thash 1.0.0

A very compact representation of an image placeholder (thumbhash, RGBA-safe fork)

thash

A Python port of the thumbhash encoder by Evan Wallace.

This is an independently published fork of thumbhash by Justin Forlenza. It fixes the long-standing alpha-channel crash (operator precedence bug in rgba_to_thumb_hash — see upstream issue #1) so that images with transparency no longer raise type tuple doesn't define __round__ method.

Installation

pip install thash

Optionally install with pillow support:

pip install thash[pillow]

Usage

Encode an RGBA array to a ThumbHash:

from thash import rgba_to_thumb_hash


rgba = [100, 85, 15, 255, 100, 84, 32, 255, ...]
width = 100
height = 75

thumb_hash = rgba_to_thumb_hash(width, height, rgba)
# [86, 8, 10, 13, 128, 22, 234, 86, 111, 117, ...]

Open an image with pillow, scale it down to fit in a 100x100 box and encode to a ThumbHash:

from thash import image_to_thumb_hash

thumb_hash = image_to_thumb_hash('image.jpg')
# [86, 8, 10, 13, 128, 22, 234, 86, 111, 117, ...]

Features

This library currently handles the conversion of images to hashes, not the reverse.

Credits

Original Python port: Justin Forlenza — justinforlenza/thumbhash-py

Original ThumbHash algorithm: Evan Wallace — evanw/thumbhash