/// <summary>
/// Resizes an image by the specified scale factors using the specified sampling mode.
/// </summary>
/// <param name="image">Image to resize.</param>
/// <param name="scaleX">Scale factor to apply in X direction.</param>
/// <param name="scaleY">Scale factor to apply in Y direction.</param>
/// <param name="mode">Sampling mode for sampling of pixels.</param>
/// <returns>Returns a new image scaled by the specified scale factors.</returns>
public static Shared <Image> Scale(this Image image, float scaleX, float scaleY, SamplingMode mode)
{
if (scaleX == 0.0 || scaleY == 0.0)
{
throw new System.Exception("Unexpected scale factors");
}
if (image.PixelFormat == PixelFormat.Gray_16bpp)
{
throw new System.NotSupportedException(
"Scaling 16bpp images is not currently supported. " +
"Convert to a supported format such as color or 8bpp grayscale first.");
}
int dstWidth = (int)(image.Width * scaleX);
int dstHeight = (int)(image.Height * scaleY);
using (var bitmap = new Bitmap(dstWidth, dstHeight))
{
using (var graphics = Graphics.FromImage(bitmap))
{
graphics.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
switch (mode)
{
case SamplingMode.Point:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighSpeed;
break;
case SamplingMode.Bilinear:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
break;
case SamplingMode.Bicubic:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
break;
}
graphics.ScaleTransform(scaleX, scaleY);
using (var managedimg = image.ToManagedImage())
{
graphics.DrawImage(managedimg, new Point(0, 0));
}
return(ImagePool.GetOrCreate(bitmap));
}
}
}
/// <summary>
/// Draws a circle centered at the specified pixel (p0) with the specified radius
/// </summary>
/// <param name="image">Image to draw on</param>
/// <param name="p0">Pixel coordinates for center of circle</param>
/// <param name="radius">Radius of the circle</param>
/// <param name="color">Color to use for drawing</param>
/// <param name="width">Width of line</param>
public static void DrawCircle(this Image image, Point p0, int radius, Color color, int width)
{
Bitmap bm = image.ToManagedImage(false);
var graphics = Graphics.FromImage(bm);
var pen = new Pen(new SolidBrush(color));
pen.Width = width;
graphics.DrawEllipse(pen, p0.X - radius, p0.Y - radius, 2 * radius, 2 * radius);
}
/// <summary>
/// Draws a line from point p0 to p1 in pixel coordinates on the image
/// </summary>
/// <param name="image">Image to draw on</param>
/// <param name="p0">Pixel coordinates for start of line</param>
/// <param name="p1">Pixel coordinates for end of line</param>
/// <param name="color">Color to use for drawing</param>
/// <param name="width">Width of line</param>
public static void DrawLine(this Image image, Point p0, Point p1, Color color, int width)
{
Bitmap bm = image.ToManagedImage(false);
var graphics = Graphics.FromImage(bm);
var pen = new Pen(new SolidBrush(color));
pen.Width = width;
graphics.DrawLine(pen, p0, p1);
}
/// <summary>
/// Draws a rectangle at the specified pixel coordinates on the image
/// </summary>
/// <param name="image">Image to draw on</param>
/// <param name="rect">Pixel coordinates for rectangle</param>
/// <param name="color">Color to use for drawing</param>
/// <param name="width">Width of line</param>
public static void DrawRectangle(this Image image, Rectangle rect, Color color, int width)
{
Bitmap bm = image.ToManagedImage(false);
var graphics = Graphics.FromImage(bm);
var pen = new Pen(new SolidBrush(color));
pen.Width = width;
graphics.DrawRectangle(pen, rect);
}
/// <summary>
/// Resizes an image by the specified scale factors using the specified sampling mode
/// </summary>
/// <param name="image">Image to resize</param>
/// <param name="xScale">Scale factor to apply in X direction</param>
/// <param name="yScale">Scale factor to apply in Y direction</param>
/// <param name="mode">Sampling mode for sampling of pixels</param>
/// <returns>Returns a new image scaled by the specified scale factors</returns>
public static Shared <Image> Scale(this Image image, float xScale, float yScale, SamplingMode mode)
{
if (xScale == 0.0 || yScale == 0.0)
{
throw new System.Exception("Unexpected scale factors");
}
int dstWidth = (int)(image.Width * xScale);
int dstHeight = (int)(image.Height * yScale);
var bitmap = new Bitmap(dstWidth, dstHeight);
var graphics = Graphics.FromImage(bitmap);
graphics.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
switch (mode)
{
case SamplingMode.Point:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighSpeed;
break;
case SamplingMode.Bilinear:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
break;
case SamplingMode.Bicubic:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
break;
}
graphics.ScaleTransform(xScale, yScale);
graphics.DrawImage(image.ToManagedImage(), new Point(0, 0));
return(ImagePool.GetOrCreate(bitmap));
