+ Gets a user-defined integer-valued option.
+
+ The function is case-insensitive to @a name.
+ If the given option is not present, the function returns 0.
+ Use HasOption() is 0 is a possibly valid value for the option.
+
+ Generic options:
+ @li @c wxIMAGE_OPTION_MAX_WIDTH and @c wxIMAGE_OPTION_MAX_HEIGHT: If either
+ of these options is specified, the loaded image will be scaled down
+ (preserving its aspect ratio) so that its width is less than the
+ max width given if it is not 0 @em and its height is less than the
+ max height given if it is not 0. This is typically used for loading
+ thumbnails and the advantage of using these options compared to
+ calling Rescale() after loading is that some handlers (only JPEG
+ one right now) support rescaling the image during loading which is
+ vastly more efficient than loading the entire huge image and
+ rescaling it later (if these options are not supported by the
+ handler, this is still what happens however). These options must be
+ set before calling LoadFile() to have any effect.
+
+ @li @c wxIMAGE_OPTION_QUALITY: JPEG quality used when saving. This is an
+ integer in 0..100 range with 0 meaning very poor and 100 excellent
+ (but very badly compressed). This option is currently ignored for
+ the other formats.
+
+ @li @c wxIMAGE_OPTION_RESOLUTIONUNIT: The value of this option determines
+ whether the resolution of the image is specified in centimetres or
+ inches, see wxImageResolution enum elements.
+
+ @li @c wxIMAGE_OPTION_RESOLUTION, @c wxIMAGE_OPTION_RESOLUTIONX and
+ @c wxIMAGE_OPTION_RESOLUTIONY: These options define the resolution of
+ the image in the units corresponding to @c wxIMAGE_OPTION_RESOLUTIONUNIT
+ options value. The first option can be set before saving the image
+ to set both horizontal and vertical resolution to the same value.
+ The X and Y options are set by the image handlers if they support
+ the image resolution (currently BMP, JPEG and TIFF handlers do) and
+ the image provides the resolution information and can be queried
+ after loading the image.
+
+ Options specific to wxPNGHandler:
+ @li @c wxIMAGE_OPTION_PNG_FORMAT: Format for saving a PNG file, see
+ wxImagePNGType for the supported values.
+ @li @c wxIMAGE_OPTION_PNG_BITDEPTH: Bit depth for every channel (R/G/B/A).
+ @li @c wxIMAGE_OPTION_PNG_FILTER: Filter for saving a PNG file, see libpng
+ (http://www.libpng.org/pub/png/libpng-1.2.5-manual.html) for possible values
+ (e.g. PNG_FILTER_NONE, PNG_FILTER_SUB, PNG_FILTER_UP, etc).
+ @li @c wxIMAGE_OPTION_PNG_COMPRESSION_LEVEL: Compression level (0..9) for
+ saving a PNG file. An high value creates smaller-but-slower PNG file.
+ Note that unlike other formats (e.g. JPEG) the PNG format is always
+ lossless and thus this compression level doesn't tradeoff the image
+ quality.
+ @li @c wxIMAGE_OPTION_PNG_COMPRESSION_MEM_LEVEL: Compression memory usage
+ level (1..9) for saving a PNG file. An high value means the saving
+ process consumes more memory, but may create smaller PNG file.
+ @li @c wxIMAGE_OPTION_PNG_COMPRESSION_STRATEGY: Possible values are 0 for
+ default strategy, 1 for filter, and 2 for Huffman-only.
+ You can use OptiPNG (http://optipng.sourceforge.net/) to get a suitable
+ value for your application.
+ @li @c wxIMAGE_OPTION_PNG_COMPRESSION_BUFFER_SIZE: Internal buffer size
+ (in bytes) for saving a PNG file. Ideally this should be as big as
+ the resulting PNG file. Use this option if your application produces
+ images with small size variation.
+
+ @param name
+ The name of the option, case-insensitive.
+ @return
+ The value of the option or 0 if not found.
+ Use HasOption() if 0 can be a valid option value.
+
+ @see SetOption(), GetOption()