Width;
img.Dispose();
}
imageHeights.Sort();
int height = imageHeights[imageHeights.Count - 1];
Bitmap img3 = new Bitmap(width, height);
Graphics g = Graphics.FromImage(img3);
g.Clear(SystemColors.AppWorkspace);
foreach (FileInfo file in files)
{
Image img = Image.FromFile(file.FullName);
if (nIndex == 0)
{
g.DrawImage(img, new Point(0, 0));
nIndex++;
width = img.Width;
}
else
{
g.DrawImage(img, new Point(width, 0));
width += img.Width;
}
img.Dispose();
}
g.Dispose();
img3.Save(finalImage, System.Drawing.Imaging.ImageFormat.Jpeg);
img3.Dispose();
imageLocation.Image = Image.FromFile(finalImage);
}
Follow Link:
http://www.niteshluharuka.com/2012/08/combine-several-images-to-form-a-single-image-using-c/
This codeproject article shows how to watermark an image with text as well as another image.
In summary, what you have to do is draw your watermark image over the image with the desired transparency.
I'm trying to create an 8-bit image with a solid background color. It seems like it should be pretty straight forward but the details on the file list it as 32-bit color depth. What am I missing?
public void CreateImage()
{
var bmpOut = new Bitmap(300, 300);
var g = Graphics.FromImage(bmpOut);
g.FillRectangle(new SolidBrush(Color.Gray), 0, 0, 300, 300);
var stream = new MemoryStream();
bmpOut.Save(stream, GetPngCodecInfo(), GetEncoderParameters());
bmpOut.Save(#"C:\image.png", GetPngCodecInfo(), GetEncoderParameters());
}
public EncoderParameters GetEncoderParameters()
{
var parameters = new EncoderParameters();
parameters.Param[0] = new EncoderParameter(Encoder.ColorDepth, 8);
return parameters;
}
public ImageCodecInfo GetPngCodecInfo()
{
var encoders = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo codecInfo = null;
foreach (var imageCodecInfo in encoders)
{
if (imageCodecInfo.FormatID != ImageFormat.Png.Guid)
continue;
codecInfo = imageCodecInfo;
break;
}
return codecInfo;
}
Use this constructor to specify a pixel format : http://msdn.microsoft.com/en-us/library/3z132tat.aspx
Since you cannot create a Graphics from an indexed pixel format, you can only write raw pixels to a 8-bit image.
Bitmap bitmap = new Bitmap(32, 32, PixelFormat.Format8bppIndexed);
var bitmapData = bitmap.LockBits(new Rectangle(Point.Empty, bitmap.Size), ImageLockMode.ReadWrite, bitmap.PixelFormat);
Random random=new Random();
byte[] buffer=new byte[bitmap.Width*bitmap.Height];
random.NextBytes(buffer);
Marshal.Copy(buffer,0,bitmapData.Scan0,buffer.Length);
bitmap.UnlockBits(bitmapData);
bitmap.Save("test.bmp",ImageFormat.Bmp);
You can either use such code on WinForms : http://www.codeproject.com/Articles/17162/Fast-Color-Depth-Change-for-Bitmaps
Or if you can reference this class from WPF it will be much easier :
http://msdn.microsoft.com/en-us/library/system.windows.media.imaging.formatconvertedbitmap(v=vs.85).aspx
You could also create the image at a higher bit rate and then convert it to 8 bits just before saving. This would allow you to use a Graphics context when creating the image. See this question for suggestions on how to convert to 8 bits:C# - How to convert an Image into an 8-bit color Image?
