public static byte[] VisualCaptcha(string source)
{
try
{
System.Random r = new System.Random();
int w = 350, h = 75;
string family = "Arial Rounded MT Bold";
using (var bmp = new System.Drawing.Bitmap(w, h
, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
{
int m = 0, nm = 0;
System.Drawing.Color tc;
using (var g = System.Drawing.Graphics.FromImage(bmp))
{
g.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.Clear(System.Drawing.Color.White);
System.Drawing.SizeF size;
m = r.Next() % 9 + 1;
nm = r.Next() % 3;
tc = System.Drawing.Color.FromArgb(255, 255, 255);
size = g.MeasureString(source
, new System.Drawing.Font(family, h * 1.2f, System.Drawing.FontStyle.Bold)
, new System.Drawing.SizeF(w * 1F, h * 1F));
using (var brush = new System.Drawing.Drawing2D.LinearGradientBrush(
new System.Drawing.Rectangle(0, 0, w, h)
, System.Drawing.Color.Black
, System.Drawing.Color.Black, 45, false))
{
System.Drawing.Drawing2D.ColorBlend blend =
new System.Drawing.Drawing2D.ColorBlend(6);
for (var i = 0; i < 6; i++)
{
blend.Positions[i] = i * (1 / 5F); blend.Colors[i] = r.RandomColor(255, 64, 128);
}
brush.InterpolationColors = blend;
for (int wave = 0; wave < 2; wave++)
{
int min = (15 + wave * 20);
System.Drawing.PointF[] pt = new System.Drawing.PointF[] {
new System.Drawing.PointF(16f, (float)r.Next(min, min + 10))
, new System.Drawing.PointF(240f, (float)r.Next(min + 10, min + 20))
};
System.Collections.Generic.List <System.Drawing.PointF> PointList =
new System.Collections.Generic.List <System.Drawing.PointF>();
float curDist = 0, distance = 0;
for (int i = 0; i < pt.Length - 1; i++)
{
System.Drawing.PointF ptA = pt[i], ptB = pt[i + 1];
float deltaX = ptB.X - ptA.X, deltaY = ptB.Y - ptA.Y;
curDist = 0;
distance = (float)System.Math.Sqrt(System.Math.Pow(deltaX, 2) + System.Math.Pow(deltaY, 2));
while (curDist < distance)
{
curDist++;
float offsetX = (float)((double)curDist / (double)distance * (double)deltaX);
float offsetY = (float)((double)curDist / (double)distance * (double)deltaY);
PointList.Add(new System.Drawing.PointF(ptA.X + offsetX, ptA.Y + offsetY));
}
}
for (int i = 0; i < PointList.Count - 24; i = i + 24)
{
float x1 = PointList[i].X, y1 = PointList[i].Y, x2 = PointList[i + 24].X, y2 = PointList[i + 24].Y;
float angle = (float)((System.Math.Atan2(y2 - y1, x2 - x1) * 180 / 3.14159265));
g.TranslateTransform(x1, y1);
g.RotateTransform(angle);
int pm = r.Next() % 2 + 1;
System.Drawing.Point[] p1 = new System.Drawing.Point[] {
new System.Drawing.Point(0, 0)
, new System.Drawing.Point(3, -3 * pm)
, new System.Drawing.Point(6, -4 * pm)
, new System.Drawing.Point(9, -3 * pm)
, new System.Drawing.Point(12, 0)
, new System.Drawing.Point(15, 3 * pm)
, new System.Drawing.Point(18, 4 * pm)
, new System.Drawing.Point(21, 3 * pm)
, new System.Drawing.Point(24, 0)
};
using (var path = new System.Drawing.Drawing2D.GraphicsPath()) g.DrawLines(new System.Drawing.Pen(brush, 2f), p1);
g.RotateTransform(-angle);
g.TranslateTransform(-x1, -y1);
}
}
using (var path = new System.Drawing.Drawing2D.GraphicsPath())
{
System.Drawing.PointF[] points = new System.Drawing.PointF[] { };
if (m == 1 || m == 2 || m == 3) // star trek inverse
{
path.AddString(source
, new System.Drawing.FontFamily(family), 1, h * 0.75F
, new System.Drawing.PointF((w - size.Width) / 2F
, (h * 0.9F - size.Height) / 2F)
, System.Drawing.StringFormat.GenericTypographic);
points = new System.Drawing.PointF[] {
new System.Drawing.PointF(0, 0)
, new System.Drawing.PointF(w, 0)
, new System.Drawing.PointF(w * 0.2F, h)
, new System.Drawing.PointF(w * 0.8F, h)
};
}
else if (m == 4 || m == 5) // star trek
{
path.AddString(source, new System.Drawing.FontFamily(family), 1, h * 0.75F
, new System.Drawing.PointF((w - size.Width) / 2F
, (h * 1.2F - size.Height) / 2F + 2F)
, System.Drawing.StringFormat.GenericTypographic);
points = new System.Drawing.PointF[] { new System.Drawing.PointF(w * 0.2F, 0)
, new System.Drawing.PointF(w * 0.8F, 0)
, new System.Drawing.PointF(0, h)
, new System.Drawing.PointF(w, h) };
}
else if (m == 6 || m == 7) // grow from left
{
path.AddString(source, new System.Drawing.FontFamily(family), 1, h * 0.75F
, new System.Drawing.PointF((w * 1.15F - size.Width) / 2F
, (h - size.Height) / 2F)
, System.Drawing.StringFormat.GenericTypographic);
points = new System.Drawing.PointF[] {
new System.Drawing.PointF(0, h * 0.25F)
, new System.Drawing.PointF(w, 0)
, new System.Drawing.PointF(0, h * 0.75F)
, new System.Drawing.PointF(w, h)
};
}
else if (m == 8 || m == 9) // grow from right
{
path.AddString(source, new System.Drawing.FontFamily(family), 1, h * 0.75F
, new System.Drawing.PointF((w * 0.85F - size.Width) / 2F
, (h - size.Height) / 2F)
, System.Drawing.StringFormat.GenericTypographic);
points = new System.Drawing.PointF[] {
new System.Drawing.PointF(w * 0.1F, 0)
, new System.Drawing.PointF(w * 0.9F, h * 0.25F)
, new System.Drawing.PointF(w * 0.1F, h)
, new System.Drawing.PointF(w * 0.9F, h * 0.75F)
};
}
path.Warp(points, new System.Drawing.RectangleF(0, 0, w, h));
g.FillPath(System.Drawing.Brushes.White, path);
g.DrawPath(new System.Drawing.Pen(brush, 2F), path);
}
}
}
using (var thumb = new System.Drawing.Bitmap(128, 40
, System.Drawing.Imaging.PixelFormat.Format32bppArgb))
{
using (var g = System.Drawing.Graphics.FromImage(thumb))
{
g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
System.Drawing.Rectangle tr = new System.Drawing.Rectangle(0, 0, thumb.Width, thumb.Height);
g.DrawImage(bmp, tr);
g.DrawRectangle(
new System.Drawing.Pen(System.Drawing.Brushes.White)
, new System.Drawing.Rectangle(0, 0, 127, 39));
}
using (var ms = new System.IO.MemoryStream())
{
((System.Drawing.Image)thumb).Save(ms
, System.Drawing.Imaging.ImageFormat.Png);
return(ms.ToArray());
}
}
}
}
catch { return(null); }
}