private void ApplyResizeSettings(ResizeSettings settings, GhostscriptSettings ghostscriptSettings)
{
// Parse resize settings
// - graphicsAlphaBits
int graphicsAlphaBits = settings.GetValueOrDefault("graphicsbits", 0);
if (!_validAlphaBitValues.Contains(graphicsAlphaBits))
{
// Use default value
graphicsAlphaBits = _validAlphaBitValues.Last();
}
ghostscriptSettings.Add(GhostscriptArgument.GraphicsAlphaBits, graphicsAlphaBits);
// - textAlphaBits
int textAlphaBits = settings.GetValueOrDefault("textbits", 0);
if (!_validAlphaBitValues.Contains(textAlphaBits))
{
// Use default value
textAlphaBits = _validAlphaBitValues.Last();
}
ghostscriptSettings.Add(GhostscriptArgument.TextAlphaBits, textAlphaBits);
ghostscriptSettings[GhostscriptArgument.GridFitTT] = (settings.Get <bool>("gridfit") == true ? 2 : 0).ToString(NumberFormatInfo.InvariantInfo);
ghostscriptSettings[GhostscriptArgument.AlignToPixels] = (settings.Get <bool>("subpixels") == true ? 1 : 0).ToString(NumberFormatInfo.InvariantInfo);
if (settings.Get <bool>("printed", true) == false)
{
ghostscriptSettings.Remove(GhostscriptArgument.Printed);
}
}
private void ApplyResizeSettings(ResizeSettings settings, GhostscriptSettings ghostscriptSettings)
{
// Parse resize settings
// - graphicsAlphaBits
int graphicsAlphaBits = settings.GetValueOrDefault("graphicsbits", 0);
if(!_validAlphaBitValues.Contains(graphicsAlphaBits))
{
// Use default value
graphicsAlphaBits = _validAlphaBitValues.Last();
}
ghostscriptSettings.Add(GhostscriptArgument.GraphicsAlphaBits, graphicsAlphaBits);
// - textAlphaBits
int textAlphaBits = settings.GetValueOrDefault("textbits", 0);
if(!_validAlphaBitValues.Contains(textAlphaBits))
{
// Use default value
textAlphaBits = _validAlphaBitValues.Last();
}
ghostscriptSettings.Add(GhostscriptArgument.TextAlphaBits, textAlphaBits);
ghostscriptSettings[GhostscriptArgument.GridFitTT] = (settings.Get<bool>("gridfit") == true ? 2 : 0).ToString(NumberFormatInfo.InvariantInfo);
ghostscriptSettings[GhostscriptArgument.AlignToPixels] = (settings.Get<bool>("subpixels") == true ? 1 : 0).ToString(NumberFormatInfo.InvariantInfo);
if (settings.Get<bool>("printed",true) == false) ghostscriptSettings.Remove(GhostscriptArgument.Printed);
}
public override Bitmap DecodeStream(Stream s, ResizeSettings settings, string optionalPath)
{
if(string.IsNullOrEmpty(optionalPath))
{
if (s.CanSeek) {
//Check the header instead if no filename is present.
byte[] header = new byte[4];
s.Read(header, 0, 4);
bool isPdf = (header[0] == '%' && header[1] == 'P' && header[2] == 'D' && header[3] == 'F');
s.Seek(-4, SeekOrigin.Current); //Restore position.
if (!isPdf) return null;
} else {
return null; //It's not seekable, we can't check the header.
}
} else if(!_supportedExtensions.Contains(Path.GetExtension(optionalPath), StringComparer.OrdinalIgnoreCase))
{
// Not a supported format
return null;
}
// Do not allow decoding if Ghostscript there are issues with performing this decode
IIssue[] issues = GetIssues().ToArray();
if(issues.Length > 0)
{
string message = string.Join(Environment.NewLine, issues.Select(x => x.Summary).ToArray());
throw new InvalidOperationException(message);
}
// Must write input stream to a temporary file for Ghostscript to process.
FileInfo tempInputPathInfo = new FileInfo(Path.GetTempFileName());
try
{
using(FileStream tempInputStream = tempInputPathInfo.Create())
{
StreamExtensions.CopyToStream(s, tempInputStream);
}
// Get information about the PDF such as page count and media boxes
// Although this creates a second trip to Ghostscript engine, it's not possible to generate a rendered image in exact
// dimensions requested. Skipping this step will cause a rendered image, of some size, to be resized further.
