ideogram4-prompt-builder/docs/inference.md

Inference Reference

Detailed parameters, sampler presets, supported resolutions, and optimization tips for Ideogram 4 inference.

Sampler Presets

Named presets bundle a step count, per-step CFG schedule, schedule mean (mu), and schedule standard deviation (std) into a single flag:

python run_inference.py \
  --prompt "a cat wearing a tiny top hat" \
  --sampler-preset V4_QUALITY_48 \
  --output out.png

Preset	Steps	CFG schedule	mu	std
V4_QUALITY_48	48	45 steps @ gw=7, then 3 polish steps @ gw=3	0.0	1.5
V4_DEFAULT_20	20	18 steps @ gw=7, then 2 polish steps @ gw=3	0.0	1.75
V4_TURBO_12	12	11 steps @ gw=7, then 1 polish step @ gw=3	0.5	1.75

V4_QUALITY_48 is the default. Fewer steps trade quality for speed. The full registry lives in ideogram4.sampler_configs.PRESETS; add a new entry there to define your own.

Key Parameters

These are the keyword arguments accepted by Ideogram4Pipeline.__call__. The defaults below apply when you call pipe(...) directly; run_inference.py overrides num_steps, guidance_schedule, mu, and std from the chosen sampler preset (see above).

Parameter	Default	Notes
height / width	1024	Must be multiples of 16. Supported range: 256–2048. Aspect ratios up to 6:1 or 1:6.
num_steps	48	More steps = higher quality. The V4_QUALITY_48 preset (48 steps) is a good speed/quality trade-off.
guidance_scale	7.0	Constant guidance weight used when no guidance_schedule is given. Higher = more prompt adherence, lower = more diversity.
guidance_schedule	None	Optional per-step guidance weights (loop-index order: index 0 is the final step). Overrides guidance_scale.
mu	0.5	Logit-normal schedule mean. Auto-adjusted for resolution.
std	1.0	Logit-normal schedule standard deviation.
seed	None	Set for reproducible results.

Supported Resolutions

Ideogram 4 natively supports any resolution where both height and width are multiples of 16, within the range 256–2048 (aspect ratios up to 6:1 or 1:6).

Use case	Resolution	Aspect ratio
Square	1024 × 1024	1:1
Landscape	1536 × 1024	3:2
Portrait	1024 × 1536	2:3
Widescreen	1920 × 1088	~16:9
Ultrawide	2048 × 768	~21:9
Phone wallpaper	1024 × 1792	~9:16
Social banner	1600 × 400	4:1

Resolution buckets use 16-pixel increments, giving fine-grained control over output dimensions.