private void pbPicture_Click(object sender, System.EventArgs e)
{
if (tiff == IntPtr.Zero)
{
return;
}
DateTime dtStart = DateTime.Now;
Random rnd = new Random();
// these are the grayscale LUT limits of rescale on click
int min = rnd.Next(0, 20);
int max = rnd.Next(50, 100);
// get actual bitmap data of the Bitmap object
BitmapData bmpData = ((Bitmap)pbPicture.Image).LockBits(
new Rectangle(0, 0, pbPicture.Image.Width, pbPicture.Image.Height),
ImageLockMode.ReadWrite,
PixelFormat.Format8bppIndexed);
tbLastScan0Ptr.Text = bmpData.Scan0.ToString();
// and free the previously allocated memory
LibTIFF._free(bmpData.Scan0);
((Bitmap)pbPicture.Image).UnlockBits(bmpData);
// dispose object and collect garbage (paranoia?... might be useful when dealing with huge files!)
pbPicture.Image.Dispose();
GC.Collect();
// set new image: same file, differently contrasted
pbPicture.Image = GetBitmapFromTIFFHandle(tiff, (ushort)min, (ushort)max);
tbContrastingTime.Text = ((ulong)((TimeSpan)(DateTime.Now - dtStart)).TotalMilliseconds).ToString();
}
private void btnCloseTIFF_Click(object sender, System.EventArgs e)
{
if (tiff == IntPtr.Zero)
{
return;
}
// reset handle, text fields
LibTIFF.Close(tiff);
tiff = (IntPtr)0;
tbTIFFPtr.Text = tiff.ToString();
tbRasterScanlineSize.Text = "";
tbScanlineSize.Text = "";
tbImageDimensions.Text = "";
tbTileDimensions.Text = "";
tbBitsPerSample.Text = "";
tbRowsPerStrip.Text = "";
tbSamplesPerPixel.Text = "";
tbInitialScan0Ptr.Text = "";
tbLastScan0Ptr.Text = "";
tbContrastingTime.Text = "";
// free bitmat data
BitmapData bmpData = ((Bitmap)pbPicture.Image).LockBits(
new Rectangle(0, 0, pbPicture.Image.Width, pbPicture.Image.Height),
ImageLockMode.ReadWrite,
PixelFormat.Format8bppIndexed);
LibTIFF._free(bmpData.Scan0);
((Bitmap)pbPicture.Image).UnlockBits(bmpData);
// dispose and clear Bitmap object
pbPicture.Image.Dispose();
pbPicture.Image = null;
}
private void tbCreateTIFF_Click(object sender, System.EventArgs e)
{
if (sfdCreateTIFF.ShowDialog() != DialogResult.OK)
{
return;
}
DateTime startTime = DateTime.Now;
// image size
int width = 1024 * Convert.ToInt16(tbSizeFactorX.Text);
int height = 1024 * Convert.ToInt16(tbSizeFactorY.Text);
short rowsPerStrip = (short)height;
// create file
IntPtr newTiff = LibTIFF.Open(sfdCreateTIFF.FileName, "w");
IntPtr pBuffer;
if (chkSaveStrips.Checked)
{
rowsPerStrip = Convert.ToInt16(tbSaveRowsPerStrip.Text);
}
// set required tag. WATCH THE TYPES!!!
