Transparency detection in palette PNGs

[Seishiin]

Is it possible to detect if a palette-based PNG has transparency without having to decode the whole image?

var imageInfo = Image.Identify("example.png");
var metadata = imageInfo.Metadata.GetPngMetadata();
var colorType = metadata.ColorType; // PngColorType.Palette
var transparency = metadata.HasTransparency; // false
var bpp = imageInfo.PixelType.BitsPerPixel; // 8

Am I missing something or is it just not possible?
example.zip

[JimBobSquarePants]

You're looking for Image.Identify

[Seishiin]

I already tried that, but the image I provided returns false for HasTransparency.

[JimBobSquarePants]

Ah right....

I think you may have found a bug. Looking at our decoder code we only assign true to the property if the color type is Rgb or GrayScale.

Can you please raise an issue?

[Seishiin]

Will do.
Thanks.