PdfInfo pdfInfo = GetPdfInfo(tempInputPathInfo.FullName);
// Extract the requested page number from resize settings, or default to first page
int pageNumber = settings.GetValueOrDefault("page", 1);
// Try to get the page number from PDF info. If not available, abort. This is caused by
// requesting a page that does not exist.
PageInfo pageInfo = pdfInfo.Pages.SingleOrDefault(x => x.Number == pageNumber);
if(pageInfo == null)
{
return null;
}
// We only support media box (as opposed to clip, bleed, art, etc.) If this is not available, abort.
if(pageInfo.MediaBox == null)
{
return null;
}
// Get the output size of the generated bitmap by applying the resize settings and media box.
Size outputSize = (pageInfo.Rotate == -90 || pageInfo.Rotate == 90) ?
GetOutputSize(settings, pageInfo.MediaBox.Height,pageInfo.MediaBox.Width)
: GetOutputSize(settings, pageInfo.MediaBox.Width, pageInfo.MediaBox.Height) ;
// Create default Ghostscript settings and apply the resize settings.
GhostscriptSettings ghostscriptSettings = new GhostscriptSettings
{
GhostscriptArgument.NoPause,
GhostscriptArgument.Quiet,
GhostscriptArgument.Safer,
GhostscriptArgument.Batch,
{GhostscriptArgument.OutputDevice, "pngalpha"},
{GhostscriptArgument.MaxBitmap, 24000000},
{GhostscriptArgument.RenderingThreads, 4},
{GhostscriptArgument.GridFitTT, 0},
{GhostscriptArgument.AlignToPixels, 0}, //Subpixel rendering depends on output device... perhaps testing would help determine if 1 would be better?
{GhostscriptArgument.FirstPage, pageNumber},
{GhostscriptArgument.LastPage, pageNumber},
GhostscriptArgument.Printed,
GhostscriptArgument.PdfFitPage,
GhostscriptArgument.FixedMedia,
{GhostscriptArgument.Height, outputSize.Height},
{GhostscriptArgument.Width, outputSize.Width}
};
ApplyResizeSettings(settings, ghostscriptSettings);
// Have Ghostscript process the input to a PNG file with transparency.
// The PNG will be reloaded and further processed by the resizer pipeline.
FileInfo tempOutputPathInfo = new FileInfo(Path.GetTempFileName());
try
{
// Add output file and input file. The input file must be the very last argument.
ghostscriptSettings.Add(GhostscriptArgument.OutputFile, tempOutputPathInfo.FullName);
ghostscriptSettings.Add(tempInputPathInfo.FullName);
_engine.Execute(ghostscriptSettings);
// NOTE: Do not dispose of memory stream because it is used as the backing source for the loaded bitmap.
MemoryStream memoryStream = new MemoryStream((int)tempOutputPathInfo.Length);
using(FileStream fileStream = tempOutputPathInfo.Open(FileMode.Open))
{
StreamExtensions.CopyToStream(fileStream, memoryStream);
}
// Per ImagerResizer plugin example source code:
// NOTE: If the Bitmap class is used for decoding, read gdi-bugs.txt and make sure you set b.Tag to new BitmapTag(optionalPath,stream);
BitmapTag bitmapTag = new BitmapTag("ghostscript.png", memoryStream);
return new Bitmap(memoryStream) { Tag = bitmapTag };
}
//catch(GhostscriptException)
//{
// // Conversion failed
// return null; //or maybe we should show details? If it's a valid PDF?
//}
finally
{
tempOutputPathInfo.Delete();
}
}
finally
{
tempInputPathInfo.Delete();
}
}
public override Bitmap DecodeStream(Stream s, ResizeSettings settings, string optionalPath)
{
if (string.IsNullOrEmpty(optionalPath))
{
if (s.CanSeek)
{
//Check the header instead if no filename is present.
byte[] header = new byte[4];
s.Read(header, 0, 4);
bool isPdf = (header[0] == '%' && header[1] == 'P' && header[2] == 'D' && header[3] == 'F');
s.Seek(-4, SeekOrigin.Current); //Restore position.
if (!isPdf)
{
return(null);
}
}
else
{
return(null); //It's not seekable, we can't check the header.
