1hew-ComfyUI-1hewNodes/web/docs/1hew_ImageBatchGroup/en.md

Image Batch Group - Windowing with overlap and fill

Node Purpose: Image Batch Group partitions an image batch into windows of size batch_size with configurable overlap. Controls how the last window is handled (drop, keep remaining, backtrack to end, or fill with color), and reports start indices, window counts, and valid counts.

Inputs

Name	Port	Type	Default	Range	Description
image	-	IMAGE	-	-	Input image batch.
batch_size	-	INT	81	1-1024	Window size per group.
overlap	-	INT	0	0-1024	Overlap frames between consecutive windows.
last_batch_mode	-	COMBO	backtrack_last	drop_incomplete / keep_remaining / backtrack_last / fill_color	Strategy for the final window.
color	-	STRING	1.0	grayscale/HEX/RGB/named	Background color when fill_color is used; supports 0.0-1.0, R,G,B, HEX, and names (red, white, etc.).

Outputs

Name	Type	Description
image	IMAGE	When fill_color, returns the padded batch; otherwise returns only original frames.
group_total	INT	Total number of groups.
start_index	LIST(INT)	Start indices for each window.
batch_count	LIST(INT)	Window sizes (after strategy application).
valid_count	LIST(INT)	Real frames per window (accounts for padding).

Features

• Parameter validation: prevents invalid overlaps; in backtrack_last mode allows overlap <= batch_size, otherwise requires overlap < batch_size.
• Start index computation: step size batch_size - overlap; guarded when step would be non-positive.
• Modes:
  • drop_incomplete: exclude incomplete tail windows.
  • keep_remaining: include the last partial window as-is.
  • backtrack_last: shift final start to align the last full window to the end.
  • fill_color: pad with solid frames so all windows are full-size; returns the padded batch.
• Color parsing: accepts grayscale floats, R,G,B (0–1 auto-converted), HEX, single-letter shortcuts (r/g/b/c/m/y/k/w), and named colors.
• Valid counts: last window reflects actual, non-padded frames when applicable.

Typical Usage

• Sliding windows with overlap: set batch_size=M, overlap=K to build rolling windows for sequence processing.
• Keep only full windows: set last_batch_mode=drop_incomplete.
• Align final window to end: set last_batch_mode=backtrack_last.
• Pad to uniform window size: set last_batch_mode=fill_color and specify color.

Notes & Tips

• When fill_color, alpha channel (if present) is set to 1.0; grayscale padding uses the average of RGB.
• valid_count helps distinguish real versus padded frames, especially in the last window.