lv_img_conv_py: minimal python port of node module

Create a minimal python port of the node.js module `lv_img_conv`. Only
the currently in use color formats `CF_INDEXED_1_BIT` and
`CF_TRUE_COLOR_ALPHA` are implemented.

Output only as binary with format `ARGB8565_RBSWAP`.

This is enough to create the `resources-1.13.0.zip`.

Python3 implements "propper" "banker's rounding" by rounding to the nearest
even number. Javascript rounds to the nearest integer.
To have the same output as the original JavaScript implementation add a custom
rounding function, which does "school" rounding (to the nearest integer)

Update CMake file in `resources` folder to call `lv_img_conf.py` instead of
node module.

For docker-files install `python3-pil` package for `lv_img_conv.py` script.
And remove the `lv_img_conv` node installation.

---

gen_img: special handling for python lv_img_conv script

Not needed on Linux systems, as the shebang of the python script is read
and used. But just to be sure use the python interpreter found by CMake.
Also helps if tried to run on Windows host.

---

doc: buildAndProgram: remove node script lv_img_conv mention

Remove node script `lv_img_conv` mention and replace it for
runtime-depency `python3-pil` of python script `lv_img_conv.py`.
This commit is contained in:
Reinhold Gschweicher 2023-09-20 21:39:09 +02:00 committed by NeroBurner
parent eac460f030
commit 77546c9fe2
6 changed files with 201 additions and 7 deletions

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@ -11,6 +11,7 @@ RUN apt-get update -qq \
make \
python3 \
python3-pip \
python3-pil \
tar \
unzip \
wget \

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@ -42,7 +42,7 @@ CMake configures the project according to variables you specify the command line
**NRF5_SDK_PATH**|path to the NRF52 SDK|`-DNRF5_SDK_PATH=/home/jf/nrf52/Pinetime/sdk`|
**CMAKE_BUILD_TYPE (\*)**| Build type (Release or Debug). Release is applied by default if this variable is not specified.|`-DCMAKE_BUILD_TYPE=Debug`
**BUILD_DFU (\*\*)**|Build DFU files while building (needs [adafruit-nrfutil](https://github.com/adafruit/Adafruit_nRF52_nrfutil)).|`-DBUILD_DFU=1`
**BUILD_RESOURCES (\*\*)**| Generate external resource while building (needs [lv_font_conv](https://github.com/lvgl/lv_font_conv) and [lv_img_conv](https://github.com/lvgl/lv_img_conv). |`-DBUILD_RESOURCES=1`
**BUILD_RESOURCES (\*\*)**| Generate external resource while building (needs [lv_font_conv](https://github.com/lvgl/lv_font_conv) and [python3-pil/pillow](https://pillow.readthedocs.io) module). |`-DBUILD_RESOURCES=1`
**TARGET_DEVICE**|Target device, used for hardware configuration. Allowed: `PINETIME, MOY-TFK5, MOY-TIN5, MOY-TON5, MOY-UNK`|`-DTARGET_DEVICE=PINETIME` (Default)
#### (\*) Note about **CMAKE_BUILD_TYPE**

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@ -11,6 +11,7 @@ RUN apt-get update -qq \
make \
python3 \
python3-pip \
python3-pil \
python-is-python3 \
tar \
unzip \
@ -39,10 +40,6 @@ RUN pip3 install -Iv cryptography==3.3
RUN pip3 install cbor
RUN npm i lv_font_conv@1.5.2 -g
RUN npm i ts-node@10.9.1 -g
RUN npm i @swc/core -g
RUN npm i lv_img_conv@0.3.0 -g
# build.sh knows how to compile
COPY build.sh /opt/

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@ -3,8 +3,8 @@ find_program(LV_FONT_CONV "lv_font_conv" NO_CACHE REQUIRED
HINTS "${CMAKE_SOURCE_DIR}/node_modules/.bin")
message(STATUS "Using ${LV_FONT_CONV} to generate font files")
find_program(LV_IMG_CONV "lv_img_conv" NO_CACHE REQUIRED
HINTS "${CMAKE_SOURCE_DIR}/node_modules/.bin")
find_program(LV_IMG_CONV "lv_img_conv.py" NO_CACHE REQUIRED
HINTS "${CMAKE_CURRENT_SOURCE_DIR}")
message(STATUS "Using ${LV_IMG_CONV} to generate font files")
if(CMAKE_VERSION VERSION_GREATER_EQUAL 3.12)

