def do_optimization(t: Task) -> TaskResult:
""" Try to reduce file size of an image.
Expects a Task object containing all the parameters for the image processing.
The actual processing is done by the corresponding function,
according to the detected image format.
:param t: A Task object containing all the parameters for the image processing.
:return: A TaskResult object containing information for single file report.
"""
# TODO: Catch exceptions that may occur here.
try:
img = Image.open(t.src_path)
# TODO: improve method of image format detection (what should happen if the
# file extension does not match the image content's format? Maybe we
# should skip unsupported formats?)
if img.format.upper() == 'PNG':
return optimize_png(t)
elif img.format.upper() in ('JPEG', 'MPO'):
return optimize_jpg(t)
else:
try:
had_exif = True if piexif.load(t.src_path)['Exif'] else False
except piexif.InvalidImageDataError: # Not a supported format
had_exif = False
except ValueError: # No exif info
had_exif = False
return TaskResult(img=t.src_path,
orig_format=img.format.upper(),
result_format=img.format.upper(),
orig_mode=img.mode,
result_mode=img.mode,
orig_colors=0,
final_colors=0,
orig_size=os.path.getsize(t.src_path),
final_size=0,
was_optimized=False,
was_downsized=False,
had_exif=had_exif,
has_exif=had_exif)
except IOError:
try:
had_exif = True if piexif.load(t.src_path)['Exif'] else False
except piexif.InvalidImageDataError: # Not a supported format
had_exif = False
except ValueError: # No exif info
had_exif = False
return TaskResult(img=t.src_path,
orig_format="",
result_format="",
orig_mode="",
result_mode="",
orig_colors=0,
final_colors=0,
orig_size=os.path.getsize(t.src_path),
final_size=0,
was_optimized=False,
was_downsized=False,
had_exif=had_exif,
has_exif=had_exif)
def optimize_png(t: Task) -> TaskResult:
""" Try to reduce file size of a PNG image.
Expects a Task object containing all the parameters for the image processing.
If file reduction is successful, this function will replace the original
file with the optimized version and return some report data (file path,
image format, image color mode, original file size, resulting file size,
and resulting status of the optimization.
:param t: A Task object containing all the parameters for the image processing.
:return: A TaskResult object containing information for single file report.
"""
img = Image.open(t.src_path)
orig_format = img.format
orig_mode = img.mode
folder, filename = os.path.split(t.src_path)
temp_file_path = os.path.join(folder + "/~temp~" + filename)
orig_size = os.path.getsize(t.src_path)
orig_colors, final_colors = 0, 0
had_exif = has_exif = False # Currently no exif methods for PNG files
if orig_mode == 'P':
final_colors = orig_colors = len(img.getcolors())
if t.convert_all or (t.conv_big and is_big_png_photo(t.src_path)):
# convert to jpg format
filename = os.path.splitext(os.path.basename(t.src_path))[0]
conv_file_path = os.path.join(folder + "/" + filename + ".jpg")
if t.max_w or t.max_h:
img, was_downsized = downsize_img(img, t.max_w, t.max_h)
else:
was_downsized = False
img = remove_transparency(img, t.bg_color)
img = img.convert("RGB")
if t.grayscale:
img = make_grayscale(img)
try:
img.save(conv_file_path,
quality=t.quality,
optimize=True,
progressive=True,
format="JPEG")
except IOError:
ImageFile.MAXBLOCK = img.size[0] * img.size[1]
img.save(conv_file_path,
quality=t.quality,
optimize=True,
progressive=True,
format="JPEG")
# Only save the converted file if conversion did save any space
final_size = os.path.getsize(conv_file_path)
if t.no_size_comparison or (orig_size - final_size > 0):
was_optimized = True
if t.force_del:
try:
os.remove(t.src_path)
except OSError as e:
msg = "Error while replacing original PNG with the " \
"new JPEG version."
print(f"\n{msg}\n{e}\n")
else:
final_size = orig_size
was_optimized = False
try:
os.remove(conv_file_path)
except OSError as e:
msg = "Error while removing temporary JPEG converted file."
