.NET Core has neither WinForms nor WPF. It's very much focused on web applications. System.Drawing might be useful for ... one in ten? web applications. And they have released it, and it's getting plenty of traction.
To re-use System.Drawing Microsoft would need to re-implement all those methods in a cross-platform, bug-compatible way. And there's a lot of code behind those methods.
In my opinion they made a reasonable decision to leave it out of v1.
No, my understanding of .Net core is that this is also the way they want to get back on devices. I think Xamarin will ultimately be based on .net Core. And for a mobile app, you bet you need a way to manipulate images.
Even for websites, depends on what sort of websites you do, but I often need to display charts, so being able to generate images on the fly.
Why are you generating images on the fly to display a chart? Why not send the data points and render a chart clientside using JavaScript? There are plenty of libraries for that.
A lot of clients want native PDF output for their reports. None of the PDF generating libraries I know of support running JS. So if you want the same charts in both, you need to generate the images server side.
I am sure there are other ways but I found using the native datavisualization library very useful and simple to use. I am one of these guys who do as little javascript as necessary.
If you want to draw the chart from scratch perhaps but I use a library to generate the chart then send it as an image to the client. Very few lines of code required in .net, no javascript required.
Indeed, but there's still a heavy focus on web applications.
I have written a few commercial cross-platform applications with Xamarin. They deal with images - and System.Drawing would not have been helpful to me. iOS has UIImage and Android has Bitmap.
I have not worked with a website yet that didn't have a need for image-handling code, either to resize uploaded images, handle avatar generation, draw charts (although I suppose that's moving to client-side for newer apps), etc.
Frankly, the thing I liked best about the whole .net ecosystem is that it didn't go for the open source "release early, release often, release incomplete and buggy" philosophy. I'm just very disappointed to see Microsoft going in this direction.
If Microsoft isn't providing a rock-solid, feature-ful framework with impeccable backwards compatibility, who will? Nobody will.
A lot of stuff in System.Drawing is pure algorithm and should be easy to port to other platforms. It will be tricky once you do screen output but the image processing routines shouldn't be too hard to port and they are super useful for a lot of web apps that do reporting and other things.
Take a quick scroll through here: http://referencesource.microsoft.com/#System.Drawing/commonu...
To re-use System.Drawing Microsoft would need to re-implement all those methods in a cross-platform, bug-compatible way. And there's a lot of code behind those methods.
In my opinion they made a reasonable decision to leave it out of v1.