Negative Prompt Weight
This is a simple extension for the Stable Diffusion Web UI, which allows users to adjust the overall weight of the negative prompt, allowing you to increase or decrease its effect in a new way. Oh, and it writes the value to PNGinfo, honors it during 'send to txt2img' etc., and supports XYZ Plot.
What Does It Do?
Here's a demonstration of how it can continously reduce the effect of the negative prompt from what you normally get (on the right, with weight 1.0) to nothing, as if the negative prompt was empty (on the left, with weight 0.0):
Prompt: portrait of zimby anton fadeev cyborg propaganda poster
Params: Steps: 30, Sampler: DPM++ SDE Karras, CFG scale: 7.5, Seed: 918, Size: 512x640, Model: deliberate_v2
Negative Prompt: Male
Prompt: portrait of zimby anton fadeev cyborg propaganda poster
Params: Steps: 30, Sampler: DPM++ SDE Karras, CFG scale: 7.5, Seed: 918, Size: 512x640, Model: deliberate_v2
Negative Prompt: Female
Why Use This?
This method was originally intended for decreasing the effect of the negative prompt, which is very hard or at times impossible to do with the currently available methods like Better Prompting™, Attention/Emphasis (using the '(prompt:weight)' syntax), Prompt Editing (using the [prompt1:prompt2:when] syntax), etc. But you can also use it with values higher than 1 and it will boost your negative prompt in its own style (you might need to lower your CFG scale a bit if you do that).
Here is the first example compared to using the '(negative prompts: weight)' syntax (i.e. bottom row is (negative prompt:0),(negative prompt:0.25),etc.:
Please have a look at the examples in the comparisons section if you want to know how it's different from using '(prompt:weight)' and check out the discussion here if you need more context.
Installation
Open SD WebUI > Go to Extensions tab > Go to Available > Press the big button > Find 'Negative Prompt Weight' in the list > Click Install
Or manually clone this repo into your extensions folder:
git clone "https://github.com/muerrilla/stable-diffusion-NPW" extensions/stable-diffusion-NPW
Usage
After installing, you can locate the new parameter "Negative Prompt Weight" in the extentions area of txt2img and img2img tabs.
Limitations
Doesn't work with SDXL yet.
More Comparisons and Stuff
Here are some comparisons between NPW and Attention/Emphasis. So, top row is using NPW and bottom row is using the (Negative Prompt: weight) syntax with the same weights.
Prompts: a close up portrait of a cyberpunk [knight|lobster], [lobster| ] armour, cyberpunk!, fantasy, elegant, digital painting, artstation, concept art, matte, sharp focus, art by josan gonzalez
Params: Steps: 30, Sampler: DPM++ 2M Karras, CFG scale: 10, Seed: 6, Size: 512x640, Model: deliberate_v2
Negative Prompt: red
Negative Prompt: samurai pink cg
Negative Prompt: custom TI embedding
How It's Done
At runtime a new learned conditioning tensor empty_uncond is made from an empty prompt. Then at every step, inside the denoiser callback, the scheduled uncond tensor of the denoiser (which is based on whatever prompt hijinks were passed to the parser) is lerped with the empty_uncond to weaken it's effect. The lerp function can instead be given a parameter bigger than 1, and it will boost the effect of the negative prompt like the CFG scale does for the positive.