Eric Qwen-Edit Apply Mask

Not every node in a pack needs to be clever. Eric Qwen-Edit Apply Mask is a plain mask-based compositor: foreground image where the mask is white, background where it's black, blended output. If you've used any ComfyUI masking node, you know exactly what this does - and it's in this pack because the fancier nodes need it.

You'll reach for it in two places. First, after Eric Qwen-Edit Delta: Delta gives you a change_mask, and Apply Mask is the natural way to force a manual blend - feed it the original as background, the edit as foreground, and Delta's mask (or your own input_mask) as the blend mask. Second, as a standalone utility whenever you want a feathered merge of two images without dragging a full compositing suite into the graph.

The inputs

• foreground - shown in the white areas of the mask.
• background - shown in the black areas.
• mask - the blend mask. This is the whole job: white = foreground, black = background.
• blur_mask - optional (0–50, default 0). Extra Gaussian blur on the mask for a softer blend. A few pixels here is the difference between a hard cut and a gentle merge when your source mask has jagged edges.

Output: a single image.

Practical notes

• The mask doesn't have to match the images' resolution - ComfyUI resizes it to the image size in the blend, but if your mask is low-res the edges will be blocky. Blur it with blur_mask to compensate.
• This is a full-replacement blend, not an alpha mix. There's no "opacity" dial - blur_mask softens the edge, but the white regions are fully foreground and black regions fully background. For partial transparency you'd want to chain a Strength/Multiply node on the mask first.
• It pairs beautifully with Delta. That's the pack's own intended composition: keep the original's untouched pixels, drop the AI edit in where the change mask says.

Installing it

ComfyUI Manager → "Eric Qwen-Edit", or:

cd ComfyUI/custom_nodes
git clone https://github.com/EricRollei/Eric_Qwen_Edit_Experiments.git

Restart. It needs no model at all - pure tensor image math - so it works in a completely unloaded graph. That's part of why it's handy: you can use it as a generic utility even if you never load Qwen-Edit.

Troubleshooting

• Black or white box instead of a blend - your mask is probably all one value, or wired backwards (black = foreground swaps the blend). Check the mask's values and the socket order.
• Visible seam down the middle - the mask is hard-edged; raise blur_mask (or blur the mask upstream) to feather the boundary.
• Foreground/background reversed - invert the mask, or swap the two image inputs; whichever is easiest to see in your graph.