print(f"\n{msg}\n{e}\n")
result_format = "JPEG"
return TaskResult(t.src_path, orig_format, result_format, orig_mode,
img.mode, orig_colors, final_colors, orig_size,
final_size, was_optimized, was_downsized, had_exif,
has_exif)
# if PNG and user didn't ask for PNG to JPEG conversion, do this instead.
else:
result_format = "PNG"
if t.remove_transparency:
img = remove_transparency(img, t.bg_color)
if t.max_w or t.max_h:
img, was_downsized = downsize_img(img, t.max_w, t.max_h)
else:
was_downsized = False
if t.reduce_colors:
img, orig_colors, final_colors = do_reduce_colors(
img, t.max_colors)
if t.grayscale:
img = make_grayscale(img)
if not t.fast_mode and img.mode == "P":
img, final_colors = rebuild_palette(img)
try:
img.save(temp_file_path, optimize=True, format=result_format)
except IOError:
ImageFile.MAXBLOCK = img.size[0] * img.size[1]
img.save(temp_file_path, optimize=True, format=result_format)
final_size = os.path.getsize(temp_file_path)
# Only replace the original file if compression did save any space
if t.no_size_comparison or (orig_size - final_size > 0):
shutil.move(temp_file_path, os.path.expanduser(t.src_path))
was_optimized = True
else:
final_size = orig_size
was_optimized = False
try:
os.remove(temp_file_path)
except OSError as e:
print(f"\nError while removing temporary file.\n{e}\n")
return TaskResult(t.src_path, orig_format, result_format, orig_mode,
img.mode, orig_colors, final_colors, orig_size,
final_size, was_optimized, was_downsized, had_exif,
has_exif)
def optimize_jpg(t: Task) -> TaskResult:
""" Try to reduce file size of a JPG image.
Expects a Task object containing all the parameters for the image processing.
If file reduction is successful, this function will replace the original
file with the optimized version and return some report data (file path,
image format, image color mode, original file size, resulting file size,
and resulting status of the optimization.
:param t: A Task object containing all the parameters for the image processing.
:return: A TaskResult object containing information for single file report.
"""
img = Image.open(t.src_path)
orig_format = img.format
orig_mode = img.mode
folder, filename = os.path.split(t.src_path)
if folder == '':
folder = os.getcwd()
temp_file_path = os.path.join(folder + "/~temp~" + filename)
orig_size = os.path.getsize(t.src_path)
orig_colors, final_colors = 0, 0
result_format = "JPEG"
try:
had_exif = True if piexif.load(t.src_path)['Exif'] else False
except piexif.InvalidImageDataError: # Not a supported format
had_exif = False
except ValueError: # No exif info
had_exif = False
# TODO: Check if we can provide a more specific treatment of piexif exceptions.
except Exception:
had_exif = False
if t.max_w or t.max_h:
img, was_downsized = downsize_img(img, t.max_w, t.max_h)
else:
was_downsized = False
if t.grayscale:
img = make_grayscale(img)
# only use progressive if file size is bigger
use_progressive_jpg = orig_size > 10000
if t.fast_mode:
quality = t.quality
else:
quality, jpgdiff = jpeg_dynamic_quality(img)
try:
img.save(temp_file_path,
quality=quality,
optimize=True,
progressive=use_progressive_jpg,
format=result_format)
except IOError:
ImageFile.MAXBLOCK = img.size[0] * img.size[1]
img.save(temp_file_path,
quality=quality,
optimize=True,
progressive=use_progressive_jpg,
format=result_format)
if t.keep_exif and had_exif:
try:
piexif.transplant(os.path.expanduser(t.src_path), temp_file_path)
has_exif = True
except ValueError:
has_exif = False
# TODO: Check if we can provide a more specific treatment of piexif exceptions.
except Exception:
had_exif = False
else:
has_exif = False
# Only replace the original file if compression did save any space
final_size = os.path.getsize(temp_file_path)
if t.no_size_comparison or (orig_size - final_size > 0):
shutil.move(temp_file_path, os.path.expanduser(t.src_path))
was_optimized = True
else:
final_size = orig_size
was_optimized = False
try:
os.remove(temp_file_path)
except OSError as e:
details = 'Error while removing temporary file.'
show_img_exception(e, t.src_path, details)
return TaskResult(t.src_path, orig_format, result_format, orig_mode,
img.mode, orig_colors, final_colors, orig_size,
final_size, was_optimized, was_downsized, had_exif,
has_exif)
def optimize_png(task: Task) -> TaskResult:
""" Try to reduce file size of a PNG image.
