Quantization example code

[simonmurrell1979]

Hello

I hope you are doing well. Is there any example code on loading a PNG image and applying ImageSharp quantization to a PNG file?

I have been using PngQuant to compress images but am looking for a better solution and came across this library. Saw example images below.

https://jimbobsquarepants.github.io/wudemo/

[JimBobSquarePants]

Sure...

string inPath = "...";
string outPath = "...";
using Image image = Image.Load(inPath);
image.Save(outPath, new PngEncoder() { ColorType = PngColorType.Palette, BitDepth = PngBitDepth.Bit8 });

There are overloads for Load/Save that take streams also.

[simonmurrell1979]

I am trying to make the image smaller like your WuDemo. Not sure if I am doing it correctly or not?

using (SixLabors.ImageSharp.Image image = SixLabors.ImageSharp.Image.Load(@"C:\Users\SimonM\Desktop\Temp\input.png"))
{

            var quantizer = new WuQuantizer(new QuantizerOptions 
            { 
                Dither = null, 
                MaxColors = 256 
            });

            image.Mutate(x => x.Quantize(quantizer));

            image.Save(@"C:\Users\SimonM\Desktop\Temp\output.png",
                new PngEncoder() { ColorType = PngColorType.Palette, BitDepth = PngBitDepth.Bit8 });
            image.Save(@"C:\Users\SimonM\Desktop\Temp\output2.png");

        }

[JimBobSquarePants]

My sample encodes the image as an 8 bit palette png that is quantized using the Wu Quantizer by default.

There’s no need to explicitly quantize and you can pass your own quantizer to the encoder

[simonmurrell1979]

Ah okay. I see. Thank you for the information. I want confused as the file was ending up being larger than the input. It also helps if you given the correct input file to test with ;)