Pillar 1 · Model Selection — family deep dive

Types of Diffusion Models

All diffusion models share one trick — start from noise and remove it step by step until content matching the prompt emerges. The types differ in what they generate (image, video, audio) and how much control you get over the result. The step count is your quality-vs-latency-vs-cost knob.

How generation works — and where the cost comes from

The denoising pipeline

Text prompt "red sneaker, studio light" guides every step Random noise the starting canvas Denoiser U-Net or DiT backbone repeat ×20–50 steps Decoder → output image · video frames · audio each step is a full network pass — steps × model size = your latency and GPU bill
"Latent diffusion" (the Stable Diffusion trick): denoise in a compressed latent space instead of raw pixels — that's why it runs on a single consumer GPU.
The step-count knob: distilled "fast" variants (SDXL-Turbo, FLUX.1 schnell, LCM) generate in 1–4 steps instead of 30–50 — near-real-time and much cheaper, at some quality cost. For interactive UX, preview with a fast variant and upscale/refine the chosen result with the full model.

The types you'll actually choose between

Text-to-image

the headline act
text prompt image

Named models

  • Stable Diffusion 1.5 / SDXL / SD3.5 (open-weight)
  • FLUX.1 (open-weight, current quality leader)
  • DALL·E 3 (API), Midjourney (service)
  • Imagen (Google), Firefly (Adobe, licensed training data)

Choose it when

  • Marketing visuals, concept art, mockups
  • Open-weight (SD/FLUX) if you need self-hosting or NSFW-filter control
  • Firefly-class when legal wants clean training-data provenance

Watch out

  • Text rendering inside images is still hit-and-miss
  • IP/brand review loops belong in the workflow

Image editing: img2img, inpainting, outpainting

generation constrained by an existing image
image + mask + prompt edited image

Named models

  • SDXL / FLUX inpainting variants
  • Adobe Generative Fill (Firefly)
  • DALL·E editing API

Choose it when

  • Product-shot variants: swap backgrounds, extend scenes
  • Retouching at scale (e-commerce catalogs)

Watch out

  • Mask quality drives result quality — pair with segmentation (SAM)
  • Edited regions can drift from brand reality — human review for claims-sensitive imagery

Controlled generation: ControlNet, LoRA, IP-Adapter

how brands get consistency
prompt + structure (pose/edges/depth) or learned style on-brand image

Named tools

  • ControlNet (follow a pose, sketch, depth map)
  • LoRA adapters (a learned style/character/product, trained from ~20–50 images)
  • IP-Adapter (match a reference image)

Choose it when

  • Same product/mascot rendered consistently across campaigns
  • Layouts must follow a template or pose
  • This is the diffusion equivalent of fine-tuning — cheap and swappable

Watch out

  • Requires open-weight base models (SD/FLUX) and a pipeline (ComfyUI-class tooling)
  • LoRA on a person's likeness = consent & rights management

Video generation

frames with temporal consistency
text or image short video clip

Named models

  • Sora (OpenAI), Veo (Google)
  • Runway Gen-3, Kling, Pika
  • Stable Video Diffusion (open-weight)

Choose it when

  • Short-form ads, product spins, storyboards/previz
  • Animating existing stills

Watch out

  • Seconds of output = minutes of compute — budget accordingly
  • Physics/continuity glitches; plan human curation
  • Deepfake & disclosure policies (EU AI Act labeling)

Audio, music & speech

the same trick on waveforms
text (± reference voice) speech · music · sound effects

Named models

  • Stable Audio, AudioLDM (sound/music, diffusion)
  • Suno, Udio (music services)
  • ElevenLabs, OpenAI TTS (speech — diffusion + other techniques)

Choose it when

  • Voice-overs, IVR voices, localized audio at scale
  • Background music/SFX without licensing friction

Watch out

  • Voice cloning requires consent workflows
  • Music outputs: check commercial-use terms per service

Cheat sheet: diffusion type → when to buy it

TypeNamed modelsBuy it forOps note
Text-to-imageSDXL, FLUX.1, DALL·E 3, Midjourney, FireflyVisuals from briefsOpen-weight = self-host + customize; APIs = zero infra
Editing / inpaintingGenerative Fill, SDXL-inpaintCatalog retouching, background swapsPair with SAM for masks
Controlled (ControlNet/LoRA)ControlNet, LoRA, IP-AdapterBrand/product consistencyNeeds open-weight base + pipeline tooling
VideoSora, Veo, Runway Gen-3, KlingShort clips, previzExpensive per second; curate outputs
Audio / speechStable Audio, Suno, ElevenLabsVoice-overs, music, SFXConsent + licensing terms per service
Fast/distilled variantsSDXL-Turbo, FLUX schnell, LCMInteractive previews, high volume1–4 steps: cheap & quick, slight quality dip
Diffusion vs GAN in one line: diffusion wins on quality and prompt control; GANs win on single-pass speed and niche pipelines (upscaling, synthetic tabular data) — see the GAN types page.
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