File:Rolling shutter effect animation.gif
Summary
| Description |
English: The effect of a rolling shutter on a spinning disc simulated. The jagged appearance is due to the small number of rows; the higher number of rows in a real camera results in smoother curves. |
| Date | |
| Source | Own work based on: Rolling shutter effect.svg |
| Author | cmglee |
| GIF development |
Python source
The frames were rendered using Python 2 with pypng below, converted to GIF, made into a GIF animation, and optimised with Ezgif.
#!/usr/bin/env python
import png, math, os, functools, operator
def draw_pixel(pixelsss, x, y, rrggbb):
pixelsss[y][x][0] = int(rrggbb[-6:-4], 16)
pixelsss[y][x][1] = int(rrggbb[-4:-2], 16)
pixelsss[y][x][2] = int(rrggbb[-2: ], 16)
def write_png(path, pixelsss, width, height=None, alpha=False):
print('> %s' % (path))
f_out = png.Writer(width=width, height=width if height is None else height, alpha=alpha)
return f_out.write_array(open(path, 'wb'),
functools.reduce(operator.iconcat,
functools.reduce(operator.iconcat, pixelsss, []), []))
def compute_colour(fraction, deg):
return colours[int((deg + 720 - 360 * fraction + 0.5) / 60) % 6]
n_frame = 60
w_frame = 400
h_frame = 200
radius = 99
w_frame2 = w_frame // 2
diameter = radius * 2
colours = ['ff0000','cc9900','00cc00','3399ff','6666ff','cc33ff']
basename = os.path.splitext(os.path.basename(__file__))[0]
cumulsss = [[[255 for c in range(3)] for x in range(diameter)]
for y in range(diameter)]
for i_frame in range(n_frame + 1): ## 0 = prepare cumulative image
framesss = [[[255 for c in range(3)] for x in range(w_frame)]
for y in range(h_frame)]
for y in range(-radius, radius):
out_y = y + radius
out_y_end = (diameter - 1) * i_frame // n_frame
for x in range(-radius, radius):
if x * x + y * y < radius * radius:
out_x = x + radius
deg = math.degrees(math.atan2(y, x))
colour_cumul = compute_colour((y + radius + 1.0) / (diameter - 1), deg)
colour_disc = compute_colour(float(i_frame) / n_frame , deg)
if i_frame > 0: draw_pixel(framesss, out_x + 1, out_y, colour_disc )
else: draw_pixel(cumulsss, out_x , out_y, colour_cumul)
if out_y <= out_y_end: framesss[out_y][w_frame2:w_frame2 + diameter] = cumulsss[out_y]
for dy in [-1, 0]:
framesss[out_y_end + dy][1] = framesss[out_y_end + dy][w_frame - 2] = [0,0,0]
for dy in [-2, 1]:
framesss[out_y_end + dy][1:w_frame - 1] = [[0,0,0] for i in range(w_frame - 2)]
if i_frame > 0:
write_png(r'F:\%s\%02d.png' % (basename, i_frame), framesss, w_frame, h_frame)
else:
write_png(r'F:\%s\00.png' % (basename), cumulsss, diameter, diameter)
Licensing
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
