diff --git a/src/ImageSharp/Formats/Tga/TgaDecoderCore.cs b/src/ImageSharp/Formats/Tga/TgaDecoderCore.cs index 26e057bff9..eb0e508cd9 100644 --- a/src/ImageSharp/Formats/Tga/TgaDecoderCore.cs +++ b/src/ImageSharp/Formats/Tga/TgaDecoderCore.cs @@ -937,7 +937,9 @@ internal sealed class TgaDecoderCore : IImageDecoderInternals this.tgaMetadata = this.metadata.GetTgaMetadata(); this.tgaMetadata.BitsPerPixel = (TgaBitsPerPixel)this.fileHeader.PixelDepth; - int alphaBits = this.fileHeader.ImageDescriptor & 0xf; + // TrueColor images with 32 bits per pixel are assumed to always have 8 bit alpha channel, + // because some encoders do not set correctly the alpha bits in the image descriptor. + int alphaBits = this.IsTrueColor32BitPerPixel(this.tgaMetadata.BitsPerPixel) ? 8 : this.fileHeader.ImageDescriptor & 0xf; if (alphaBits is not 0 and not 1 and not 8) { TgaThrowHelper.ThrowInvalidImageContentException("Invalid alpha channel bits"); @@ -949,4 +951,8 @@ internal sealed class TgaDecoderCore : IImageDecoderInternals // Bits 4 and 5 describe the image origin. return (TgaImageOrigin)((this.fileHeader.ImageDescriptor & 0x30) >> 4); } + + private bool IsTrueColor32BitPerPixel(TgaBitsPerPixel bitsPerPixel) => bitsPerPixel == TgaBitsPerPixel.Pixel32 && + (this.fileHeader.ImageType == TgaImageType.TrueColor || + this.fileHeader.ImageType == TgaImageType.RleTrueColor); } diff --git a/src/ImageSharp/Formats/Tga/TgaFileHeader.cs b/src/ImageSharp/Formats/Tga/TgaFileHeader.cs index 007dc03de1..2613cd610a 100644 --- a/src/ImageSharp/Formats/Tga/TgaFileHeader.cs +++ b/src/ImageSharp/Formats/Tga/TgaFileHeader.cs @@ -131,10 +131,7 @@ internal readonly struct TgaFileHeader /// public byte ImageDescriptor { get; } - public static TgaFileHeader Parse(Span data) - { - return MemoryMarshal.Cast(data)[0]; - } + public static TgaFileHeader Parse(Span data) => MemoryMarshal.Cast(data)[0]; public void WriteTo(Span buffer) {