Tuesday, March 18, 2008

Rotate Image

·

protected void Page_Load(object sender, EventArgs e)
{
Bitmap b = new Bitmap(Server.MapPath("3.jpg"));
b = RotateBitmap(45, b);
b.Save(Server.MapPath("6.jpg"), ImageFormat.Jpeg);
}
public Bitmap RotateBitmap(float Angle, Bitmap bm_in)
{
try
{
float wid = bm_in.Width;
float hgt = bm_in.Height;
Point[] corners = { new Point(0, 0), new Point(int.Parse(wid.ToString()), 0), new Point(0, int.Parse(hgt.ToString())), new Point(int.Parse(wid.ToString()), int.Parse(hgt.ToString())) };
int cx = int.Parse(wid.ToString()) / 2;
int cy = int.Parse(hgt.ToString()) / 2;
long i;
for (i = 0; i <= 3; i++)
{
corners[i].X -= Convert.ToInt32(cx.ToString());
corners[i].Y -= Convert.ToInt32(cy.ToString());
}

float theta = (float)(Angle * Math.PI / 180.0);
float sin_theta = (float)Math.Sin(theta);
float cos_theta = (float)Math.Cos(theta);
float X;
float Y;
for (i = 0; i <= 3; i++)
{
X = corners[i].X;
Y = corners[i].Y;
corners[i].X = (int)(X * cos_theta + Y * sin_theta);
corners[i].Y = (int)(-X * sin_theta + Y * cos_theta);
}

float xmin = corners[0].X;
float ymin = corners[0].Y;
for (i = 1; i <= 3; i++)
{
if (xmin > corners[i].X)
xmin = corners[i].X;
if (ymin > corners[i].Y)
ymin = corners[i].Y;
}
for (i = 0; i <= 3; i++)
{
corners[i].X -= int.Parse(xmin.ToString());
corners[i].Y -= int.Parse(ymin.ToString());
}

Bitmap bm_out = new Bitmap((int)(-2 * xmin), (int)(-2 * ymin));
Graphics gr_out = Graphics.FromImage(bm_out);
// ERROR: Not supported in C#: ReDimStatement
Point[] temp = new Point[3];
if (corners != null)
{
Array.Copy(corners, temp, Math.Min(corners.Length, temp.Length));
}
corners = temp;
gr_out.DrawImage(bm_in, corners);
return bm_out;
}
catch (Exception ex)
{
string s = ex.Message;
return bm_in;
}
}

2 comments:

Apurv said...
June 20, 2008 at 11:19 AM  
This comment has been removed by the author.
apurv said...
June 20, 2008 at 11:25 AM  


catch (Exception ex)
{
string s = ex.Message;
return bm_in;
}

as far i can note, the above code will catch aal exceptions, but eill ex.Message; pop-up any message window ?

another issue that i would like to ask is, for this code to execute, do the client need a fast internet connection ?