}
}
else if (!_supportedExtensions.Contains(Path.GetExtension(optionalPath), StringComparer.OrdinalIgnoreCase))
{
// Not a supported format
return(null);
}
// Do not allow decoding if Ghostscript there are issues with performing this decode
IIssue[] issues = GetIssues().ToArray();
if (issues.Length > 0)
{
string message = string.Join(Environment.NewLine, issues.Select(x => x.Summary).ToArray());
throw new InvalidOperationException(message);
}
// Must write input stream to a temporary file for Ghostscript to process.
FileInfo tempInputPathInfo = new FileInfo(Path.GetTempFileName());
try
{
using (FileStream tempInputStream = tempInputPathInfo.Create())
{
StreamExtensions.CopyToStream(s, tempInputStream);
}
// Get information about the PDF such as page count and media boxes
// Although this creates a second trip to Ghostscript engine, it's not possible to generate a rendered image in exact
// dimensions requested. Skipping this step will cause a rendered image, of some size, to be resized further.
PdfInfo pdfInfo = GetPdfInfo(tempInputPathInfo.FullName);
// Extract the requested page number from resize settings, or default to first page
int pageNumber = settings.GetValueOrDefault("page", 1);
// Try to get the page number from PDF info. If not available, abort. This is caused by
// requesting a page that does not exist.
PageInfo pageInfo = pdfInfo.Pages.SingleOrDefault(x => x.Number == pageNumber);
if (pageInfo == null)
{
return(null);
}
// We only support media box (as opposed to clip, bleed, art, etc.) If this is not available, abort.
if (pageInfo.MediaBox == null)
{
return(null);
}
// Get the output size of the generated bitmap by applying the resize settings and media box.
Size outputSize = (pageInfo.Rotate == -90 || pageInfo.Rotate == 90) ?
GetOutputSize(settings, pageInfo.MediaBox.Height, pageInfo.MediaBox.Width)
: GetOutputSize(settings, pageInfo.MediaBox.Width, pageInfo.MediaBox.Height);
// Create default Ghostscript settings and apply the resize settings.
GhostscriptSettings ghostscriptSettings = new GhostscriptSettings
{
GhostscriptArgument.NoPause,
GhostscriptArgument.Quiet,
GhostscriptArgument.Safer,
GhostscriptArgument.Batch,
{ GhostscriptArgument.OutputDevice, "pngalpha" },
{ GhostscriptArgument.MaxBitmap, 24000000 },
{ GhostscriptArgument.RenderingThreads, 4 },
{ GhostscriptArgument.GridFitTT, 0 },
{ GhostscriptArgument.AlignToPixels, 0 }, //Subpixel rendering depends on output device... perhaps testing would help determine if 1 would be better?
{ GhostscriptArgument.FirstPage, pageNumber },
{ GhostscriptArgument.LastPage, pageNumber },
GhostscriptArgument.Printed,
GhostscriptArgument.PdfFitPage,
GhostscriptArgument.FixedMedia,
{ GhostscriptArgument.Height, outputSize.Height },
{ GhostscriptArgument.Width, outputSize.Width }
};
ApplyResizeSettings(settings, ghostscriptSettings);
// Have Ghostscript process the input to a PNG file with transparency.
// The PNG will be reloaded and further processed by the resizer pipeline.
FileInfo tempOutputPathInfo = new FileInfo(Path.GetTempFileName());
try
{
// Add output file and input file. The input file must be the very last argument.
ghostscriptSettings.Add(GhostscriptArgument.OutputFile, tempOutputPathInfo.FullName);
ghostscriptSettings.Add(tempInputPathInfo.FullName);
_engine.Execute(ghostscriptSettings);
// NOTE: Do not dispose of memory stream because it is used as the backing source for the loaded bitmap.
MemoryStream memoryStream = new MemoryStream((int)tempOutputPathInfo.Length);
using (FileStream fileStream = tempOutputPathInfo.Open(FileMode.Open))
{
StreamExtensions.CopyToStream(fileStream, memoryStream);
}
// Per ImagerResizer plugin example source code:
// NOTE: If the Bitmap class is used for decoding, read gdi-bugs.txt and make sure you set b.Tag to new BitmapTag(optionalPath,stream);
BitmapTag bitmapTag = new BitmapTag("ghostscript.png", memoryStream);
return(new Bitmap(memoryStream)
{
Tag = bitmapTag
});
}
//catch(GhostscriptException)
//{
// // Conversion failed
// return null; //or maybe we should show details? If it's a valid PDF?
//}
finally
{
tempOutputPathInfo.Delete();
}
}
finally
{
tempInputPathInfo.Delete();
}
}
