File:Line pixel subpixel aa.gif

Line_pixel_subpixel_aa.gif (384 × 128 pixels, file size: 95 KB, MIME type: image/gif, looped, 64 frames, 3.2 s)

Summary

Description
English: This is a simple animation, created with Python, that compares side-by-side pixel precision vs subpixel precision vs anti-aliasing in line rasterization.
Date
Source Own work
Author Drummyfish
Source code
InfoField
# Simple animation showing pixel vs subpixel accuracy.
# by Miloslav Ciz, released under CC0 1.0

from PIL import Image
import math

SCALE = 8

FRAMES = 64

RESOLUTION = (48,16)

img = Image.new("RGB",(RESOLUTION[0] * SCALE,RESOLUTION[1] * SCALE),"white")

pixels = img.load()

def setPixel(x, y, c):
  for b in range(SCALE):
    for a in range(SCALE):
      pixels[x * SCALE + a,y * SCALE + b] = (c,c,c)

def drawLine(p0, p1, aa):
  slope = (p1[1] - p0[1]) / float(p1[0] - p0[0])

  for i in range(int(p1[0] - p0[0] + 1)):
    x = int(p0[0] + i) if aa else round(p0[0] + i)
    y = p0[1] + i * slope

    c = int(255 * (y % 1)) if aa else 0

    y = int(y) if aa else round(y)

    setPixel(x,y,c)

    if aa:
      setPixel(x,y + 1,255 - c)

for f in range(FRAMES):
  img.paste((255,255,255),(0,0,img.size[0],img.size[1]))

  t = f / float(FRAMES) * math.pi * 2

  x0 = 0
  x1 = 15

  y0 = 8 + math.sin(t) * 5
  y1 = 7 + math.cos(t) * 3

  drawLine((x0,round(y0)),(x1,round(y1)),False)
  drawLine((x0 + RESOLUTION[0] / 3,y0),(x1 + RESOLUTION[0] / 3,y1),False)
  drawLine((x0 + 2 * RESOLUTION[0] / 3,y0),(x1 + 2 * RESOLUTION[0] / 3,y1),True)

  for i in range(RESOLUTION[1] * SCALE):
    pixels[int(RESOLUTION[0] * SCALE / 3),i] = (0,0,0)
    pixels[int(2 * RESOLUTION[0] * SCALE / 3),i] = (0,0,0)

  img.save("out" + str(f).zfill(2) + ".png")

Licensing

I, the copyright holder of this work, hereby publish it under the following license:
Creative Commons CC-Zero This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.

Captions

Animation comparing pixel precision vs subpixel precision vs anti-aliasing.

Items portrayed in this file

depicts

3 February 2023

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current13:20, 3 February 2023Thumbnail for version as of 13:20, 3 February 2023384 × 128 (95 KB)DrummyfishFix rounding
12:59, 3 February 2023Thumbnail for version as of 12:59, 3 February 2023384 × 128 (95 KB)DrummyfishUploaded own work with UploadWizard

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