private static void StartCompression(MagickImage image, bool lossless)
{
ImageOptimizerHelper.CheckFormat(image, MagickFormat.Png);
if (!lossless)
{
image.Strip();
image.Settings.SetDefine(MagickFormat.Png, "exclude-chunks", "all");
image.Settings.SetDefine(MagickFormat.Png, "include-chunks", "tRNS,gAMA");
}
}
private bool DoLosslessCompress(FileInfo file)
{
bool isCompressed = false;
using (MagickImage image = new MagickImage(file))
{
ImageOptimizerHelper.CheckFormat(image, MagickFormat.Png);
image.Strip();
image.Settings.SetDefine(MagickFormat.Png, "exclude-chunks", "all");
image.Settings.SetDefine(MagickFormat.Png, "include-chunks", "tRNS,gAMA");
CheckTransparency(image);
Collection <TemporaryFile> tempFiles = new Collection <TemporaryFile>();
try
{
TemporaryFile bestFile = null;
foreach (int quality in GetQualityList())
{
TemporaryFile tempFile = new TemporaryFile();
tempFiles.Add(tempFile);
image.Quality = quality;
image.Write(tempFile);
if (bestFile == null || bestFile.Length > tempFile.Length)
{
bestFile = tempFile;
}
}
if (bestFile.Length < file.Length)
{
isCompressed = true;
bestFile.CopyTo(file);
file.Refresh();
}
}
finally
{
foreach (TemporaryFile tempFile in tempFiles)
{
tempFile.Dispose();
}
}
}
return(isCompressed);
}
private static bool DoLosslessCompress(FileInfo file, IMagickImage <QuantumType> image)
{
ImageOptimizerHelper.CheckFormat(image, MagickFormat.Gif);
bool isCompressed = false;
using (TemporaryFile tempFile = new TemporaryFile())
{
LosslessCompress(image);
image.Write(tempFile);
if (tempFile.Length < file.Length)
{
isCompressed = true;
tempFile.CopyTo(file);
file.Refresh();
}
}
return(isCompressed);
}
private static bool DoLosslessCompress(Stream stream, long startPosition, IMagickImage image)
{
ImageOptimizerHelper.CheckFormat(image, MagickFormat.Gif);
bool isCompressed = false;
using (MemoryStream memStream = new MemoryStream())
{
LosslessCompress(image);
image.Write(memStream);
if (memStream.Length < (stream.Length - startPosition))
{
isCompressed = true;
memStream.CopyTo(stream);
stream.SetLength(startPosition + memStream.Length);
}
}
return(isCompressed);
}