OCRmyPDF/tests/test_imageops.py
2023-09-23 15:05:04 -07:00

59 lines
1.7 KiB
Python

# SPDX-FileCopyrightText: 2023 James R. Barlow
# SPDX-License-Identifier: MPL-2.0
from __future__ import annotations
import hypothesis.strategies as st
from hypothesis import given
from PIL import Image
from ocrmypdf.imageops import (
_calculate_downsample,
bytes_per_pixel,
calculate_downsample,
downsample_image,
)
def test_bytes_per_pixel():
assert bytes_per_pixel('RGB') == 4
assert bytes_per_pixel('RGBA') == 4
assert bytes_per_pixel('LA') == 2
assert bytes_per_pixel('L') == 1
def test_calculate_downsample():
im = Image.new('RGB', (100, 100))
assert calculate_downsample(im, max_size=(50, 50)) == (50, 50)
assert calculate_downsample(im, max_pixels=2500) == (50, 50)
assert calculate_downsample(im, max_bytes=10000) == (50, 50)
assert calculate_downsample(im, max_bytes=100000) == (100, 100)
@given(
st.one_of(st.just("RGB"), st.just('L')),
st.integers(min_value=1, max_value=100000),
st.integers(min_value=1, max_value=100000),
st.integers(min_value=64, max_value=100000),
st.integers(min_value=64, max_value=100000),
st.integers(min_value=64 * 64, max_value=1000000),
)
def test_calculate_downsample_hypothesis(mode, im_w, im_h, max_x, max_y, max_bytes):
result = _calculate_downsample(
(im_w, im_h),
bytes_per_pixel(mode),
max_size=(max_x, max_y),
max_bytes=max_bytes,
)
assert result[0] <= max_x
assert result[1] <= max_y
assert result[0] * result[1] * bytes_per_pixel(mode) <= max_bytes
def test_downsample_image():
im = Image.new('RGB', (100, 100))
im.info['dpi'] = (300, 300)
ds = downsample_image(im, (50, 50))
assert ds.size == (50, 50)
assert ds.info['dpi'] == (150, 150)