ImageExtensions.cs
using System.Runtime.InteropServices;
using System.Linq;
using System.Drawing.Imaging;
using System.Drawing;
using System;
public static partial class ImageExtensions {
public static ColorPalette ToGrayScale(this ColorPalette palette) {
var entries=palette.Entries;
for(var i=entries.Length; i-->0; entries[i]=entries[i].ToGrayScale())
;
return palette;
}
public static Color ToGrayScale(this Color color, double[] luminance=null) {
var list=(luminance??new[] { 0.2989, 0.5870, 0.1140 }).ToList();
var channel=new[] { color.R, color.G, color.B };
var c=(byte)Math.Round(list.Sum(x => x*channel[list.IndexOf(x)]));
return Color.FromArgb(c, c, c);
}
public static Bitmap To8bppIndexed(this Bitmap original) {
var rect=new Rectangle(Point.Empty, original.Size);
var pixelFormat=PixelFormat.Format8bppIndexed;
var destination=new Bitmap(rect.Width, rect.Height, pixelFormat);
using(var source=original.Clone(rect, PixelFormat.Format32bppArgb)) {
var destinationData=destination.LockBits(rect, ImageLockMode.WriteOnly, pixelFormat);
var sourceData=source.LockBits(rect, ImageLockMode.ReadOnly, source.PixelFormat);
var destinationSize=destinationData.Stride*destinationData.Height;
var destinationBuffer=new byte[destinationSize];
var sourceSize=sourceData.Stride*sourceData.Height;
var sourceBuffer=new byte[sourceSize];
Marshal.Copy(sourceData.Scan0, sourceBuffer, 0, sourceSize);
source.UnlockBits(sourceData);
destination.Palette=destination.Palette.ToGrayScale();
var list=destination.Palette.Entries.ToList();
for(var y=destination.Height; y-->0; ) {
for(var x=destination.Width; x-->0; ) {
var pixelIndex=y*destination.Width+x;
var sourceIndex=4*pixelIndex;
var color=
Color.FromArgb(
sourceBuffer[0+sourceIndex],
sourceBuffer[1+sourceIndex],
sourceBuffer[2+sourceIndex],
sourceBuffer[3+sourceIndex]
).ToGrayScale();
destinationBuffer[pixelIndex]=(byte)list.IndexOf(color);
}
}
Marshal.Copy(destinationBuffer, 0, destinationData.Scan0, destinationSize);
destination.UnlockBits(destinationData);
}
return destination;
}
}
Call bmpOut=bmpOut.To8bppIndexed(); before you it save to file.
I need to convert bitonal (black and white) TIFF files into another format for display by a web browser, currently we're using JPGs, but the format isn't crucial. From reading around .NET doesn't seem to easily support writing bitonal images, so we're ending up with ~1MB files instead of ~100K ones. I'm considering using ImageMagick to do this, but ideally i'd like a solution which doesn't require this if possible.
Current code snippet (which also does some resizing on the image):
using (Image img = Image.FromFile(imageName))
{
using (Bitmap resized = new Bitmap(resizedWidth, resizedHeight)
{
using (Graphics g = Graphics.FromImage(resized))
{
g.DrawImage(img, new Rectangle(0, 0, resized.Width, resized.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel);
}
resized.Save(outputFilename, System.Drawing.Imaging.ImageFormat.Jpeg);
}
}
Is there any way to achieve this?
Thanks.
I believe the problem can be solved by checking that resized bitmap is of PixelFormat.Format1bppIndexed. If it's not, you should convert it to 1bpp bitmap and after that you can save it as black and white png without problems.
In other words, you should use following code instead of resized.Save(outputFilename, System.Drawing.Imaging.ImageFormat.Jpeg);
if (resized.PixelFormat != PixelFormat.Format1bppIndexed)
{
using (Bitmap bmp = convertToBitonal(resized))
bmp.Save(outputFilename, System.Drawing.Imaging.ImageFormat.Png);
}
else
{
resized.Save(outputFilename, System.Drawing.Imaging.ImageFormat.Png);
}
I use following code for convertToBitonal :
private static Bitmap convertToBitonal(Bitmap original)
{
int sourceStride;
byte[] sourceBuffer = extractBytes(original, out sourceStride);
// Create destination bitmap
Bitmap destination = new Bitmap(original.Width, original.Height,
PixelFormat.Format1bppIndexed);
destination.SetResolution(original.HorizontalResolution, original.VerticalResolution);
// Lock destination bitmap in memory
BitmapData destinationData = destination.LockBits(
new Rectangle(0, 0, destination.Width, destination.Height),
