sloum
/
lid
1
2
Fork 1
Code Issues Pull Requests Releases Wiki Activity

Added a threshold and all mode. Reworked the application into a class and reused relevant code for each dithering method.

This commit is contained in:
sloumdrone 2019-06-05 21:19:17 -07:00
parent c842c03993
commit ce837f1d7e
3 changed files with 182 additions and 153 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
.gitignore vendored Normal file
View File

@ -0,0 +1 @@
oneliner

17
README.md
View File

@ -1,7 +1,7 @@
# Lid
_lo-fi image dithering_
Lid performs fairly basic 1 bit image dithering. It converts an input image to grayscale and then dithers that image. It then optimizes the output and saves the file. The result is a reduced filesize, simple image, great for small apge sizes.
Lid performs fairly basic 1 bit image dithering. It converts an input image to grayscale and then dithers that image. It then optimizes the output and saves the file. The result is a reduced filesize, simple image, great for small page sizes.
## Dependencies
@ -14,8 +14,9 @@ lid [option]... [source path] [output name]
Options:<br>
-f = output format, defaults to the recommended setting: png<br>
-m = mode, available: o4, o9, e. default: o4.
-q = quality, defaults to 90, only affects jpeg/jpg
-m = mode, available: o4, o9, e. default: o4.<br>
-q = quality (0 - 100), defaults to 90, only affects jpeg/jpg<br>
-t = threshold (0 - 255), defaults to image average level. only affects dither mode 't'
source path = a path to an image file you want to dither<br>
output name = the name of the file you would like to output, do not include file extension
@ -24,14 +25,20 @@ Lid works best outputting png files from any input. You will get the smallest fi
### Modes
#### t
This is the lowest quality mode. It produces the smallest file, but at the cost of most detail.
#### o4
This is the lowest quality mode. It will produce the smallest file size. It is a four level ordered dither.
This mode is a noticable difference from the stark two tone appearance of threashold mode. The appearance 'gray' areas make for a slightly more photographic image.
#### o9
This mode produces medium quality dithering, it is still a very noticeable effect but not as harsh as o4. It is a none level ordered dither.
This mode produces medium quality dithering, it is still a very noticeable effect but not as harsh as o4. It is a nine level ordered dither.
#### e
This is the highest quality mode. It uses an error diffusion dither. The file size will be the largest of the bunch, but should still be a good reduction from a regular full color photograph.
#### a
The a, or all, mode is a quick flag to say that you want an image put out in all of the modes. The mode flag value for each will be appended to the filename.
## License
Public domain. Use it, improve it, share it!

