hybrid-image-search-demo Dev Log #15 — Removing Tone Count, Unifying A/B Naming

Thu, 16 Apr 2026 00:00:00 +0900

Overview

This session focused on fully removing the tone_count system across the entire project and unifying generated image naming to a clean A/B pair. The change touched backend logic, existing DB rows, and the frontend UI, resulting in 7 commits. A deploy environment issue and an angle/lens-only regeneration bug were also fixed along the way.

Previous: hybrid-image-search-demo Dev Log #14

Summary of Changes

Why Remove Tone Count?

The original design managed the number of tone (color) variants per generation via a tone_count parameter. In practice, two variants (A and B) were always sufficient. The tone count concept added unnecessary complexity to both the UI and the prompt construction pipeline. This session removes it entirely.

flowchart LR
 A["Before: tone_count=N"] -->|"Removed"| B["Fixed A/B pair"]
 B --> C["Simpler prompts"]
 B --> D["Cleaner UI labels"]
 B --> E["DB migration"]

DB Migration (Alembic)

Existing rows in the injection_reason column carried suffixes like _tone2 or _tone3. An Alembic migration strips these suffixes from all existing rows. The parsing logic in app_utils.py was also updated to ignore any lingering suffixes.

Backend Changes

app_utils.py — Removed tone_count suffix appending logic; added suffix stripping during parsing
routes/generation.py — Removed tone_count parameter
generation/injection.py — Removed tone ratio logic
generation/prompt.py — Enriched the B variant with more detail in the prompt
routes/history.py — Added backward-compatible tone suffix handling for history queries
schemas.py — Removed tone_count field

Frontend Changes

App.tsx — Removed tone count badges, unified to A/B naming
GeneratedImageDetail.tsx — Removed tone-related labels
api.ts — Removed tone_count parameter

Angle/Lens-Only Regeneration Fix

When regenerating with only an angle or lens change (no attribute injection), the prompt was not constructed correctly. This was fixed by explicitly handling the angle/lens-only case in the generation pipeline.

Deploy Script Fix

The uv binary installs to ~/.local/bin on EC2, but the deploy script’s PATH did not include this directory, causing deployment failures. Fixed by adding it to PATH in the script.

Commit Log

#	Scope	Description
1	db	Alembic migration to strip tone_count suffix from existing injection_reason rows
2	gen	Stop appending tone_count to the reason string
3	history	Strip tone_count suffix before parsing category from reason
4	ui	Remove tone count badge from cards, use A/B only
5	ui	Replace remaining tone labels with A/B naming
6	deploy	Add ~/.local/bin to PATH for uv on EC2
7	gen	Remove tone ratio entirely, fix angle/lens-only regen, enrich B variant detail

Insights

Incremental removal is safer — Rather than deleting tone_count in one massive commit, the work was split into DB migration, backend logic, then frontend. Each step could be verified for backward compatibility with existing data.
A/B beats N variants — From a user perspective, “A / B” is far more intuitive than “Tone 3 images.” Reducing choice complexity improves UX.
PATH differences between dev and prod — A classic failure mode: works locally but breaks on EC2. Explicitly setting PATH in deploy scripts is a habit worth building.

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