Expects a Task object containing all the parameters for the image processing.
If file reduction is successful, this function will replace the original
file with the optimized version and return some report data (file path,
image format, image color mode, original file size, resulting file size,
and resulting status of the optimization.
:param task: A Task object containing all the parameters for the image processing.
:return: A TaskResult object containing information for single file report.
"""
img: Image.Image = Image.open(task.src_path)
orig_format = img.format
orig_mode = img.mode
folder, filename = os.path.split(task.src_path)
if folder == '':
folder = os.getcwd()
orig_size = os.path.getsize(task.src_path)
orig_colors, final_colors = 0, 0
had_exif = has_exif = False # Currently no exif methods for PNG files
if orig_mode == 'P':
final_colors = orig_colors = len(img.getcolors())
if task.convert_all or (task.conv_big and is_big_png_photo(task.src_path)):
# convert to jpg format
filename = os.path.splitext(os.path.basename(task.src_path))[0]
output_path = os.path.join(folder + "/" + filename + ".jpg")
if task.max_w or task.max_h:
img, was_downsized = downsize_img(img, task.max_w, task.max_h)
else:
was_downsized = False
img = remove_transparency(img, task.bg_color)
img = img.convert("RGB")
if task.grayscale:
img = make_grayscale(img)
tmp_buffer = BytesIO() # In-memory buffer
try:
img.save(
tmp_buffer,
quality=task.quality,
optimize=True,
progressive=True,
format="JPEG")
except IOError:
ImageFile.MAXBLOCK = img.size[0] * img.size[1]
img.save(
tmp_buffer,
quality=task.quality,
optimize=True,
progressive=True,
format="JPEG")
img_mode = img.mode
img.close()
compare_sizes = not (task.no_size_comparison or task.convert_all)
was_optimized, final_size = save_compressed(task.src_path,
tmp_buffer,
force_delete=task.force_del,
compare_sizes=compare_sizes,
output_path=output_path)
result_format = "JPEG"
return TaskResult(task.src_path, orig_format, result_format,
orig_mode, img_mode, orig_colors, final_colors,
orig_size, final_size, was_optimized,
was_downsized, had_exif, has_exif)
# if PNG and user didn't ask for PNG to JPEG conversion, do this instead.
else:
result_format = "PNG"
if task.remove_transparency:
img = remove_transparency(img, task.bg_color)
if task.max_w or task.max_h:
img, was_downsized = downsize_img(img, task.max_w, task.max_h)
else:
was_downsized = False
if task.reduce_colors:
img, orig_colors, final_colors = do_reduce_colors(
img, task.max_colors)
if task.grayscale:
img = make_grayscale(img)
if not task.fast_mode and img.mode == "P":
img, final_colors = rebuild_palette(img)
tmp_buffer = BytesIO() # In-memory buffer
try:
img.save(tmp_buffer, optimize=True, format=result_format)
except IOError:
ImageFile.MAXBLOCK = img.size[0] * img.size[1]
img.save(tmp_buffer, optimize=True, format=result_format)
img_mode = img.mode
img.close()
compare_sizes = not task.no_size_comparison
was_optimized, final_size = save_compressed(task.src_path,
tmp_buffer,
force_delete=task.force_del,
compare_sizes=compare_sizes)
return TaskResult(task.src_path, orig_format, result_format, orig_mode,
img_mode, orig_colors, final_colors, orig_size,
final_size, was_optimized, was_downsized, had_exif,
has_exif)