asc-screenshot-resize

# asc screenshot resize Use this skill to prepare screenshots for App Store Connect. Do not rely on a hard-coded dimension table in this skill; the CLI owns the current size matrix. ## Source of truth Always discover current accepted sizes from `asc` first: ```bash asc screenshots sizes --output table asc screenshots sizes --all --output table ``` For local validation before upload: ```bash asc screenshots validate --path "./screenshots/iphone" --device-type "IPHONE_65" --output table asc screenshots validate --path "./screenshots/ipad" --device-type "IPAD_PRO_3GEN_129" --output table ``` Common current device-type anchors: - `IPHONE_65` for the common 6.5-inch iPhone screenshot set. - `IPAD_PRO_3GEN_129` for the common 12.9/13-inch iPad screenshot set. Run `asc screenshots sizes --all` when targeting other display types such as 6.9-inch iPhone, Apple TV, Mac, Vision Pro, iMessage, or Watch. ## Workflow ### 1. Sanitize filenames macOS screenshots can contain hidden Unicode spaces that make tools fail with "not a valid file". Sanitize before batch work: ```bash python3 -c " import os for f in os.listdir('.'): clean = f.replace('\u202f', ' ') if f != clean: os.rename(f, clean) print(f'Renamed: {clean}') " ``` ### 2. Inspect dimensions and metadata ```bash sips -g pixelWidth -g pixelHeight screenshot.png sips -g hasAlpha -g space screenshot.png ``` App Store Connect rejects screenshots with alpha transparency. Strip alpha by round-tripping through JPEG: ```bash sips -s format jpeg input.png --out /tmp/asc-screenshot-no-alpha.jpg sips -s format png /tmp/asc-screenshot-no-alpha.jpg --out output.png rm /tmp/asc-screenshot-no-alpha.jpg ``` Batch-strip alpha from PNGs: ```bash for f in *.png; do if sips -g hasAlpha "$f" | grep -q "yes"; then sips -s format jpeg "$f" --out /tmp/asc-screenshot-no-alpha.jpg sips -s format png /tmp/asc-screenshot-no-alpha.jpg --out "$f" rm /tmp/asc-screenshot-no-alpha.jpg echo "Stripped alpha: $f" fi done ``` ### 3. Resize only after choosing a target from asc Pick a width and height from `asc screenshots sizes --all`. `sips -z` takes height first, then width: ```bash # Example: portrait IPHONE_65 1284 x 2778 sips -z 2778 1284 input.png --out output.png ``` Batch resize to a chosen target: ```bash mkdir -p resized for f in *.png; do sips -z 2778 1284 "$f" --out "resized/$f" done ``` ### 4. Validate outputs with asc ```bash sips -g pixelWidth -g pixelHeight -g hasAlpha resized/*.png asc screenshots validate --path "./resized" --device-type "IPHONE_65" --output table ``` ### 5. Upload only after validation ```bash asc screenshots upload --version-localization "LOC_ID" --path "./resized" --device-type "IPHONE_65" --dry-run --output table asc screenshots upload --version-localization "LOC_ID" --path "./resized" --device-type "IPHONE_65" ``` ## Guardrails - Treat `asc screenshots sizes --all` as authoritative; Apple size requirements change. - Do not stretch screenshots across incompatible aspect ratios unless the user accepts the visual tradeoff. - Always output to a separate file or directory to preserve originals. - Screenshots must be PNG or JPEG and must not include alpha transparency. - Convert Display P3 or other color spaces to sRGB when needed: ```bash sips -m "/System/Library/ColorSync/Profiles/sRGB IEC61966-2.1.icc" input.png --out output.png ``` - Prefer `asc screenshots validate` over visual inspection before upload.