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Added python only converter backend supporting resizing, zooming and rotation

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This commit is contained in:
Roberto Rosario
2011-07-16 04:03:17 -04:00
parent 7a5f0fed0b
commit 7289cafdfd
5 changed files with 45 additions and 73 deletions
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24
apps/converter/backends/__init__.py
View File

@@ -2,13 +2,6 @@ class ConverterBase(object):
"""
Base class that all backend classes must inherit
"""
def identify_file(self, input_filepath, *args, **kwargs):
raise NotImplementedError("Your %s class has not defined a identify_file() method, which is required." % self.__class__.__name__)
def identify_document(self, document, *args, **kwargs):
raise NotImplementedError("Your %s class has not defined a identify_document() method, which is required." % self.__class__.__name__)
def convert_file(self, input_filepath, *args, **kwargs):
raise NotImplementedError("Your %s class has not defined a convert_file() method, which is required." % self.__class__.__name__)
@@ -21,22 +14,5 @@ class ConverterBase(object):
def get_available_transformations(self):
raise NotImplementedError("Your %s class has not defined a get_available_transformations() method, which is required." % self.__class__.__name__)
def get_transformation_string(self, transformation_list):
transformations = []
warnings = []
transformation_choices = self.get_available_transformations()
for transformation in transformation_list:
try:
if transformation['transformation'] in transformation_choices:
transformations.append(
transformation_choices[transformation['transformation']]['command_line'] % eval(
transformation['arguments']
)
)
except Exception, e:
warnings.append(e)
return u' '.join(transformations), warnings
def get_page_count(self):
raise NotImplementedError("Your %s class has not defined a get_page_count() method, which is required." % self.__class__.__name__)

5
apps/converter/backends/graphicsmagick/base.py
View File

@@ -4,7 +4,8 @@ import re
from converter.conf.settings import GM_PATH
from converter.conf.settings import GM_SETTINGS
from converter.literals import QUALITY_DEFAULT, QUALITY_SETTINGS
from converter.exceptions import ConvertError, UnknownFormat, IdentifyError
from converter.exceptions import ConvertError, UnknownFormat, \
IdentifyError
from converter.backends import ConverterBase
from converter.literals import TRANSFORMATION_RESIZE, \
TRANSFORMATION_ROTATE, TRANSFORMATION_DENSITY, \
@@ -50,7 +51,7 @@ class ConverterClass(ConverterBase):
arguments.append(u'-rotate')
arguments.append(u'%s' % transformation['arguments']['degrees'])
if format == u'jpg':
if format == u'jpeg':
arguments.append(u'-quality')
arguments.append(u'85')

7
apps/converter/backends/imagemagick/base.py
View File

@@ -1,8 +1,6 @@
import subprocess
import re
from django.utils.translation import ugettext_lazy as _
from converter.conf.settings import IM_IDENTIFY_PATH
from converter.conf.settings import IM_CONVERT_PATH
from converter.api import QUALITY_DEFAULT, QUALITY_SETTINGS
@@ -12,6 +10,8 @@ from converter.backends import ConverterBase
from converter.literals import TRANSFORMATION_RESIZE, \
TRANSFORMATION_ROTATE, TRANSFORMATION_DENSITY, \
TRANSFORMATION_ZOOM
from converter.literals import DIMENSION_SEPARATOR, DEFAULT_PAGE_NUMBER, \
DEFAULT_FILE_FORMAT
CONVERTER_ERROR_STRING_NO_DECODER = u'no decode delegate for this image format'
@@ -30,7 +30,6 @@ class ConverterClass(ConverterBase):
raise IdentifyError(proc.stderr.readline())
return proc.stdout.read()
def convert_file(self, input_filepath, output_filepath, quality=QUALITY_DEFAULT, page=DEFAULT_PAGE_NUMBER, file_format=DEFAULT_FILE_FORMAT):
arguments = []
if transformations:
@@ -51,7 +50,7 @@ class ConverterClass(ConverterBase):
arguments.append(u'-rotate')
arguments.append(u'%s' % transformation['arguments']['degrees'])
if format == u'jpg':
if format == u'jpeg':
arguments.append(u'-quality')
arguments.append(u'85')

