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ASCII art with C#

By , 30 Jan 2005
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Sample Image - ascii_art_with_c_.jpg

Introduction

Behind the scenes: I like C# and I like ASCII art. So I asked myself if somebody has written some image to ASCII application in C#. I Googled but found nothing. I did image manipulation stuff for my company and so I decided to build a basic image-to-ASCII conversion library in C#.

You can see a running sample here.

Step 1: The Upload Form.

To keep it quite simple, I just check the content type and let my library do the rest.

if(File1.PostedFile.ContentType=="image/gif" ||
    File1.PostedFile.ContentType=="image/jpg" ||
    File1.PostedFile.ContentType=="image/jpeg" ||
    File1.PostedFile.ContentType=="image/pjpeg" ||
    File1.PostedFile.ContentType=="image/bmp")
   {
        Output.Text = "<xmp>" +
        StaticDust.AsciiArt.ConvertImage(
         File1.PostedFile.InputStream) +
        "</xmp>";
   }
   else
   {
        ...

Step 2: The Library

The first thing I do is of course load the image:

Image _img = Image.FromStream(stream);
Bitmap _image = 
 new Bitmap(_img, new Size(_img.Width, _img.Height));
_img.Dispose();

Next I grayscale the image - you'll see later why.

Rectangle bounds = 
 new Rectangle(0, 0, _image.Width, _image.Height);

ColorMatrix _matrix = new ColorMatrix();
_matrix[0,0] = 1/3f;
_matrix[0,1] = 1/3f;
_matrix[0,2] = 1/3f;
_matrix[1,0] = 1/3f;
_matrix[1,1] = 1/3f;
_matrix[1,2] = 1/3f;
_matrix[2,0] = 1/3f;
_matrix[2,1] = 1/3f;
_matrix[2,2] = 1/3f;

ImageAttributes _attributes = 
 new ImageAttributes();
_attributes.SetColorMatrix(_matrix);

Graphics gphGrey = Graphics.FromImage(_image);
gphGrey.DrawImage(_image, 
 bounds, 
 0, 
 0, 
 _image.Width, 
 _image.Height,
 GraphicsUnit.Pixel, 
 _attributes);

gphGrey.Dispose();

O.K. Now, we get to the interesting part.

for(int h=0; h<_image.Height/10; h++)
{
    int _startY = (h*10);

    for(int w=0; w<_image.Width/5; w++)
    {
         int _startX = (w*5);
         int _allBrightness = 0;
         ...

I loop through the image's pixels and because I don't want one ASCII character per pixel, I take one per 10/5. To let every pixel influence the resulting ASCII char, I loop them and calculate the brightness of the amount.

for(int y=0; y<10; y++)
{
    for(int x=0; x<10; x++)
    {
        int _cY = y + _startY;
        int _cX = x + _startX;
        try
        {
            Color _c = _image.GetPixel(_cX, _cY);
            int _b = (int)(_c.GetBrightness() * 10);
            _allBrightness = (_allBrightness + _b);
        }
        catch
        {
            _allBrightness = (_allBrightness + 10);
        }
        ...

Finally, I append different ASCII characters based on the calculated amount:

int _sb = (_allBrightness/10);
if(_sb<25)
{
    _asciiart.Append("#");
}
else if(_sb<30)
{
    ...

That's all

Thanks to The Code Project and Chris Maunder, newtelligence and greetings to all C# coders out there.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

A list of licenses authors might use can be found here

About the Author

Daniel Fisher (lennybacon)
Web Developer
Germany Germany
Daniel Fisher is co-founder of devcoach. He supports since 1997 customers and projects in Germany and throughout Europe. As a consultant and developer he has worked several years on projects for insurance companies, distributors, mobile communications hardware, construction supplies and various other companies of different branches. He has a strong emphasis on service-orientation, agile methods, the web and data access. He is a frequent speaker on national and international software developer conferences in Germany, England and Poland. Daniel is actively contributing the software developer community as lead of a user group and organizer of the biggest regional software developer community event. You can read his blog by visiting lennybacon.com.

Comments and Discussions

 
Generaladd in install PinmemberPyro Joe22-Jan-05 16:49 
GeneralRe: add in install PinmemberDaniel Fisher (lennybacon)22-Jan-05 23:23 

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