Sprite Sheet Python Library

Overview

The Sprite Sheet Python Library adds sprite sheet processing capabilities to your Python interpreter.

This library provides method to find the sprites that are packed in a single image, and to return their position in this image (bounding boxes).

Concepts

Sprite

A sprite is a small raster graphic (a bitmap) that represents an object such as a character, a vehicle, a projectile, etc.

Sprites are a popular way to create large, complex scenes as you can manipulate each sprite separately from the rest of the scene. This allows for greater control over how the scene is rendered, as well as over how the players can interact with the scene.

Sprites are mainly used in 2D video games, such as Shoot'em up in which the hero combats a large number of enemies by shooting at them while dodging their fire:

Cannon Fodder	Commando	Metal Slug

Sprite Sheet

It is not uncommon for games to have tens to hundreds of sprites. Loading each of these as an individual image would consume a lot of memory and processing power. To help manage sprites and avoid using so many images, many games use sprite sheets (also known as image sprites).

A sprite sheet consists of multiple sprites in one image. In other words, sprite sheets pack multiple sprites into a single picture. Using sprite sheet, video game developers create sprite sheet animation representing one or several animation sequences while only loading a single file:

Sprite Bounding Box

A frame (bounding box) can be used to delimit the sprite in the sprite sheet. This bounding box is defined with two 2D points top_left and the bottom_right, which their respective coordinates x and y are relative to the top-left corner of the sprite sheet's image.

For example:

Sprite Mask

The mask of a sprite defines the 2D shape of the sprite. For example, the sprite sheet metal_slug_sprite_standing_stance.png contains the 3 following sprites:

The masks of these sprites are respectively:

Installation

Install the Sprite Sheet Python Library with pip:

$ pip install sprite-sheet

Usage

For example, let's consider the image file sprite_example.png zoomed-in hereafter:

>>> from spriteutil.spritesheet import SpriteSheet
>>> sprite_sheet = SpriteSheet('metal_slug_single_sprite.png')
>>> sprites, label_map = sprite_sheet.find_sprites(background_color=(255, 255, 255))
>>> len(sprites)
1
>>> for label, sprite in sprites.items():
...     print(f"Sprite ({label}): [{sprite.top_left}, {sprite.bottom_right}] {sprite.width}x{sprite.height}")
Sprite (1): [(0, 0), (29, 37)] 30x38
>>> import pprint
>>> pprint.pprint(label_map, width=120)
[[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,0,1,1,1,1,0,0,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0],
 [0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0],
 [0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0],
 [0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0],
 [0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1],
 [0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1,1],
 [0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,1,1,1,1,0],
 [0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,1,1,0,0],
 [0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0],
 [0,0,0,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [0,0,1,1,1,1,1,1,1,1,0,0,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,1,0,0,0,0,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0],
 [0,1,1,1,1,1,1,0,0,0,0,0,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,0,0,0,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0],
 [1,1,1,1,1,1,1,1,1,0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0,0]]