/// <summary>
/// Creates a copy of the given bitmap after cropping white pixels from top and bottom of image.
/// Requires a 1bitPerPixel image format, and must be a regular sized fax bitmap (1728 pixels wide).
/// after rotation using the supplied intermediate resolution
/// and Angle. Positive Angle is Clockwise. The resulting image has the same horizonatal
/// and vertical resolution as the given page, but geometry may have changed (height and width).
/// </summary>
/// <param name="bmp">The Bitmap to rotate</param>
/// <param name="intermediateResolution">The intermediate resolution to use.</param>
/// <param name="rotationAngle">The angle to rotate the image</param>
/// <returns></returns>
public static Bitmap CreateCopyCrop(Bitmap bmp)
{
PageInfo bmpinfo = new PageInfo(bmp);
if (bmpinfo.WidthPixels != ImageUtility.FAX_TIF_HOR_PX && bmpinfo.HorizontalResolution != ImageUtility.FAX_TIF_HOR_RES)
{
throw new Exception("Bitmap is not the correct size for cropping.");
}
if (bmp.PixelFormat != PixelFormat.Format1bppIndexed)
{
throw new Exception("Bitmap is not the correct pixel format for cropping.");
}
// Lock source bitmap in memory
BitmapData sourceData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadOnly, PixelFormat.Format1bppIndexed);
// Copy image data to binary array
int imageSize = sourceData.Stride * sourceData.Height;
byte[] sourceBuffer = new byte[imageSize];
Marshal.Copy(sourceData.Scan0, sourceBuffer, 0, imageSize);
// Unlock source bitmap
bmp.UnlockBits(sourceData);
int firstDataRow = BitmapHelper.ScanForFirstNonWhiteRow(sourceBuffer, sourceData.Stride, true, false);
int lastDataRow = BitmapHelper.ScanForFirstNonWhiteRow(sourceBuffer, sourceData.Stride, false, true);
int totalRows = lastDataRow - firstDataRow + 1;
int newHeight = 0;
var quality = FaxQuality.Undefined;
var paper = PaperSize.Undefined;
if (bmp.VerticalResolution == ImageUtility.FAX_TIF_VER_RES_HI)
{
if (totalRows <= ImageUtility.FAX_TIF_VER_PX_LTR_HI)
{
newHeight = ImageUtility.FAX_TIF_VER_PX_LTR_HI; paper = PaperSize.Letter;
}
else if (totalRows <= ImageUtility.FAX_TIF_VER_PX_LGL_HI)
{
newHeight = ImageUtility.FAX_TIF_VER_PX_LGL_HI; paper = PaperSize.Legal;
}
else
{
newHeight = ImageUtility.FAX_TIF_VER_PX_LGL_HI; paper = PaperSize.Legal;
}
quality = FaxQuality.Fine;
}
if (bmp.VerticalResolution == ImageUtility.FAX_TIF_VER_RES_LOW)
{
if (totalRows <= ImageUtility.FAX_TIF_VER_PX_LTR_LOW)
{
newHeight = ImageUtility.FAX_TIF_VER_PX_LTR_LOW; paper = PaperSize.Letter;
}
else if (totalRows <= ImageUtility.FAX_TIF_VER_PX_LGL_LOW)
{
newHeight = ImageUtility.FAX_TIF_VER_PX_LGL_LOW; paper = PaperSize.Legal;
}
else
{
newHeight = ImageUtility.FAX_TIF_VER_PX_LGL_LOW; paper = PaperSize.Legal;
}
quality = FaxQuality.Normal;
}
//Make sure the first data row does not go negative.
firstDataRow = Math.Max(0, firstDataRow - ((newHeight - totalRows) / 2));
//Make sure last does not extend out of the original document range.
lastDataRow = Math.Min(Math.Max(0, bmp.Height - 1), Math.Max(0, firstDataRow + newHeight - 1));
totalRows = lastDataRow - firstDataRow + 1;
var startindex = firstDataRow * sourceData.Stride;
var length = totalRows * sourceData.Stride;
var croppedBitmap = BitmapHelper.CreateBitMap(paper, quality, PixelFormat.Format1bppIndexed);
// Lock destination bitmap in memory
BitmapData destinationData = croppedBitmap.LockBits(new Rectangle(0, 0, croppedBitmap.Width, croppedBitmap.Height), ImageLockMode.WriteOnly, PixelFormat.Format1bppIndexed);
// Copy binary image data to destination bitmap
Marshal.Copy(sourceBuffer, startindex, destinationData.Scan0, length);
// Unlock destination bitmap
croppedBitmap.UnlockBits(destinationData);
return(croppedBitmap);
}
