I'm working on page speed and Google PageSpeed Insights is telling me that my PNGs are just way too large. Sadly .NET does not provide any way to optimize PNG images so there is no easy fix - just unmanaged libraries and command line tools.
I have an allergy to manual processes so I've lashed up some code to automatically find and optimize PNGs in my App_Data folder using PNGCRUSH . I can call CrushAllImages() to fix up everything or CrushImage() when I need to fix up a specific PNG. Code below:
public static void CrushAllImages()
{
try
{
string appDataRoot = HostingEnvironment.MapPath("~/App_Data");
if (appDataRoot == null)
{
return;
}
DirectoryInfo directoryInfo = new DirectoryInfo(appDataRoot);
FileInfo[] pngs = directoryInfo.GetFiles("*.png", SearchOption.AllDirectories);
foreach (FileInfo png in pngs)
{
CrushImage(png.FullName);
}
}
catch (Exception ex)
{
//...
}
}
public static void CrushImage(string fullPath)
{
if (string.IsNullOrEmpty(fullPath))
{
return;
}
try
{
string markerPath = Path.ChangeExtension(fullPath, ".cng");
if (File.Exists(markerPath))
{
return;
}
string crushExe = HostingEnvironment.MapPath("~/App_Data/pngcrush_1_7_77_w32.exe");
ProcessStartInfo psi = new ProcessStartInfo(crushExe, string.Format(CultureInfo.InvariantCulture, "\"{0}\" \"{1}\"", fullPath, markerPath));
psi.UseShellExecute = false;
psi.CreateNoWindow = true;
psi.LoadUserProfile = false;
psi.WorkingDirectory = HostingEnvironment.MapPath("~/App_Data");
Process p = Process.Start(psi);
if (p == null)
{
throw new InvalidOperationException("No Process!");
}
p.WaitForExit();
if (File.Exists(markerPath))
{
if (p.ExitCode == 0)
{
File.Copy(markerPath, fullPath, true);
File.WriteAllText(markerPath, "Processed");
}
else
{
SiteLog.Log.Add(LogSeverity.Error, "CrushImage Failed (non-0 exit code) for " + fullPath);
File.Delete(markerPath);
}
}
}
catch (Exception ex)
{
// ...
}
}
(Related: Long term solar powered time lapse camera using Arduino ; Capture DropCam (Nest Cam) frames to Google Drive ; Style Transfer for Time Lapse Photography )
(You might also like: Launching a URL in the user's default browser ; International Date Line Longitude, Latitude Coordinates ; What can I do for Brown? )
(All Code Posts )