P: Increase the strength of the blur tool.

@eric_tadsen_7968940 

Krita has this kind of brush. See my comment below.

Krita has this kind of brush.

Krita's brushes can have filters from Krita applied to them. They can use the filters as brushes.

There is a brush preset called Filter_Blur that blurs the pixels as a brush.

Its default blur value it's too weak for very big images with a high pixel density, but you can easily edit/customize the brush. You click on the brush icon at the top of the program, bellow the Settings, Window, Help buttons and select the Filter tab, then change the Horizontal and Vertical Radius (radii/radiuses) to make the blur stronger.

You can save this custom brush preset. Then you can use the Opacity slider to have a stronger or weaker effect while painting.

This blur tool can be a little slow on 2014 cpu (without AVX2) if your stroke is long and you are using a bigger image, e.g. 1474px X 2208 px at 300 ppi. The cpu is not maxed out when using the brush.

The performance is decent for a strong blur effect and moderate brush stroke speed. The advantage over other programs is that you don't have to use a new layer for the image that is blurred at a constant blur value, therefore you don't have to duplicate the image, blur it and mask the regions where you don't want the blur to show up on the original image below.

So Krita allows for a lot of different blur values inside a single brush without using layers.

Krita's blur tool workflow was better than the that of the "TR's Dodge and Burn (Blur and Sharpen)" Plugin for Paint.Net which is slower and not as .

*chris_cox_2148894 

How do I do that? I am very new, and don't know how to do that. 😞

Well, it's 2020 now and still no strong Blur tool. I understand the arguments that "It's not meant for that", "There are different ways of doing that",  etc. but being able to set the strength of the Blur tool to "stronger" than the very mild blurring it does at 100% still doesn't seem like asking for an awful lot.

For an example of how easy it really is, download and install Paint.NET, install the TR's Dodge and Burn (and blur) plugin and there you have it. A blur tool that when set to 80-90% will REALLY blur with a brush. "Why not use it then, and leave Photoshop alone," you ask? Because my workflow is in Photoshop, not in Paint.NET, that's why.

I do understand that it’s not intended for effect building, but I still agree that it’s too weak. Imagine this: You are creating a mask for a person in a portrait picture. The face is usually in focus, therefore your mask don’t need a lot of feather in that area. But other parts of the person are not in focus, hence the mask needs to be blurred in those parts. But most of the times the blur can’t be uniform, due to nature of the blur in a real world photograph. Making different selections and blurring the mask with the gaussian blur filter is not really intuitive – interactively creating that blur/feather with the blur tool is way more intuitive. But with the pixel dimensions of todays photographs the tool is simply too weak for that task. In short: The blur tool is a really great mask editing tool. But in a lot of cases it's unfortunately too weak for that task.

I googled "why is the blur tool so weak" and got to this page so obviously I totally agree with you. Using layers and masks is sometimes more effort then I want to go to to get a blur. The effect with the tool is WAY too subtle even at 100%. I can click on an area 50 times and barely tell that anything has happened. Why not simply make 100% much stronger and let people dial it back as they wish? You could argue that you should use layers and masks for any tool - burning, curves and etc., but shouldn't that discretion be left up to the user?

I would like to see the problem that you are trying to solve with Blur.  Is the anomaly separated from the background?  Peter Bailey's example with the background included will always fail if you expect to cover the background with blurred data.  Does someone file I can see and a few works explaining the anomaly not that Blur fails.  What would you do with real painting?

RONC

Smart filters are none destructive. Smoothing filters don't have unique inverses so can't be backed out like a simple scaling.
RONC

I glean from reading this thread that Adobe does not deem this a problem. I would say that their software is doing what is mathematically correct but you don't need math here. From a quick test I made, blur works correctly for what it is designed to do. Problem is that you want what I will call un-normalized blur. Un-normalized does not divide the result by the number of filter coefficients. I'm trying to think of a way to get the same effect without changing software.
I will have image showing un vs normalized in morning.

Tell me how you would do this with actual paint, canvas and brush. Do not add more paint when you blur it. The blur expands and gets weaker. Now if you un-normalize by adding paint you get what you want to do.

This is a communications problem more than anything.

RONC

Yeah, I would agree. I like you're idea better, not a toggle, but a strength slider.