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_IMAGEWIDTH, (short)width);
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_IMAGELENGTH, (short)height);
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_BITSPERSAMPLE, (int)16);
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_SAMPLESPERPIXEL, (short)1);
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_ROWSPERSTRIP, (short)rowsPerStrip);
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_PHOTOMETRIC, (short)TIFFTags.PHOTOMETRIC_MINISBLACK);
LibTIFF.SetField(newTiff, (int)TIFFTags.TIFFTAG_PLANARCONFIG, (short)TIFFTags.PLANARCONFIG_CONTIG);
if (chkSaveStrips.Checked)
{
// write strips
pBuffer = LibTIFF._malloc(width * 2 * rowsPerStrip);
// assume raw data to be provided as short[]
short[] shortbits = new short[width * rowsPerStrip];
// strips
int strips = height / rowsPerStrip;
for (int strip = 0; strip < strips; strip++)
{
for (int y = 0; y < rowsPerStrip; y++)
{
// pixels in line: set to specific gray value
for (int x = 0; x < width; x++)
{
// short = -32,768 to 32,767 = signed 16-bit integer
// ushort is not supported by Marshal.Copy
shortbits[y * width + x] = (short)(10 * y);
}
}
// copy data to unsafe context
Marshal.Copy(shortbits, 0, pBuffer, width * rowsPerStrip);
// ... and write to file
int ret = LibTIFF.WriteRawStrip(newTiff, (uint)strip, pBuffer, width * 2 * rowsPerStrip);
if (ret == -1)
{
Console.WriteLine("writing strip " + strip + " returned " + ret);
}
}
}
else
{
// write scanline by scanline
pBuffer = LibTIFF._malloc(width * 2); // 16 bpp
// assume raw data to be provided as short[]
short[] shortbits = new short[width];
// lines
for (int y = 0; y < height; y++)
{
// pixels in line: set to specific gray value
for (int x = 0; x < width; x++)
{
// short = -32,768 to 32,767 = signed 16-bit integer
// ushort is not supported by Marshal.Copy
shortbits[x] = (short)(100 * y);
}
// copy data to unsafe context
Marshal.Copy(shortbits, 0, pBuffer, width);
// ... and write to file
if (!LibTIFF.WriteScanline(newTiff, pBuffer, (uint)y))
{
Console.WriteLine("writing line " + y + " failed.");
}
}
}
LibTIFF._free(pBuffer);
LibTIFF.Close(newTiff);
MessageBox.Show("Time: " + (DateTime.Now - startTime));
}
/// <summary>Creates a Bitmap object from a libtiff handle.</summary>
/// <param name="tiff">Source image handle, 16 bit grayscale</param>
/// <param name="min">Min source histogram value => mapped to 0</param>
/// <param name="max">Max source histogram value => mapped to 255</param>
/// <returns>The Bitmap object. Remember to dispose the bitmap data
/// before abandoning the object!</returns>
private Bitmap GetBitmapFromTIFFHandle(IntPtr tiff, ushort min, ushort max)
{
UInt32 imageWidth, imageLength;
UInt16 bitsPerSample, samplesPerPixel;
int scanlineSize = LibTIFF.ScanlineSize(tiff);
Bitmap bmp;
// get image parameters
LibTIFF.GetField(tiff, (int)TIFFTags.TIFFTAG_IMAGEWIDTH, out imageWidth);
LibTIFF.GetField(tiff, (int)TIFFTags.TIFFTAG_IMAGELENGTH, out imageLength);
LibTIFF.GetField(tiff, (int)TIFFTags.TIFFTAG_BITSPERSAMPLE, out bitsPerSample);
LibTIFF.GetField(tiff, (int)TIFFTags.TIFFTAG_SAMPLESPERPIXEL, out samplesPerPixel);
if (bitsPerSample != 16 || samplesPerPixel != 1)
{
// this is not a 16bit grayscale TIFF file -- return
return(null);
}
// allocate memory for bitmap
IntPtr bmpData = LibTIFF._malloc((int)(scanlineSize / 2 * imageLength));
tbInitialScan0Ptr.Text = bmpData.ToString();
// read scanline by scanline
IntPtr pScanline = LibTIFF._malloc(scanlineSize);
for (UInt32 row = 0; row < imageLength; row++)
{
LibTIFF.ReadScanline(tiff, pScanline, row);
unsafe
{
ushort *srcBits16bit = (ushort *)pScanline; // source: 16bit grayscale bitmap
byte * dstBitsPalette = (byte *)bmpData; // dest.: 8bit palette bitmap
for (int i = 0; i < imageWidth; i++)
{
// scale each pixel's color according to given limits
if (srcBits16bit[i] <= min)
{
dstBitsPalette[i + row * imageWidth] = 0;
}
else if (srcBits16bit[i] >= max)
{
dstBitsPalette[i + row * imageWidth] = 255;
}
else
{
dstBitsPalette[i + row * imageWidth] =
(byte)(((long)srcBits16bit[i] - (long)min) * (long)255 / ((long)max - min));
}
}
}
}
LibTIFF._free(pScanline);
// create the Bitmap object using the read bitmap data
bmp = new Bitmap((int)imageWidth, (int)imageLength, scanlineSize / 2,
PixelFormat.Format8bppIndexed, bmpData);
// setup grayscale palette
ColorPalette palette = bmp.Palette;
for (int i = 0; i < 256; i++)
{
Color c = Color.FromArgb(i, i, i);
palette.Entries[i] = c;
}
bmp.Palette = palette;
return(bmp);
}