ImageProcessor | fluent wrapper around System.Drawing for the processing | Computer Vision library

Try adding the following dependency:

The issue is that your paths, while they work for Windows, will not work for Unix based systems as they use forward slashes - / - not backward slashes \ as a directory separator character.

Use Path.Combine for a cross-platform solution.

It will use the Path.DirectorySeparatorChar which will provide a platform-specific character:

I was able to solve my problem by using a different plugin package: Microscope Measurement Tools (https://imagej.net/plugins/microscope-measurement-tools). Very easy to customize to objective-specific calibrations. Note this plugin is for FIJI.

It looks like it was the result of using Configuration.Bind() in ConfigureServices(). It is working as expected after the following change there:

This is one of the most common problems we get asked, and it's also the one we are least equipped to answer, but you are most equipped to answer yourself.

Let me just explain what the error means: You have tried to use a variable, property, or a method return value but it contains null - which means that there is no instance of a class in the variable. It's a bit like a pocket: you have a pocket in your shirt, which you use to hold a pen. If you reach into the pocket and find there isn't a pen there, you can't sign your name on a piece of paper - and you will get very funny looks if you try! The empty pocket is giving you a null value (no pen here!) so you can't do anything that you would normally do once you retrieved your pen. Why is it empty? That's the question - it may be that you forgot to pick up your pen when you left the house this morning, or possibly you left the pen in the pocket of yesterday's shirt when you took it off last night.

We can't tell, because we weren't there, and even more importantly, we can't even see your shirt, much less what is in the pocket!

Back to computers, and you have done the same thing, somehow - and we can't see your code, much less run it and find out what contains null when it shouldn't. But you can - and your IDE will help you here. Run your program in the debugger and when it fails, the IDE will show you the line it found the problem on. You can then start looking at the various parts of it to see what value is null and start looking back through your code to find out why. So put a breakpoint at the beginning of the method containing the error line, and run your program from the start again. This time, it will stop before the error, and let you examine what is going on by stepping through the code looking at your values.

But we can't do that - we don't have your code, we don't know how to use it if we did have it, we don't have your data. So try it - and see how much information you can find out!

Your approach of overwriting POST parameters is more of a hack, because conceptually it means you are ignoring the data that suppose to come in from the user. So this is something I would recommend against in general:

The System.Drawing ColorMatrix class does not provide methods to multiply matrices to combine values which is how filters would normally be combined.

https://docs.microsoft.com/en-us/dotnet/api/system.drawing.imaging.colormatrix?view=netframework-4.8

Because of this I never designed the filter rules to allow for multiple combined requests.

However, there is nothing to stop you implementing and registering your own IWebGraphicsProcessor that allowed combining the commands into a single command.

The difference is due to the underlying camera implementation. The analyzer interface is from CameraX while the processor needs to be written by developer for camera1.

If you want to use android.hardware.Camera, you need to follow the example to create a processor and feed camera output to MLKit. If you want to use cameraX, then you can follow the example in the vision sample app and find CameraXLivePreviewActivity.

Firstly, it's not safe to use QPixmap outside the main thread. So you should use QImage instead.

Secondly, ImageQt shares the buffer from the Image passed to it. So if the buffer is deleted while the Qt image is still alive, a crash will very likely ensue. You might need to copy the Qt image to prevent this happening if you can't keep hold of the PIL image for long enough.