Flex Image Bloom ⚡🅡🅞🅣🅘

Bloom is the glow that spills off bright areas of an image - the halo around a streetlight, the soft blowout around a sun-lit edge. FlexImageBloom does that, but it's built as one of RyanOnTheInside's "Flex" nodes, which means every knob on it can optionally be driven by a reactive Feature (audio, motion, brightness, whatever you've extracted elsewhere in the pack) instead of sitting at one fixed value for a whole sequence.

How it works

Under the hood it's a multi-pass bloom: pixels brighter than threshold (0.7 default) get treated as light sources, blurred by blur_amount, and blended back over the image at a strength set by intensity. num_passes stacks that blur multiple times at different radii, which is what gives bloom its layered, atmospheric look rather than a single flat glow ring - more passes cost more compute but read as noticeably richer. color_bleeding lets bright colors smear into their neighbors (the classic chromatic "hot" look around overexposed highlights), and falloff controls how sharply the glow fades with distance from its source - low values spread further, high values stay tight and punchy.

The one genuinely distinctive feature here is opt_normal_map - an optional normal map input that, if connected, makes the bloom "surface-aware": light scatters differently depending on the surface geometry the normal map encodes, rather than treating the image as flat. It's a small addition but it's the difference between bloom that looks pasted on top and bloom that reads as actually interacting with the scene's lighting.

Like every Flex image node, feature_param decides which one setting an optional feature is allowed to modulate (choices: intensity, threshold, blur_amount, num_passes, color_bleeding, falloff, or None to disable modulation entirely), feature_mode picks whether that modulation is relative (nudges around your base value) or absolute (recomputes from the feature directly), feature_threshold gates when it kicks in, and the top-level strength scales how hard it's allowed to push.

Inputs and outputs that matter

• images - required, the sequence you're blooming.
• threshold, blur_amount, intensity - the three settings that shape 90% of the look; start here before touching anything else.
• opt_normal_map (optional IMAGE) - for surface-aware light scatter.
• opt_mask (optional MASK) - restricts where the bloom applies, if you only want part of the frame glowing.

Output is a single IMAGE.

How to install it

Via ComfyUI Manager, search "RyanOnTheInside." Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/ryanontheinside/ComfyUI_RyanOnTheInside
cd ComfyUI_RyanOnTheInside
pip install -r requirements.txt

then restart. No model downloads needed - this is a pure image-processing effect, not a diffusion model.

Common issues & troubleshooting

Bloom looks harsh or blocky instead of soft. That's almost always blur_amount too low relative to your image resolution, or num_passes set to 1 - a single low-radius pass reads as a hard glow ring rather than a soft wash. Bump num_passes and blur_amount together before touching anything else.

Runs noticeably slower than other Flex image nodes. num_passes (up to 8) is the direct multiplier on cost - each pass is another blur over the frame. If you're iterating quickly, drop it low, then raise it once you've settled on threshold/intensity.

Nothing glows at all. Check threshold against your actual image's brightness range - if nothing in the frame exceeds it, there's no light source for the bloom to build from. Lower it, or check that your image isn't already low-contrast/dim going in.

opt_normal_map seems to do nothing. It only has an effect when connected - without it, bloom falls back to treating the image as flat, which is still a perfectly normal way to use this node.