Minecraft-Overviewer/overviewer_core/optimizeimages.py

#    This file is part of the Minecraft Overviewer.
#
#    Minecraft Overviewer is free software: you can redistribute it and/or
#    modify it under the terms of the GNU General Public License as published
#    by the Free Software Foundation, either version 3 of the License, or (at
#    your option) any later version.
#
#    Minecraft Overviewer is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
#    Public License for more details.
#
#    You should have received a copy of the GNU General Public License along
#    with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.

import os
import subprocess
import shlex
import logging

class Optimizer:
    binaryname = ""

    def __init__(self):
        raise NotImplementedError("I can't let you do that, Dave.")

    def optimize(self, img):
        raise NotImplementedError("I can't let you do that, Dave.")
    
    def fire_and_forget(self, args):
        subprocess.check_call(args)

    def check_availability(self):
        path = os.environ.get("PATH").split(os.pathsep)
        
        def exists_in_path(prog):
            result = filter(lambda x: os.path.exists(os.path.join(x, prog)), path)
            return len(result) != 0

        if (not exists_in_path(self.binaryname)) and (not exists_in_path(self.binaryname + ".exe")):
            raise Exception("Optimization program '%s' was not found!" % self.binaryname)
    
    def is_crusher(self):
        """Should return True if the optimization is lossless, i.e. none of the actual image data will be changed."""
        raise NotImplementedError("I'm so abstract I can't even say whether I'm a crusher.")
        

class NonAtomicOptimizer(Optimizer):
    def cleanup(self, img):
        os.remove(img)
        os.rename(img + ".tmp", img)

    def fire_and_forget(self, args, img):
        subprocess.check_call(args)
        self.cleanup(img)

class PNGOptimizer:
    def __init__(self):
        raise NotImplementedError("I can't let you do that, Dave.")

class JPEGOptimizer:
    def __init__(self):
        raise NotImplementedError("I can't let you do that, Dave.")

class pngnq(NonAtomicOptimizer, PNGOptimizer):
    binaryname = "pngnq"

    def __init__(self, sampling=3, dither="n"):
        if sampling < 1 or sampling > 10:
            raise Exception("Invalid sampling value '%d' for pngnq!" % sampling)

        if dither not in ["n", "f"]:
            raise Exception("Invalid dither method '%s' for pngnq!" % dither)

        self.sampling = sampling
        self.dither = dither
    
    def optimize(self, img):
        if img.endswith(".tmp"):
            extension = ".tmp"
        else:
            extension = ".png.tmp"

        args = [self.binaryname, "-s", str(self.sampling), "-f", "-e", extension, img]
        # Workaround for poopbuntu 12.04 which ships an old broken pngnq
        if self.dither != "n":
            args.insert(1, "-Q")
            args.insert(2, self.dither)

        NonAtomicOptimizer.fire_and_forget(self, args, img)

    def is_crusher(self):
        return False

class pngcrush(NonAtomicOptimizer, PNGOptimizer):
    binaryname = "pngcrush"
    # really can't be bothered to add some interface for all
    # the pngcrush options, it sucks anyway
    def __init__(self, brute=False):
        self.brute = brute
        
    def optimize(self, img):
        args = [self.binaryname, img, img + ".tmp"]
        if self.brute == True:  # Was the user an idiot?
            args.insert(1, "-brute")

        NonAtomicOptimizer.fire_and_forget(self, args, img)

    def is_crusher(self):
        return True

class optipng(Optimizer, PNGOptimizer):
    binaryname = "optipng"

    def __init__(self, olevel=2):
        self.olevel = olevel
    
    def optimize(self, img):
        Optimizer.fire_and_forget(self, [self.binaryname, "-o" + str(self.olevel), "-quiet", img])

    def is_crusher(self):
        return True

class jpegoptim(Optimizer, JPEGOptimizer):
    binaryname = "jpegoptim"
    crusher = True
    quality = None
    target_size = None

    def __init__(self, quality = None, target_size = None):
        if quality is not None:
            if quality < 0 or quality > 100:
                raise Exception("Invalid target quality %d for jpegoptim" % quality)
            self.quality = quality

        if target_size is not None:
            self.target_size = target_size

    def optimize(self, img):
        args = [self.binaryname, "-q", "-p"]
        if self.quality is not None:
            args.append("-m" + str(self.quality))

        if self.target_size is not None:
            args.append("-S" + str(self.target_size))

        args.append(img)

        Optimizer.fire_and_forget(self, args)

    def is_crusher(self):
        # Technically, optimisation is lossless if input image quality
        # is below target quality, but this is irrelevant in this case
        if (self.quality is not None) or (self.target_size is not None):
            return False
        else:
            return True

        

def optimize_image(imgpath, imgformat, optimizers):
        for opt in optimizers:
            if imgformat == 'png':
                if isinstance(opt, PNGOptimizer):
                    opt.optimize(imgpath)
            elif imgformat == 'jpg':
                if isinstance(opt, JPEGOptimizer):
                    opt.optimize(imgpath)