317
lid
View File

@ -8,156 +8,148 @@ from PIL import Image
import sys
import os, os.path
# Default dithering: 4 level ordered dither
def ordered_dither_4(r):
im = Image.open(r["path"]).convert("L")
width, height = im.size
new = create_image(width, height)
newpixels = new.load()
class Dither:
def __init__(self, data):
self.source_image = Image.open(data["path"]).convert("L")
self.width, self.height = self.source_image.size
self.pixel_count = self.width * self.height
self.new = self.create_image()
self.new_pixels = self.new.load()
self.output_format = data["-f"]
self.output_name = data["out"]
self.output_quality = data["-q"]
self.threshold = data["-t"]
dots = [
[64, 128],
[192, 0]
]
total_px_count = width * height
counter = 1
last_percent_val = 0
last_hash_val = 0
print("Dither method: ordered (4 levels)\033[?25l")
for row in range(0, height):
for col in range(0, width):
dotrow = 1 if row % 2 else 0
dotcol = 1 if col % 2 else 0
impx = get_pixel(im, col, row)
newpixels[col, row] = int(impx > dots[dotrow][dotcol])
counter += 1
new_percent_val = round(counter / total_px_count * 100)
new_hash_val = round(counter / total_px_count * 10)
if new_percent_val != last_percent_val or new_hash_val != last_hash_val:
print("\r{:>3}% |{:<10}|".format(new_percent_val, "#" * new_hash_val), end="")
last_percent_val = new_percent_val
last_hash_val = new_hash_val
new.save("{}.{}".format(r["out"], r["-f"]), r["-f"].upper(), optimize=True, quality=r["-q"])
print("\033[20C\nFinished! ~ {}/{}.{}\033[?25h".format(os.getcwd(), r["out"], r["-f"].lower()))
# 9 level ordered dither
def ordered_dither_9(r):
im = Image.open(r["path"]).convert("L")
width, height = im.size
new = create_image(width, height)
newpixels = new.load()
dots = [
[0, 196, 84],
[168, 140, 56],
[112, 28, 224]
]
total_px_count = width * height
counter = 1
last_percent_val = 0
last_hash_val = 0
print("Dither method: ordered (9 levels)\033[?25l")
for row in range(0, height):
for col in range(0, width):
if not row % 3:
dotrow = 2
elif not row % 2:
dotrow = 1
else:
dotrow = 0
if not col % 3:
dotcol = 2
elif not col % 2:
dotcol = 1
else:
dotcol = 0
impx = get_pixel(im, col, row)
newpixels[col, row] = int(impx > dots[dotrow][dotcol])
counter += 1
new_percent_val = round(counter / total_px_count * 100)
new_hash_val = round(counter / total_px_count * 10)
if new_percent_val != last_percent_val or new_hash_val != last_hash_val:
print("\r{:>3}% |{:<10}|".format(new_percent_val, "#" * new_hash_val), end="")
last_percent_val = new_percent_val
last_hash_val = new_hash_val
new.save("{}.{}".format(r["out"], r["-f"]), r["-f"].upper(), optimize=True, quality=r["-q"])
print("\033[20C\nFinished! ~ {}/{}.{}\033[?25h".format(os.getcwd(), r["out"], r["-f"].lower()))
# Alternate dither mode
def error_dither(r):
im = Image.open(r["path"]).convert("L")
width, height = im.size
new = create_image(width, height)
newpixels = new.load()
i = im.load()
total_px_count = width * height
counter = 1
last_percent_val = 0
last_hash_val = 0
print("Dither method: error diffusion\033[?25l")
for row in range(0, height):
for col in range(0, width):
newpixels[col, row] = update_error(im, i, row, col)
counter += 1
new_percent_val = round(counter / total_px_count * 100)
new_hash_val = round(counter / total_px_count * 10)
if new_percent_val != last_percent_val or new_hash_val != last_hash_val:
print("\r{:>3}% |{:<10}|".format(new_percent_val, "#" * new_hash_val), end="")
last_percent_val = new_percent_val
last_hash_val = new_hash_val
new.save("{}.{}".format(r["out"], r["-f"]), r["-f"].upper(), optimize=True, quality=r["-q"])
print("\033[20C\nFinished! ~ {}/{}.{}\033[?25h".format(os.getcwd(), r["out"], r["-f"].lower()))
#used for printing progress
self.counter = 1
self.percent_val = 0
self.hash_val = 0
def update_error(im, i, r, c):
w, h = im.size
current = get_pixel(im, c, r)
if current > 128:
res = 1
diff = -(255 - current)
else:
res = 0
diff = abs(0 - current)
mov = [[0, 1, 0.4375],[1, 1, 0.0625],[1, 0, 0.3125],[1, -1, 0.1875]]
for x in mov:
if r + x[0] >= h or c + x[1] >= w or c + x[1] <= 0:
continue
p = get_pixel(im, c + x[1], r + x[0])
p = round(diff * x[2] + p)
if p < 0:
p = 0
elif p > 255:
p = 255
i[c + x[1], r + x[0]] = p
return res
def save_file(self):
output_filename = "{}.{}".format(self.output_name, self.output_format.lower())
self.new.save(output_filename, self.output_format.upper(), optimize=True, quality=self.output_quality)
print("\033[20C\nFinished! ~ {}/{}\033[?25h".format(os.getcwd(), output_filename))
def print_spinner(n):
print("\r|{:<10}|".format("#" * n), end="")
# Create a new image with the given size
def create_image(i, j):
image = Image.new("1", (i, j))
return image
# Default dithering
def ordered_dither_4(self):
dots = [[64, 128],[192, 0]]
print("Dither method: ordered (4 levels)\033[?25l")
for row in range(0, self.height):
for col in range(0, self.width):
dotrow = 1 if row % 2 else 0
dotcol = 1 if col % 2 else 0
