New Post: Strange Artifacts in Caption CMYK Image

Hi, I'm getting strange artifacts inside caption on CMYK image, check this screenshot:
.

Heres the code:

Imports ImageMagick

public class PageClass

    Inherits System.Web.UI.Page

    sub Page_Load(Src as Object, E As EventArgs)

        Response.ContentType = "image/JPEG"

        Dim backgroundImage As New MagickImage("https://www.dropbox.com/s/ftnjf3ov3gjth9x/test_cmyk.jpg?dl=1")

        'Uncomment this line for RGB test
        'Dim backgroundImage As New MagickImage("https://www.dropbox.com/s/jghdwo6e851m9tw/test_rgb.jpg?dl=1")

        backgroundImage.Quality = 100

        Dim settings As New MagickReadSettings()

        settings.Width = 300
        settings.Height = 200
        settings.FontPointSize = 80
        settings.BackgroundColor = MagickColors.Transparent
        settings.FillColor = new MagickColor(new ColorCMYK(new Percentage(6),new Percentage(7),new Percentage(96),new Percentage(0)))

        'Uncomment this line for RGB test
        'settings.FillColor = new MagickColor("#f2e22b")

        Dim textImage As New MagickImage("caption:test", settings)

        backgroundImage.Composite(textImage, 20, 20, CompositeOperator.Over)

        backgroundImage.Write(Response.OutputStream, MagickFormat.Jpeg)


    end sub


end class

In my tests I discovered that if increase the width considerably the artifacts do not appear.

If you prefer you can download all files here:
https://www.dropbox.com/sh/qya694v3guv8hk9/AADYFfCqm6udcfCQPByexSOQa?dl=0

Is something I'm doing wrong?

Thanks for this library, you're a lifesaver.