Scenario Image

Scenario Image Generation and Editing

Overview

Scenario runs hundreds of image models, split across txt2img (generate from a prompt) and img2img (edit, restyle, inpaint, upscale). The loop is the one the scenario skill teaches. What breaks image runs is the per-model contract: sizing fields, prompt limits, and reference caps differ between two models that do the same job, so read model_schema_get every time. Per-family contracts (sizing families, reference caps, edit modes): scenario-seedream, scenario-gpt-image, scenario-gemini-image, scenario-ideogram, scenario-reve, scenario-luma-image, scenario-mai-image, scenario-grok-imagine-image. Upscaling, grading, effects, expand, resize and the other tool models: see scenario-image-editing. Holding one look across a set: see scenario-consistency. One image from several references, each with one job: scenario-multi-reference. Sprites, icons, and tilesets: see scenario-game-assets. If a sibling skill named here is missing from your available skills, ask the user to install it (npx skills add scenario-labs/skills --skill <name>); unattended, proceed from tool schemas and flag the gap.

Quick reference

Inpainting and outpainting are img2img, not capabilities of their own.

The three fields that fail runs

All three are per-model, so take them from the schema rather than from a previous run:

• Size. Sizing has no common shape: numeric width and height with min, max, and a step to land on; an enum (aspectRatio, a resolution in megapixels or K tiers, a size mixing tiers with pixel pairs); or an aspect ratio alone, which puts an exact pixel target out of reach entirely. Pixels sent to an enum field, or an off-step value, are rejected. When the schema cannot express the size asked for, report what it can reach rather than rounding silently.
• Prompt length. The prompt field's max_length ranges from roughly 2000 characters to 32000. A prompt that fits one model is a 400 on the next.
• References. Name (referenceImages, image), cap, and cardinality all come from the schema, and the name settles none of them: a field called referenceImages is a single scalar file on some models. Pass an array only where the schema says array: true, and there pass one even for a lone asset, since a bare string is dropped silently and the run then succeeds while ignoring the reference. With several references, say in the prompt which is which.

A batch-count field (numOutputs, numImages) repeats one prompt, so it yields variations, not a set. Anything with a per-item difference needs one model_run per item.

Landing an exact size

In-game placements need exact pixels (a 210x600 banner, a 256x256 icon), which a generative model may not support directly. Numeric sizing fields snap to a grid (a step of 16 is common, with min and max bounding the range), enum fields offer fixed tiers, and some members silently replace a request below their floor: 512x128 came back as 1408x480 on one member, with no error. When the target is unsupported, generate at the nearest reachable size at or above it, matching the ratio where possible and respecting every schema limit (1024x1024 for a 256x256 icon on a member with a 1K floor; 224x640 for a 210x600 banner only if both dimensions meet that member's limits), then finish with model_scenario-resize-image, a fixed id since it is Scenario's single deterministic exact-dimension resize tool and discovery would only re-derive it: images as an array even for one asset, width and height, and fit cover to fill the box and center-crop the overflow or stretch for exact dimensions at the cost of distortion (contain, the default, can return a smaller image than the box). Choose a larger source only for an explicit quality requirement or documented model guidance, not an assumed family sweet spot. Confirm with asset_get. Downscaling can make softness less visible; resizing upward cannot recover missing detail.

Blur has the same discipline: several members default to a 1K tier with a higher one in the schema, so set the resolution or quality tier explicitly for a new generation. To preserve an approved frame, upscale the exact keeper (scenario-image-editing); re-running its recipe can change the image. On a custom-trained member, check guidance and step count against its schema and model guidance before increasing them. When outputs feel literal, split the prompt into what is fixed and what the model may invent and say so. Invented details must obey the fixed constraints too (no decorative runes in a text-free brief); prompt_spark expands a thin brief into an on-model one before the run.