}
/// <summary>
/// Flips an image along a specified axis
/// </summary>
/// <param name="image">Image to flip</param>
/// <param name="mode">Axis along which to flip</param>
/// <returns>A new flipped image</returns>
public static Shared <Image> Flip(this Image image, FlipMode mode)
{
var bitmap = new Bitmap(image.Width, image.Height);
var graphics = Graphics.FromImage(bitmap);
switch (mode)
{
case FlipMode.AlongHorizontalAxis:
graphics.TranslateTransform(0.0f, image.Height - 1);
graphics.ScaleTransform(1.0f, -1.0f);
break;
case FlipMode.AlongVerticalAxis:
graphics.TranslateTransform(image.Width - 1, 0.0f);
graphics.ScaleTransform(-1.0f, 1.0f);
break;
}
graphics.DrawImage(image.ToManagedImage(), new Point(0, 0));
return(ImagePool.GetOrCreate(bitmap));
}
/// <summary>
/// Rotates an image
/// </summary>
/// <param name="image">Image to rotate</param>
/// <param name="angleInDegrees">Number of degrees to rotate in counter clockwise direction</param>
/// <param name="mode">Pixel resampling method</param>
/// <returns>Rotated image</returns>
public static Shared <Image> Rotate(this Image image, float angleInDegrees, SamplingMode mode)
{
float ca = (float)System.Math.Cos(angleInDegrees * System.Math.PI / 180.0f);
float sa = (float)System.Math.Sin(angleInDegrees * System.Math.PI / 180.0f);
float minx = 0.0f;
float miny = 0.0f;
float maxx = 0.0f;
float maxy = 0.0f;
float x = image.Width - 1;
float y = 0.0f;
float nx = (x * ca) - (y * sa);
float ny = (x * sa) + (y * ca);
if (nx < minx)
{
minx = nx;
}
if (nx > maxx)
{
maxx = nx;
}
if (ny < miny)
{
miny = ny;
}
if (ny > maxy)
{
maxy = ny;
}
x = image.Width - 1;
y = image.Height - 1;
nx = (x * ca) - (y * sa);
ny = (x * sa) + (y * ca);
if (nx < minx)
{
minx = nx;
}
if (nx > maxx)
{
maxx = nx;
}
if (ny < miny)
{
miny = ny;
}
if (ny > maxy)
{
maxy = ny;
}
x = 0.0f;
y = image.Height - 1;
nx = (x * ca) - (y * sa);
ny = (x * sa) + (y * ca);
if (nx < minx)
{
minx = nx;
}
if (nx > maxx)
{
maxx = nx;
}
if (ny < miny)
{
miny = ny;
}
if (ny > maxy)
{
maxy = ny;
}
int dstWidth = (int)(maxx - minx + 1);
int dstHeight = (int)(maxy - miny + 1);
var bitmap = new Bitmap(dstWidth, dstHeight);
var graphics = Graphics.FromImage(bitmap);
graphics.CompositingMode = System.Drawing.Drawing2D.CompositingMode.SourceCopy;
switch (mode)
{
case SamplingMode.Point:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighSpeed;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.NearestNeighbor;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighSpeed;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighSpeed;
break;
case SamplingMode.Bilinear:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
break;
case SamplingMode.Bicubic:
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
break;
}
graphics.TranslateTransform(-minx, -miny);
graphics.RotateTransform(angleInDegrees);
graphics.DrawImage(image.ToManagedImage(), new Point(0, 0));
return(ImagePool.GetOrCreate(bitmap));
}
/// <summary>
/// Flips an image along a specified axis
/// </summary>
/// <param name="image">Image to flip</param>
/// <param name="mode">Axis along which to flip</param>
/// <returns>A new flipped image</returns>
public static Shared <Image> Flip(this Image image, FlipMode mode)
{
if (image.PixelFormat == PixelFormat.Gray_16bpp)
{
// We can't handle this through GDI.
Shared <Image> dstImage = ImagePool.GetOrCreate(image.Width, image.Height, image.PixelFormat);
unsafe
{
int srcBytesPerPixel = PixelFormatHelper.GetBytesPerPixel(image.PixelFormat);
int dstBytesPerPixel = PixelFormatHelper.GetBytesPerPixel(dstImage.Resource.PixelFormat);
byte *srcRow = (byte *)image.ImageData.ToPointer();
byte *dstRow = (byte *)dstImage.Resource.ImageData.ToPointer();
int ystep = dstImage.Resource.Stride;
if (mode == FlipMode.AlongHorizontalAxis)
{
dstRow += dstImage.Resource.Stride * (image.Height - 1);
ystep = -dstImage.Resource.Stride;
}
int xstep = dstBytesPerPixel;
int xoffset = 0;
if (mode == FlipMode.AlongVerticalAxis)
{
xoffset = dstBytesPerPixel * (dstImage.Resource.Width - 1);
xstep = -dstBytesPerPixel;
}
for (int i = 0; i < image.Height; i++)
{
byte *srcCol = srcRow;
byte *dstCol = dstRow + xoffset;
for (int j = 0; j < image.Width; j++)
{
((ushort *)dstCol)[0] = ((ushort *)srcCol)[0];
srcCol += srcBytesPerPixel;
dstCol += xstep;
}
srcRow += image.Stride;
dstRow += ystep;
}
}
return(dstImage);
}
else
{
var bitmap = new Bitmap(image.Width, image.Height);
var graphics = Graphics.FromImage(bitmap);
switch (mode)
{
case FlipMode.AlongHorizontalAxis:
graphics.TranslateTransform(0.0f, image.Height - 1);
graphics.ScaleTransform(1.0f, -1.0f);
break;
case FlipMode.AlongVerticalAxis:
graphics.TranslateTransform(image.Width - 1, 0.0f);
graphics.ScaleTransform(-1.0f, 1.0f);
break;
}
graphics.DrawImage(image.ToManagedImage(), new Point(0, 0));
return(ImagePool.GetOrCreate(bitmap));
}
}