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@ -11,6 +11,9 @@ import subprocess
def gen_lvconv_line(lv_img_conv: str, dest: str, color_format: str, output_format: str, binary_format: str, sources: str):
args = [lv_img_conv, sources, '--force', '--output-file', dest, '--color-format', color_format, '--output-format', output_format, '--binary-format', binary_format]
if lv_img_conv.endswith(".py"):
# lv_img_conv is a python script, call with current python executable
args = [sys.executable] + args
return args

193
src/resources/lv_img_conv.py Executable file
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@ -0,0 +1,193 @@
#!/usr/bin/env python3
import argparse
import pathlib
import sys
import decimal
from PIL import Image
def classify_pixel(value, bits):
def round_half_up(v):
"""python3 implements "propper" "banker's rounding" by rounding to the nearest
even number. Javascript rounds to the nearest integer.
To have the same output as the original JavaScript implementation add a custom
rounding function, which does "school" rounding (to the nearest integer).
see: https://stackoverflow.com/questions/43851273/how-to-round-float-0-5-up-to-1-0-while-still-rounding-0-45-to-0-0-as-the-usual
"""
return int(decimal.Decimal(v).quantize(decimal.Decimal('1'), rounding=decimal.ROUND_HALF_UP))
tmp = 1 << (8 - bits)
val = round_half_up(value / tmp) * tmp
if val < 0:
val = 0
return val
def test_classify_pixel():
# test difference between round() and round_half_up()
assert classify_pixel(18, 5) == 16
# school rounding 4.5 to 5, but banker's rounding 4.5 to 4
assert classify_pixel(18, 6) == 20
def main():
parser = argparse.ArgumentParser()
parser.add_argument("img",
help="Path to image to convert to C header file")
parser.add_argument("-o", "--output-file",
help="output file path (for single-image conversion)",
required=True)
parser.add_argument("-f", "--force",
help="allow overwriting the output file",
action="store_true")
parser.add_argument("-i", "--image-name",
help="name of image structure (not implemented)")
parser.add_argument("-c", "--color-format",
help="color format of image",
default="CF_TRUE_COLOR_ALPHA",
choices=[
"CF_ALPHA_1_BIT", "CF_ALPHA_2_BIT", "CF_ALPHA_4_BIT",
"CF_ALPHA_8_BIT", "CF_INDEXED_1_BIT", "CF_INDEXED_2_BIT", "CF_INDEXED_4_BIT",
"CF_INDEXED_8_BIT", "CF_RAW", "CF_RAW_CHROMA", "CF_RAW_ALPHA",
"CF_TRUE_COLOR", "CF_TRUE_COLOR_ALPHA", "CF_TRUE_COLOR_CHROMA", "CF_RGB565A8",
],
required=True)
parser.add_argument("-t", "--output-format",
help="output format of image",
default="bin", # default in original is 'c'
choices=["c", "bin"])
parser.add_argument("--binary-format",
help="binary color format (needed if output-format is binary)",
default="ARGB8565_RBSWAP",
choices=["ARGB8332", "ARGB8565", "ARGB8565_RBSWAP", "ARGB8888"])
parser.add_argument("-s", "--swap-endian",
help="swap endian of image (not implemented)",
action="store_true")
parser.add_argument("-d", "--dither",
help="enable dither (not implemented)",
action="store_true")
args = parser.parse_args()
img_path = pathlib.Path(args.img)
out = pathlib.Path(args.output_file)
if not img_path.is_file():
print(f"Input file is missing: '{args.img}'")
return 1
print(f"Beginning conversion of {args.img}")
if out.exists():
if args.force:
print(f"overwriting {args.output_file}")
else:
pritn(f"Error: refusing to overwrite {args.output_file} without -f specified.")
return 1
out.touch()
# only implemented the bare minimum, everything else is not implemented
if args.color_format not in ["CF_INDEXED_1_BIT", "CF_TRUE_COLOR_ALPHA"]:
