private static void ReadPngFile(CommandLineOptions opts, ParseContext context, IcoFrame frame, byte[] sourceFile, out bool canSourceBePreserved)
{
using (var stream = new MemoryStream(sourceFile))
{
var decoder = new SixLabors.ImageSharp.Formats.Png.PngDecoder();
frame.CookedData = decoder.Decode <Rgba32>(new Configuration(), stream);
}
var encoding = PngDecoder.GetPngFileEncoding(new Memory <byte>(sourceFile));
frame.Encoding.Type = IcoEncodingType.Png;
frame.Encoding.ClaimedBitDepth = 32;
frame.Encoding.ActualBitDepth = 32;
canSourceBePreserved = encoding.ColorType == PngColorType.RGBA && encoding.BitsPerChannel == 8;
}
public static void DoPngEntry(ByteReader bitmapHeader, ParseContext context, IcoFrame source)
{
if (source.Encoding.ClaimedBitDepth != 32)
{
context.Reporter.WarnLine(IcoErrorCode.PngNot32Bit, $"PNG-encoded image with bit depth {source.Encoding.ClaimedBitDepth} (expected 32).", context.DisplayedPath, context.ImageDirectoryIndex.Value);
}
using (var stream = new MemoryStream(bitmapHeader.Data.ToArray()))
{
var decoder = new SixLabors.ImageSharp.Formats.Png.PngDecoder();
source.CookedData = decoder.Decode <Rgba32>(new Configuration(), stream);
}
source.Encoding.Type = IcoEncodingType.Png;
source.Encoding.PixelFormat = BmpUtil.IsAnyPartialTransparency(source.CookedData) ? BitmapEncoding.Pixel_argb32 : BitmapEncoding.Pixel_0rgb32;
source.Mask = GenerateMaskFromAlpha(source.CookedData);
// Conservatively assume that the output wouldn't have used palette trimming, if it had been a bmp frame.
if (source.Encoding.ClaimedBitDepth < 16)
{
source.Encoding.PaletteSize = 1u << (int)source.Encoding.ClaimedBitDepth;
}
var encoding = GetPngFileEncoding(bitmapHeader.Data);
if (encoding.ColorType != PngColorType.RGBA)
{
context.Reporter.WarnLine(IcoErrorCode.PngNotRGBA32, $"ICO files require the embedded PNG image to be encoded in RGBA32 format; this is {encoding.ColorType}", context.DisplayedPath, context.ImageDirectoryIndex.Value);
}
else if (encoding.BitsPerChannel != 8)
{
context.Reporter.WarnLine(IcoErrorCode.PngNotRGBA32, $"ICO files require the embedded PNG image to be encoded in RGBA32 format; this is RGBA{encoding.BitsPerChannel * 4}", context.DisplayedPath, context.ImageDirectoryIndex.Value);
}
uint numChannels = 0;
switch (encoding.ColorType)
{
case PngColorType.Grayscale:
numChannels = 1;
break;
case PngColorType.RGB:
numChannels = 3;
break;
case PngColorType.GrayscaleAlpha:
numChannels = 2;
break;
case PngColorType.RGBA:
numChannels = 4;
break;
case PngColorType.Palette:
default:
break;
}
source.Encoding.ActualHeight = encoding.Height;
source.Encoding.ActualWidth = encoding.Width;
source.Encoding.ActualBitDepth = encoding.BitsPerChannel * numChannels;
}