Codex Image Generation

⚠️ 美术必读 — Size 限制：Codex CLI 最大输出 ~1.57MP（1254×1254 级别），所有尺寸都会被卡在这个上限内。4K/FHD/2K 都会降级，不会真的输出那些尺寸。详见下方安全尺寸表。

Size 限制速查

结论：游戏 UI 素材推荐用 1K（方图）或 1536x1024（横版），不要用 FHD/4K/720p 等标识。

Quick Reference

Size Keys (gen_size.sh)

核心约束：Codex CLI 所有输出被强制限制在 ~1.57MP 以内。4K / FHD / 2K / 720p 等大尺寸标识均会被降级处理，只有 1K、1536x1024、9:16、4:3 能保持原始比例不缩放。

Generating Images

Single image

bash ~/.openclaw/skills/codex-imggen/scripts/generate.sh \
  "A fantasy sword with golden blade on white background (#ffffff), flat vector art style" \
  /tmp/my-images

With size control

bash ~/.openclaw/skills/codex-imggen/scripts/gen_size.sh \
  "1K" \
  "A medieval castle on a hill at sunset" \
  /tmp/my-images

Batch game UI assets (proven 2026-05-21)

bash ~/.openclaw/skills/codex-imggen/scripts/batch_generate.sh \
  "flat vector art style, white background (#ffffff), each icon approximately 256x256 pixels, consistent 2px gold (#d4af37) border, same lighting angle, centered subjects" \
  6 \
  /tmp/my-icons

This generates one combined image with all items in a grid (usually 2x3). See Batch Examples below for tested prompts.

Batch Examples (tested 2026-05-21)

All outputs are single combined images; use ImageMagick to cut apart.

RPG Icons (3x2 grid, 1024×1536)

Generate a set of 6 RPG game UI icons in a 3x2 grid (2 columns, 3 rows), all in the same flat vector art style with a white background (#ffffff). Each icon approximately 256x256 pixels in combined image. Icons: (1) sword with golden blade, (2) shield with silver surface and red cross, (3) red health potion bottle, (4) purple crystal gem, (5) golden 5-pointed star, (6) red heart. All icons share consistent 2px gold (#d4af37) border, consistent padding, same lighting angle, centered subjects.

Cyberpunk (3x2 grid, 1024×1536)

Generate a set of 6 cyberpunk game UI elements in a 3x2 grid (2 columns, 3 rows), all in the same neon glow cyberpunk style. Each element approximately 256x256 pixels in combined image. Elements: (1) circuit board chip icon, (2) glowing cyan hexagon, (3) neon sword, (4) holographic shield, (5) power battery with lightning bolt, (6) digital eye/sensor. White background, neon colors (cyan #00ffff, magenta #ff00ff, yellow #ffff00), glow effects.

Pixel Art Items (2x3 grid, 1536×1024)

Generate a set of 6 pixel art game items in a 2x3 grid (3 columns, 2 rows), authentic retro pixel style. Each item approximately 256x256 pixels in combined image. Items: (1) red potion, (2) green herb/plant, (3) blue mana crystal, (4) golden coin, (5) brown wooden chest, (6) white feather. White background, pixel perfect, 16-bit era style.

Flat Minimal Icons (3x2 grid, 1024×1536)

Generate a set of 6 flat minimalist game UI icons in a 3x2 grid (2 columns, 3 rows). Each icon approximately 256x256 pixels in combined image. Icons: (1) play button (triangle), (2) pause button (two bars), (3) settings cogwheel, (4) home button (house shape), (5) sound on (speaker with waves), (6) sound off (speaker with X). Style: ultra flat, solid colors, no outlines, modern mobile game aesthetic. Colors: flat blue (#4a90d9), flat white, flat gray on white background.

Cutting Apart Batch Output

⚠️ Layout 注意：

• 1024×1536 图片 → 2列 × 3行 → 3x2 layout（每格 512×512）
• 1536×1024 图片 → 3列 × 2行 → 2x3 layout（每格 512×341）

# ✅ 推荐：用 batch_split.py（背景透明 + 网格拆分 + alpha 抠图一气呵成）
python3 ~/.openclaw/skills/sprite-tools/scripts/batch_split.sh \
  /tmp/batch.png 3x2 /tmp/icons/

# layout 格式：rows x cols，第一个数是行数（纵向），第二个数是列数（横向）

Size Accuracy Guide

Reliable:

• 1K / 1:1 / square → 1254×1254
• 2048x1080 → 1727×911 (best 2K match)
• 1536x1024 → 1536×1024 (exact!)
• 2K / 16:9 / FHD → 1672×941
• 9:16 → 941×1672
• 4:3 → 1448×1086

Unreliable (avoid):

• 4K / 3840x2160 → capped at 1672×941 (95% area loss)
• Direct pixel requests like 1920x1080 → degrades to 1672×941
• Small sizes like 512x512 → 1254×1254 (huge inflation)

For precise sizes: generate with semantic description, then post-process with ffmpeg or PIL to crop/resize.

Output Location

All images saved to ~/.codex/generated_images/\x3Csession-id>/. Scripts copy latest to your output dir. Check there if no output dir specified.

Proxy

Proxy (http://127.0.0.1:1080) auto-enabled. Change PROXY variable at top of each script if your proxy differs.

Architecture

Codex CLI → Plus subscription → ~1.57MP fixed output bucket
                                    (8 buckets: 1:1, 16:9, 3:2, 4:3, 9:16, ~17:9)

For >1.57MP: use official gpt-image-2 API (separate skill planned)