Presets & Configuration Guide

PixelTamp replaces complicated encoding dials with three opinionated, carefully calibrated presets.

My professional background is in web development and I have spend years (multiple decades now!) using photo editing apps and CLI compression tools to optimise images before publishing them online. It’s been a repetitive laborious task for too long and in practice it really only needs a very small number of output options, so what this app does comes from a lot of experience.

These specs are for the nerds out there…

The Three Compression Presets

1. Tamped (Default & Recommended)

Goal: The sweet spot between visual fidelity and compact web payload.
JPEG: 48% quality target with ImageIO colour sharing optimisation.
PNG: 8-bit palette quantisation (256 colours) with Floyd-Steinberg error diffusion dithering.
WebP: 85% lossy quality encoding via embedded Google libwebp.
Video: 0.70 hardware quality score, 192 kbps AAC audio, H.264 web profile with faststart MOOV atom.

2. Lossless (Maximum Fidelity)

Goal: Pure mathematical or visually imperceptible optimisation without altering visible pixel quality.
JPEG: Visually lossless high-fidelity encoding with metadata stripping and colour sharing optimisation.
PNG: Full 24/32-bit lossless Deflate stream optimisation without palette reduction.
WebP: 100% mathematical lossless WebP encoding.
Video: 0.90 high-fidelity hardware quality score, 192 kbps AAC audio with faststart MOOV atom.

3. Aggressive (Maximum Byte Savings)

Goal: High compression for bandwidth-constrained environments, email newsletters, or mobile-first applications.
JPEG: 35% quality target for maximal byte reduction.
PNG: 8-bit aggressive palette quantisation (128 colours) with dithering.
WebP: 65% lossy quality encoding via embedded libwebp.
Video: 0.50 compact hardware quality score, 128 kbps AAC audio with faststart MOOV atom.

You are encouraged to inspect examples of these compressions on the website’s home page.

Independent Dimension & Resolution Controls

Resolution and dimension constraints are independent of the compression preset:

Images: Select Original Size, 2560px (default), 1920px, or 1024px.
Videos: Select Original Resolution (default), 4K (3840×2160), 1080p (1920×1080), or 720p (1280×720).

Any preset can be paired with any resolution mode. PixelTamp never upscales assets that are already smaller than the chosen threshold.

Output Saving Strategies

PixelTamp strictly follows a non-destructive policy: it will never overwrite your original source files.

You can configure output destinations in Settings (Cmd + ,):

Option 1: Suffix Alongside Original (Default)

Tamped assets are written to the exact same folder as the source file, appended with a customisable suffix (default: _tamped).

Example: photo.jpg → photo_tamped.jpg
If an empty suffix is entered, PixelTamp automatically enforces _tamped as a safeguard against overwriting.

Option 2: Custom Designated Folder

You can select a dedicated folder (such as ~/Downloads/Optimised or ~/Desktop/Tamped) where all processed media will be saved.

Preserves original filenames when saved to a separate directory.
If the output path would conflict with the source file, a numbered suffix is added automatically.