Good work!
Edit: As mentioned on : https://www.hanselman.com/blog/RFCServersideImageAndGraphics...
Currently, as of the time of this blog post's writing, .NET Core has no good built-in option for image resizing or image generation/creation. There is no System.Drawing because there is no Win32 GDI. There are some options, that I'll point out later, but this clearly hasn't been a priority so it's not done yet. There has been some work on System.Drawing.Graphics, but it seems stalled.
Nathanael Jones is the very accomplished author of ImageResizer and the primary at Imazen, an imaging software company. I've talked about ImageResizer before, it's fantastic. Nathanael has been pushing hard to get folks at Microsoft to commit to a story around Server-side Graphics in ASP.NET 5 and recently updated his own roadmap with respect to ImageResizer and the new ASP.NET 5 (that runs on .NET Core as well as the full .NET Framework). Take a moment and read it, there's a lot there. Concerns about how to call native code, how to distribute managed code that has to call native code, and lots more. I've worked with Nathanael for the last year trying to work out some way to solve this problem but it hasn't worked out well. Big company, sigh.
Edit 2: Even a successfull kickstarter about this: https://www.kickstarter.com/projects/njones/imageflow-respec...
I know Nathanael and have chatted plenty with him over the years on the subject. We're trying to solve different problems really in the field and I really hope he achieves what he wants.
We've got pretty good performance so far ( faster than System.Drawing in many regards and we know how to improve it further) and a great feature set but we still have a lot to do.
https://github.com/JimBobSquarePants/ImageSharp/blob/master/...
I'm personally working with another chap on ICC profile support just now which is very complicated but will give us a full color management system once finished.
While I figure that out I'm hoping that some of the performance gurus out there will step up and offer to tweak the library where necessary.
Or perhaps try pinching the. Net core team?
I don't know if there are done simple things I can help, but my knowledge about this is limited