Transparent Color not working for DrawText

[fritz-net]

Hey, I tried the Watermark example which works quite fine, however if I use a color with transparency I do not see any of that.
Am I'm doing something wrong?

I also tried color = color.WithAlpha(0.5f); which does give the same result

using (var img = Image.Load("fb.jpg"))
            {
                // For production application we would recommend you create a FontCollection
                // singleton and manually install the ttf fonts yourself as using SystemFonts
                // can be expensive and you risk font existing or not existing on a deployment
                // by deployment basis.
                Font font = SystemFonts.CreateFont("Arial", 10); // for scaling water mark size is largely ignored.

                var color = Color.HotPink;
                color = new Color(new Rgba32(200, 200, 200, 50));
                using (var img2 = img.Clone(ctx => ctx.ApplyScalingWaterMark(font, "A short piece of text", color, 5, false)))
                {
                    img2.Save("output/simple.png");
                }


                using (var img2 = img.Clone(ctx => ctx.ApplyScalingWaterMark(font, LongText, color, 5, true)))
                {
                    img2.Save("output/wrapped.png");
                }

                // The original `img` object has not been altered at all.
            }

[JimBobSquarePants]

Your jpeg is 24bit RGB. Using the non-generic variant Image will load that image as Rgb24. For alpha support you need to specify Rgba32 using the non-generic Image<TPixel>

[fritz-net]

I thought that the alpha channel of the image is irrelevant since the color is applied anyway and there is no alpha channel on the image itself/the result is alpha 100% anyway.

Thanks for your response, I fixed it using using (var img = Image.Load<Rgba32>("fb.jpg")). Using Image does not work (and seems to be the default anyway)

[JimBobSquarePants]

There is no default.

Jpegs contain no alpha channel so the non-generic Image for that format will represent either Rgb24 or L8 depending on the encoded color type. Other image formats will return Rgba32, Rgba64, L16 La16 or others depending on the encoded color type supported by that encoded format. These are deliberate decisions made by our decoders in order to be as efficiant as possible.

Using the generic image Image<T> tells the decoder to use your format instead. When drawing with a color that contains an alpha channel you need to ensure that the surface you are drawing upon supports that channel.