# keys: ImageMagick
#    @width                 Width in pixels of output images
#                           Set to -1 to disable width resizing.
#                           Acceptable values: -1 (to disable) or an integer greater than 0 (to enable)
#    @height                Height in pixels of output images
#                           Set to -1 to disable height resizing.
#                           Acceptable values: -1 (to disable) or an integer greater than 0 (to enable)
#    @max_dpi               Maximum supported dpi of output images.
#                           Images with a dpi greater than this value will be downsampled, while images with a lower dpi will not be altered.
#                           Set to -1 to disable dpi alteration.
#                           Note that dpi does not matter when dealing with images on an ereader, so only enable this feature if you plan on printing.
#                           Acceptable values: -1 (to disable) or an integer greater than 0 (to enable)
#    @auto_trim             Determines whether to auto trim the white space around the edges of the manga pages
#                           Acceptable values: true, false
#                           Recommended: true
#    @trim_color            If @auto_trim is enabled, this is the color that should be trimmed.
#                           If you set this value to original, then the trimming algorithm will trim whatever color it encounters first.
#                           Acceptable values: original, white, black, #[hex color code] (for example: #000000)
#                           Recommended: white
#    @trim_fuzz             If @auto_trim is enabled, this is the fuzz value to use when autotrimming.
#                           Acceptable values: An integer between 0 and 100, inclusive
#                           Recommended: 15
#    @trim_cancel           If @auto_trim is enabled, this determines at what percentage of pixel loss should autotrimming be cancelled.
#                           For example, if @trim_cancel is set to 0.6, then autotrimming will be cancelled if 60% of the original pixels would be trimmed away.
#                           Acceptable values: A decimal between 0 and 1.0, inclusive. Set to -1 to disable trim_cancel.
#                           Recommended: 0.7, or -1 (to disable trim cancelling)
#    @add_border            Determines whether to add borders to images smaller than the desired size.
#                           Acceptable values: true, false
#    @add_border_color      If @add_border is enabled, this specifies the color to use for the added border.
#                           Acceptable values: white, black, gray, #[hex color code] (for example: #000000)
#    @auto_rotate           Determines whether to automatically rotate scans to match the specified geometry.
#                           For example, if you set @width to 600 and @height to 800, then landscape scans will be rotated to portrait.
#                           If @width and/or @height is set to -1, then target orientaiton is assumed to be portrait.
#                           Acceptable values: true, false
#                           Recommended: true
#    @color_mode            Type of colors to use for output images.
#                           Acceptable values: grayscale, full
#                           Recommended: grayscale (if using a non-color device), or full (if using a color device)
#    @num_colors            Number of colors to use for output images. The smaller the number, the smaller the file size, but this can also decrease image quality.
#                           Acceptable values: An integer between 8 and 256 inclusive, or -1 to disable color reduction.
#                           Recommended: 256
#    @image_format          Determines whether to force output images to be a certain type, or to just leave the image type unmodified.
#                           Currently, the Kindle DX can handle jpg, gif, png, and bmp.
#                           iPad should support jpg, gif, and tiff.
#                           If your source images are not one of one of these supported types, then you will have to force the image type.
#                           Acceptable values: original, .jpg, .jpeg, .gif, .png, .bmp, .tiff, and pretty much any image format accepted by ImageMagick.
#                           Recommended: .jpg
#                           Note that if you set this value to original, then the converted images will be of the same type as the original images.