How to create hash from a bitmap... about imagehash

[LambertWM]

Not sure what you mean, the interface uses an image that is "in memory", so it is completely up to you to decide where the image originates from.

namespace CoenM.ImageHash
{
    public interface IImageHash
    {
        ulong Hash(Image<Rgba32> image);
    }
}

[developervariety]

I believe they want to create a hash out of a Bitmap so they can save it in a database perhaps. This removes the need to save all images that you already know are "good", just need to find similar ones.

I am in need of this too, but I will keep looking.

[developervariety]

It just slapped me in the face, you save the ulong from the "good" images in a database for later use.

@leonpotgieter I hope this solves your issue.

[coenm]

You can take a look at this test code from ImageSharp where a Bitmap is converted to an Image<Rgba32> inmemory.

After obtaining such Image<Rgb32> you can call the Hash(Image<Rgb32> image) method as @LambertWM described.

You can also try to save the Bitmap to a MemoryStream and use the following extension method.

        public static ulong Hash(this IImageHash hashImplementation, Stream stream)
        {
            if (hashImplementation == null)
                throw new ArgumentNullException(nameof(hashImplementation));
            if (stream == null)
                throw new ArgumentNullException(nameof(stream));

            using (var image = Image.Load<Rgba32>(stream))
                return hashImplementation.Hash(image);
        }