px = self.get_pixel(col, row)
self.new_pixels[col, row] = int(px > dots[dotrow][dotcol])
self.update_progress()
self.save_file()
# Get the pixel from the given image
def get_pixel(image, i, j):
width, height = image.size
if i > width or j > height:
return None
def ordered_dither_9(self):
dots = [
[0, 196, 84],
[168, 140, 56],
[112, 28, 224]
]
print("Dither method: ordered (9 levels)\033[?25l")
for row in range(0, self.height):
for col in range(0, self.width):
if not row % 3:
dotrow = 2
elif not row % 2:
dotrow = 1
else:
dotrow = 0
# Get Pixel
pixel = image.getpixel((i, j))
return pixel
if not col % 3:
dotcol = 2
elif not col % 2:
dotcol = 1
else:
dotcol = 0
px = self.get_pixel(col, row)
self.new_pixels[col, row] = int(px > dots[dotrow][dotcol])
self.update_progress()
self.save_file()
def threshold_dither(self):
if not self.threshold:
px_list = list(self.source_image.getdata())
self.threshold = sum(px_list) // len(px_list)
print("Dither method: threshold (set to: {})\033[?25l".format(self.threshold))
for row in range(0, self.height):
for col in range(0, self.width):
px = self.get_pixel(col, row)
self.new_pixels[col, row] = int(px > self.threshold)
self.update_progress()
self.save_file()
def random_dither(self):
pass
def error_diffusion_dither(self):
i = self.source_image.load()
print("Dither method: error diffusion\033[?25l")
for row in range(0, self.height):
for col in range(0, self.width):
self.new_pixels[col, row] = self.update_error(i, row, col)
self.update_progress()
self.save_file()
# Helper for error_diffusion_dither
def update_error(self, i, r, c):
current = self.get_pixel(c, r)
if current > 128:
res = 1
diff = -(255 - current)
else:
res = 0
diff = abs(0 - current)
mov = [[0, 1, 0.4375],[1, 1, 0.0625],[1, 0, 0.3125],[1, -1, 0.1875]]
for x in mov:
if r + x[0] >= self.height or c + x[1] >= self.width or c + x[1] <= 0:
continue
p = self.get_pixel(c + x[1], r + x[0])
p = round(diff * x[2] + p)
if p < 0:
p = 0
elif p > 255:
p = 255
i[c + x[1], r + x[0]] = p
return res
# Create a new image with the given size
def create_image(self):
image = Image.new("1", (self.width, self.height))
return image
# Get the pixel from the given image
def get_pixel(self, col, row):
if col > self.width or row > self.height:
return None
# Get Pixel
pixel = self.source_image.getpixel((col, row))
return pixel
def update_progress(self):
self.counter += 1
new_percent_val = round(self.counter / self.pixel_count * 100)
new_hash_val = round(self.counter / self.pixel_count * 10)
if new_percent_val != self.percent_val or new_hash_val != self.hash_val:
print("\r{:>3}% |{:<10}|".format(new_percent_val, "#" * new_hash_val), end="")
self.percent_val = new_percent_val
self.hash_val = new_hash_val
#---- END Dither class ----#
def display_help():
@ -171,6 +163,7 @@ def display_help():
-f output format. defaults to: png (recommended)
-m dither mode. defaults to: o4. other options: e, o9
-q image quality. defaults to: 90. only has effect on png/jpg
-t threshold. default: image average tone. onls has effect in mode 't'
arguments:
infile path to a valid image file on your system
@ -197,9 +190,10 @@ def parse_input():
argmap = {
"-f": "png", # output format
"-q": 25, # optimization quality
"-m": "o4", # mode, defaults to ordered
"-m": "o4", # mode, defaults to ordered
"-t": None, # threshold
"path": None, # path to file
"out": "lid_file" # output filename
"out": "lid_file" # output filename
}
if len(args) < 1:
print("lid error: expected image filepath, received None")
@ -232,10 +226,20 @@ def parse_input():
elif argmap["-f"] == "jpg":
argmap["-f"] = "jpeg"
if not argmap["-m"] in ["o4", "e", "o9"]:
if not argmap["-m"] in ["o4", "e", "o9", "t", "a"]:
print("lid error: invalid dither mode provided for -m. Options: o4, o9, e. Default: o4")
return None
try:
if argmap["-t"]:
argmap["-t"] = int(argmap["-t"])
if argmap["-t"] < 0 or argmap["-t"] > 255:
print("lid error: threshold value must be between 0 and 255")
return None
except ValueError:
print("lid error: invalid threshold value provided for -m. Must be integer from 0 to 255")
return None
try:
argmap["-q"] = int(argmap["-q"])
if argmap["-q"] < 1 or argmap["-q"] > 100:
@ -254,12 +258,29 @@ def parse_input():
if __name__ == "__main__":
request = parse_input()
if request:
d = Dither(request)
if request["-m"] == "o4":
ordered_dither_4(request)
d.ordered_dither_4()
elif request["-m"] == "o9":
ordered_dither_9(request)
d.ordered_dither_9()
elif request["-m"] == "e":
error_dither(request)
d.error_diffusion_dither()
elif request["-m"] == "t":
d.threshold_dither()
elif request["-m"] == "a":
name = request["out"]
request["out"] = name + "_o4"
d = Dither(request)
d.ordered_dither_4()
request["out"] = name + "_o9"
d2 = Dither(request)
d2.ordered_dither_9()
request["out"] = name + "_t"
d3 = Dither(request)
d3.threshold_dither()
request["out"] = name + "_e"
d4 = Dither(request)
d4.error_diffusion_dither()
else:
print("Unknown mode flag")
sys.exit(2)