74
apps/converter/backends/python/base.py
View File

@@ -6,13 +6,11 @@ from converter.literals import QUALITY_DEFAULT, QUALITY_SETTINGS
from converter.exceptions import ConvertError, UnknownFormat, IdentifyError
from converter.backends import ConverterBase
from converter.literals import TRANSFORMATION_RESIZE, \
TRANSFORMATION_ROTATE
TRANSFORMATION_ROTATE, TRANSFORMATION_ZOOM
from converter.literals import QUALITY_DEFAULT, DEFAULT_PAGE_NUMBER, \
DEFAULT_FILE_FORMAT
class ConverterClass(ConverterBase):
def identify_file(self, input_filepath, arguments=None):
pass
def get_page_count(self, input_filepath):
page_count = 1
im = Image.open(input_filepath)
@@ -27,32 +25,38 @@ class ConverterClass(ConverterBase):
return page_count
def convert_file(self, input_filepath, output_filepath, quality=QUALITY_DEFAULT, arguments=None):
def convert_file(self, input_filepath, output_filepath, transformations=None, quality=QUALITY_DEFAULT, page=DEFAULT_PAGE_NUMBER, file_format=DEFAULT_FILE_FORMAT):
try:
im = Image.open(input_filepath)
outfile, format = output_filepath.split(u':')
im.save(outfile, format)
'''
command = []
command.append(unicode(GM_PATH))
command.append(u'convert')
command.extend(unicode(QUALITY_SETTINGS[quality]).split())
command.extend(unicode(GM_SETTINGS).split())
command.append(unicode(input_filepath))
if arguments:
command.extend(unicode(arguments).split())
command.append(unicode(output_filepath))
proc = subprocess.Popen(command, close_fds=True, stderr=subprocess.PIPE, stdout=subprocess.PIPE)
return_code = proc.wait()
if return_code != 0:
#Got an error from convert program
error_line = proc.stderr.readline()
if (CONVERTER_ERROR_STRING_NO_DECODER in error_line) or (CONVERTER_ERROR_STARTS_WITH in error_line):
#Try to determine from error message which class of error is it
except Exception: # Python Imaging Library doesn't recognize it as an image
raise UnknownFormat
else:
raise ConvertError(error_line)
'''
current_page = 0
try:
while current_page == page - 1:
im.seek(im.tell() + 1)
current_page += 1
# do something to im
except EOFError:
pass # end of sequence
if transformations:
for transformation in transformations:
aspect = 1.0 * im.size[1] / im.size[0]
if transformation['transformation'] == TRANSFORMATION_RESIZE:
width = int(transformation['arguments']['width'])
height = int(transformation['arguments'].get('height', 1.0 * width * aspect))
im = im.resize((width, height), Image.ANTIALIAS)
elif transformation['transformation'] == TRANSFORMATION_ZOOM:
decimal_value = float(transformation['arguments']['percent']) / 100
im = im.transform((im.size[0] * decimal_value, im.size[1] * decimal_value), Image.EXTENT, (0, 0, im.size[0], im.size[1]))
elif transformation['transformation'] == TRANSFORMATION_ROTATE:
# PIL counter degress counter-clockwise, reverse them
im = im.rotate(360 - transformation['arguments']['degrees'])
if im.mode not in ('L', 'RGB'):
im = im.convert('RGB')
im.save(output_filepath, format=file_format)
def get_format_list(self):
"""
@@ -65,16 +69,8 @@ class ConverterClass(ConverterBase):
return formats
def get_available_transformations(self):
return [
TRANSFORMATION_RESIZE, TRANSFORMATION_ROTATE
TRANSFORMATION_RESIZE, TRANSFORMATION_ROTATE, \
TRANSFORMATION_ZOOM
]
def get_page_count(self, input_filepath):
try:
return len(self.identify_file(unicode(input_filepath)).splitlines())
except:
#TODO: send to other page number identifying program
return 1

2
apps/converter/literals.py
View File

@@ -8,7 +8,7 @@ from converter.conf.settings import PRINT_QUALITY_OPTIONS
DEFAULT_ZOOM_LEVEL = 100
DEFAULT_ROTATION = 0
DEFAULT_PAGE_NUMBER = 1
DEFAULT_FILE_FORMAT = u'jpg'
DEFAULT_FILE_FORMAT = u'jpeg'
DEFAULT_OCR_FILE_FORMAT = u'tif'
QUALITY_DEFAULT = u'quality_default'