/// <summary>
/// Generates thumbnail using vips of the source image, always downscales (no upscale), saves the generated
/// file to thumbnails folder and returns new ThumbImage Model
/// </summary>
/// <param name="src">SourceImage</param>
/// <param name="width">Width of the image</param>
/// <param name="height">Optional Height of the image</param>
/// <returns>Empty ThumbImage if no file exists or Created ThumbImage</returns>
internal static ThumbImage CreateImage(SourceImage src, int width, int?height = null, int q = 100, Format format = Format.JPEG, bool strip = false)
{
// Checks, if the source file exists
if (src == null && File.Exists(src.AbsolutePath))
{
return(new ThumbImage());
}
// No uknown formats shall pass!
if (src.Format == Format.Unknown || format == Format.Unknown)
{
return(new ThumbImage());
}
// Load Image to Vips
Image image = Image.Thumbnail(src.AbsolutePath, width, height, "down", true);
//image = image.Copy();
int h = image.Height;
int w = image.Width;
// Create FileName and Path
String fileName = CreateThumbFilename(src, w, h, q, format.ToString().ToLower());
String filePath = FileService.CombineDirectoryAndFilename(GetThumbnailPath(), fileName);
switch (format)
{
case Format.JPEG:
image.Jpegsave(filePath, null, q, null, true, true, false, true, null, true, null, strip, new[] { 255.0, 255.0, 255.0 });
break;
case Format.GIF:
using (MagickImage imImage = new MagickImage(src.AbsolutePath))
{
imImage.Resize(w, h);
imImage.Quality = q;
if (strip)
{
imImage.Strip();
}
imImage.Write(filePath);
}
break;
case Format.PNG:
// Compression ratio is inverse of quality between 0 - 9
int pngQ = (q / 10 - 10) * -1;
image.Pngsave(filePath, pngQ, false, strip: strip);
break;
case Format.WebP:
if (q == 100)
{
image.Webpsave(filePath, null, q, true, nearLossless: true, strip: strip);
}
else
{
image.Webpsave(filePath, null, q, false, smartSubsample: true, strip: strip);
}
break;
case Format.TIFF:
image.Tiffsave(filePath, strip: strip);
break;
case Format.SVG:
return(src.GetOptimizedSVG());
}
// Create new ThumbImage Model
var thumb = new ThumbImage
{
AbsolutePath = filePath,
AltText = src.AltText,
FileName = fileName,
RelativePath = $"/thumbnails/{fileName}",
Height = h,
Width = w,
SourceID = src.ID,
Format = format,
FileSize = new FileInfo(filePath).Length,
Quality = q,
Stripped = strip
};
return(thumb);
}
