public static bool ReshapeToPowersOf2AndSave(Stream input, int size, string outputFileName)
{
InitializeIL();
InitializeILU();
// load the image
ImageData data = new ImageData();
int imageID;
// create and bind a new image
Il.ilGenImages(1, out imageID);
Il.ilBindImage(imageID);
// create a temp buffer and copy the stream into it
byte[] buffer = new byte[size];
int bytesRead = 0, byteOffset = 0, bytes = buffer.Length;
do
{
bytesRead = input.Read(buffer, byteOffset, bytes);
bytes -= bytesRead;
byteOffset += bytesRead;
} while (bytes > 0 && bytesRead > 0);
Il.ilLoadL(Il.IL_TYPE_UNKNOWN, buffer, buffer.Length);
// check errors
int ilError = Il.ilGetError();
if (ilError != Il.IL_NO_ERROR)
{
throw new AxiomException("Error while loading image data: '{0}'", Ilu.iluErrorString(ilError));
}
// determine dimensions & compute powers-of-2 reshape if needed
int width = Il.ilGetInteger(Il.IL_IMAGE_WIDTH);
int height = Il.ilGetInteger(Il.IL_IMAGE_HEIGHT);
int newWidth = (int)Math.Pow(2, Math.Floor(Math.Log(width, 2)));
int newHeight = (int)Math.Pow(2, Math.Floor(Math.Log(height, 2)));
if (width != newWidth || height != newHeight)
{
// reshape
// set the scale function filter & scale
Ilu.iluImageParameter(Ilu.ILU_FILTER, Ilu.ILU_BILINEAR); // .ILU_SCALE_BSPLINE);
Ilu.iluScale(newWidth, newHeight, 1);
}
// save
Il.ilSetInteger(Il.IL_JPG_QUALITY, 50);
Il.ilSaveImage(outputFileName);
// drop image
Il.ilDeleteImages(1, ref imageID);
return(true);
}
/// <summary>
/// We use a separate method for this because calling iluScale directly inline
/// was failing on the release build, with the stack getting trashed.
/// My(jsw) theory is that there is some problem with the jit compiler, pinvoke,
/// or the combination of the two that was causing this problem.
/// </summary>
/// <param name="scaleX">destination size of the scale operation</param>
/// <param name="scaleY">destination size of the scale operation</param>
private void DoScale(int scaleX, int scaleY)
{
// set the scale function filter & scale
Ilu.iluImageParameter(Ilu.ILU_FILTER, Ilu.ILU_BILINEAR); // .ILU_SCALE_BSPLINE);
Ilu.iluScale(scaleX, scaleY, 1);
}