raise NotImplementedError(f"argument --color-format '{args.color_format}' not implemented")
if args.output_format != "bin":
raise NotImplementedError(f"argument --output-format '{args.output_format}' not implemented")
if args.binary_format not in ["ARGB8565_RBSWAP", "ARGB8888"]:
raise NotImplementedError(f"argument --binary-format '{args.binary_format}' not implemented")
if args.image_name:
raise NotImplementedError(f"argument --image-name not implemented")
if args.swap_endian:
raise NotImplementedError(f"argument --swap-endian not implemented")
if args.dither:
raise NotImplementedError(f"argument --dither not implemented")
# open image using Pillow
img = Image.open(img_path)
img_height = img.height
img_width = img.width
if args.color_format == "CF_TRUE_COLOR_ALPHA" and args.binary_format == "ARGB8888":
buf = bytearray(img_height*img_width*4) # 4 bytes (32 bit) per pixel
for y in range(img_height):
for x in range(img_width):
i = (y*img_width + x)*4 # buffer-index
pixel = img.getpixel((x,y))
r, g, b, a = pixel
buf[i + 0] = r
buf[i + 1] = g
buf[i + 2] = b
buf[i + 3] = a
elif args.color_format == "CF_TRUE_COLOR_ALPHA" and args.binary_format == "ARGB8565_RBSWAP":
buf = bytearray(img_height*img_width*3) # 3 bytes (24 bit) per pixel
for y in range(img_height):
for x in range(img_width):
i = (y*img_width + x)*3 # buffer-index
pixel = img.getpixel((x,y))
r_act = classify_pixel(pixel[0], 5)
g_act = classify_pixel(pixel[1], 6)
b_act = classify_pixel(pixel[2], 5)
a = pixel[3]
r_act = min(r_act, 0xF8)
g_act = min(g_act, 0xFC)
b_act = min(b_act, 0xF8)
c16 = ((r_act) << 8) | ((g_act) << 3) | ((b_act) >> 3) # RGR565
buf[i + 0] = (c16 >> 8) & 0xFF
buf[i + 1] = c16 & 0xFF
buf[i + 2] = a
elif args.color_format == "CF_INDEXED_1_BIT": # ignore binary format, use color format as binary format
w = img_width >> 3
if img_width & 0x07:
w+=1
max_p = w * (img_height-1) + ((img_width-1) >> 3) + 8 # +8 for the palette
buf = bytearray(max_p+1)
for y in range(img_height):
for x in range(img_width):
c, a = img.getpixel((x,y))
p = w * y + (x >> 3) + 8 # +8 for the palette
buf[p] |= (c & 0x1) << (7 - (x & 0x7))
# write palette information, for indexed-1-bit we need palette with two values
# write 8 palette bytes
buf[0] = 0
buf[1] = 0
buf[2] = 0
buf[3] = 0
# Normally there is much math behind this, but for the current use case this is close enough
# only needs to be more complicated if we have more than 2 colors in the palette
buf[4] = 255
buf[5] = 255
buf[6] = 255
buf[7] = 255
else:
# raise just to be sure
raise NotImplementedError(f"args.color_format '{args.color_format}' with args.binary_format '{args.binary_format}' not implemented")
# write header
match args.color_format:
case "CF_TRUE_COLOR_ALPHA":
lv_cf = 5
case "CF_INDEXED_1_BIT":
lv_cf = 7
case _:
# raise just to be sure
raise NotImplementedError(f"args.color_format '{args.color_format}' not implemented")
header_32bit = lv_cf | (img_width << 10) | (img_height << 21)
buf_out = bytearray(4 + len(buf))
buf_out[0] = header_32bit & 0xFF
buf_out[1] = (header_32bit & 0xFF00) >> 8
buf_out[2] = (header_32bit & 0xFF0000) >> 16
buf_out[3] = (header_32bit & 0xFF000000) >> 24
buf_out[4:] = buf
# write byte buffer to file
with open(out, "wb") as f:
f.write(buf_out)
return 0
if __name__ == '__main__':
if "--test" in sys.argv:
# run small set of tests and exit
print("running tests")
test_classify_pixel()
print("success!")
sys.exit(0)
# run normal program
sys.exit(main())