ComfyUI-MaskArbiter

ComfyUI Mask Arbiter

Mask Arbiter sorts, merges, and selects masks while preserving their original resolution.

Inputs

workflow_mask_arbiter

• sort_by: Keep the initial order, randomize it, merge all masks, or order masks by position or area.
• index: Select an item from the resulting order. Values past the end select the last mask.
• resolution: Maximum evaluation width or height used to accelerate sorting. Use 0 for full resolution. This does not resize outputs.
• average: Use mask centroids for positional sorting instead of the nearest relevant edge or pixel.
• reverse: Reverse the completed order before selecting index.
• masks / mask: Connect either input. The standard mask input takes precedence when both are connected.

Outputs

• selected_mask: The mask selected by index, returned as a standard ComfyUI mask batch.
• ordered_masks: All masks in their resulting order. merged produces a one-item list.

[!NOTE] ComfyUI-MaskArbiter is packaged with a modified version of the GroundingDinoSAM2Segment node from ComfyUI-SAM2. Look for "GroundingDinoSAM2SegmentList." This version of the node outputs a list of masks that you can feed into Mask Arbiter. It also enables support for SAM 2.1 models. You do not need this if you are using SAM 3 instead.

An empty tensor batch such as [0, H, W] returns a black [1, H, W] selected mask and preserves the empty batch on ordered_masks.

Additional node

GroundingDinoSAM2SegmentList runs GroundingDINO detection followed by SAM2 segmentation and returns detected image/mask items.

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Inputs

• mask OR masks: A list of masks to process with Mask Arbiter, such as the outputs of Segment Anything. Supports either datatype for compatibility with different masking nodes.
• sort_by: The method of sorting your masks. Possible options include leftmost (sort left to right), topmost (sort top to bottom), innermost (prioritize closest to center of your image), largest (sort by pixel area occupied), initial (do not sort), random (sort randomly), and merged (combine all masks and merge into one.)
• reverse: Reverses the mask list order after sorting. For example, if you sort by leftmost and enable reverse, you'll get the rightmost subject.
• index: The individual mask to return after sorting, zero-indexed.

Outputs

• MASK: A mask of the selected index after sorting.
• MASKS: The entire mask list after sorting.

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This script was adapted from the [txt2mask] shortcode of Unprompted, my Automatic1111 extension.