ImageLockMode.WriteOnly, PixelFormat.Format1bppIndexed);
// Create buffer for destination bitmap bits
int imageSize = destinationData.Stride * destinationData.Height;
byte[] destinationBuffer = new byte[imageSize];
int sourceIndex = 0;
int destinationIndex = 0;
int pixelTotal = 0;
byte destinationValue = 0;
int pixelValue = 128;
int height = destination.Height;
int width = destination.Width;
int threshold = 500;
for (int y = 0; y < height; y++)
{
sourceIndex = y * sourceStride;
destinationIndex = y * destinationData.Stride;
destinationValue = 0;
pixelValue = 128;
for (int x = 0; x < width; x++)
{
// Compute pixel brightness (i.e. total of Red, Green, and Blue values)
pixelTotal = sourceBuffer[sourceIndex + 1] + sourceBuffer[sourceIndex + 2] +
sourceBuffer[sourceIndex + 3];
if (pixelTotal > threshold)
destinationValue += (byte)pixelValue;
if (pixelValue == 1)
{
destinationBuffer[destinationIndex] = destinationValue;
destinationIndex++;
destinationValue = 0;
pixelValue = 128;
}
else
{
pixelValue >>= 1;
}
sourceIndex += 4;
}
if (pixelValue != 128)
destinationBuffer[destinationIndex] = destinationValue;
}
Marshal.Copy(destinationBuffer, 0, destinationData.Scan0, imageSize);
destination.UnlockBits(destinationData);
return destination;
}
private static byte[] extractBytes(Bitmap original, out int stride)
{
Bitmap source = null;
try
{
// If original bitmap is not already in 32 BPP, ARGB format, then convert
if (original.PixelFormat != PixelFormat.Format32bppArgb)
{
source = new Bitmap(original.Width, original.Height, PixelFormat.Format32bppArgb);
source.SetResolution(original.HorizontalResolution, original.VerticalResolution);
using (Graphics g = Graphics.FromImage(source))
{
g.DrawImageUnscaled(original, 0, 0);
}
}
else
{
source = original;
}
// Lock source bitmap in memory
BitmapData sourceData = source.LockBits(
new Rectangle(0, 0, source.Width, source.Height),
ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
// Copy image data to binary array
int imageSize = sourceData.Stride * sourceData.Height;
byte[] sourceBuffer = new byte[imageSize];
Marshal.Copy(sourceData.Scan0, sourceBuffer, 0, imageSize);
// Unlock source bitmap
source.UnlockBits(sourceData);
stride = sourceData.Stride;
return sourceBuffer;
}
finally
{
if (source != original)
source.Dispose();
}
}
Have you tried saving using the Image.Save overload with Encoder parameters?
Like the Encoder.ColorDepth Parameter?
Trying jaroslav's suggestion for color depth doesn't work:
static void Main(string[] args)
{
var list = ImageCodecInfo.GetImageDecoders();
var jpegEncoder = list[1]; // i know this is the jpeg encoder by inspection
Bitmap bitmap = new Bitmap(500, 500);
Graphics g = Graphics.FromImage(bitmap);
g.DrawRectangle(new Pen(Color.Red), 10, 10, 300, 300);
var encoderParams = new EncoderParameters();
encoderParams.Param[0] = new EncoderParameter(Encoder.ColorDepth, 2);
bitmap.Save(#"c:\newbitmap.jpeg", jpegEncoder, encoderParams);
}
The jpeg is still a full color jpeg.
I don't think there is any support for grayscale jpeg in gdi plus. Have you tried looking in windows imaging component?
http://www.microsoft.com/downloads/details.aspx?FamilyID=8e011506-6307-445b-b950-215def45ddd8&displaylang=en
code example: http://www.codeproject.com/KB/GDI-plus/windows_imaging.aspx
wikipedia: http://en.wikipedia.org/wiki/Windows_Imaging_Component
This is an old thread. However, I'll add my 2 cents.
I use AForge.Net libraries (open source)
use these dlls. Aforge.dll, AForge.Imaging.dll
using AForge.Imaging.Filters;
private void ConvertBitmap()
{
markedBitmap = Grayscale.CommonAlgorithms.RMY.Apply(markedBitmap);
ApplyFilter(new FloydSteinbergDithering());
}
private void ApplyFilter(IFilter filter)
{
// apply filter
convertedBitmap = filter.Apply(markedBitmap);
}
Have you tried PNG with 1 bit color depth?
To achieve a size similar to a CCITT4 TIFF, I believe your image needs to use a 1-bit indexed pallette.
However, you can't use the Graphics object in .NET to draw on an indexed image.
You will probably have to use LockBits to manipulate each pixel.
See Bob Powell's excellent article.