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Diffstat (limited to 'packages/noncvs/windows/extra/Gem/dev/plugins/imagesaver.h')
| -rw-r--r-- | packages/noncvs/windows/extra/Gem/dev/plugins/imagesaver.h | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/packages/noncvs/windows/extra/Gem/dev/plugins/imagesaver.h b/packages/noncvs/windows/extra/Gem/dev/plugins/imagesaver.h new file mode 100644 index 00000000..dfb45ae9 --- /dev/null +++ b/packages/noncvs/windows/extra/Gem/dev/plugins/imagesaver.h @@ -0,0 +1,126 @@ +/* ----------------------------------------------------------------- + +GEM - Graphics Environment for Multimedia + +Load an image and return the frame(OS independant interface) + +Copyright (c) 2011-2011 IOhannes m zmölnig. forum::für::umläute. IEM. zmoelnig@iem.at +For information on usage and redistribution, and for a DISCLAIMER OF ALL +WARRANTIES, see the file, "GEM.LICENSE.TERMS" in this distribution. + +-----------------------------------------------------------------*/ + +#ifndef _INCLUDE__GEM_PLUGINS_IMAGESAVER_H_ +#define _INCLUDE__GEM_PLUGINS_IMAGESAVER_H_ + +#include "Gem/Image.h" +#include "Gem/Properties.h" + +#include <string> + + +/*----------------------------------------------------------------- + ------------------------------------------------------------------- + CLASS + imagesaver + + interface for the system- and library-dependent imagesaver classes + + KEYWORDS + save a pix to disk + + DESCRIPTION + + -----------------------------------------------------------------*/ +namespace gem { namespace plugins { + class GEM_EXTERN imagesaver + { + public: + + ////////// + // returns an instance wrapping all plugins or NULL + // if NULL is returned, you might still try your luck with manually accessing the + // PluginFactory + static imagesaver*getInstance(void); + + //////// + // dtor must be virtual + virtual ~imagesaver(void); + + /* save the image 'img' under the filename 'filename', respecting as many 'props' as possible + * + * returns TRUE if saving was successfull, FALSE otherwise */ + virtual bool save(const imageStruct&img, const std::string&filename, const std::string&mimetype, const gem::Properties&props) = 0; + + /* estimate how 'well' we could save the 'img' + * this is used to rate the different backends for a given image + * + * e.g. if the user requests saving of an image as <filename>, virtually all backends will have a way to to as requested + * however, if filename was "bla.jpg", a TIFF-backend might save as a TIFF-image with a .jpg extension, + * which is probably not what the user expected (esp. if there _is_ a JPEG-backend, which for whatever reasons + * would only have been called after the TIFF-backend) + * + * the solution is quite simple: each backend is first asked, how well it could save a given image according to properties + * the backend that returns the highest value, will be chosen first; if it fails to save the image + * (returning FALSE in the save() function), the backend with the next higher rating will be chosen and so on + * + * + * mimetype and properties are the main factors for rating; + * 'mimetype' (string): mimetype of the image; e.g. 'image/jpeg' means 'write the image as JPEG' + * if not empty, the mimetype will override all other ways to set the output format (like filename) + * even though we only expect mimetypes of type 'image/*', the prefix ('image/') is mandatory + * a predefined properties (for legacy reasons) is: + * 'quality' (float) : for lossy formats, this is the quality (in percent) + * + * expected return values: + * <=0: 'USE ME IF YOU MUST (but rather not)' + * 0 is returned, if the backend expects to be able to save the given image under the given + * filename to disk, but it will ignore all properties (including the mimetype!) and will + * ignore all file extensions + * it is hoped that '0' is never the winner (for any feasible format) + * example: saves a TIFF-image as /tmp/foo.doc + * 100: 'YES' + * 100 is returned, if the plugin knows how to handle the given 'mimetype' property + * if 'mimetype' is empty and the plugin has performed an heuristic based on the filename + * to determine that the user wants a format that is provided by this very plugin, it can return 100 as well. + * however, if 'mimetype' and file extension contradict each other, 'mimetype' wins! + * 100+: 'YES, ABSOLUTELY' + * every additional property that can be applied, gains an extra point + * example: both the JPG and the JPEG2K backend provide saving of jpegs, but only JPG can set the quality + * the user requests: filename=img.jpg,mimetype='image/jpeg',quality=20 + * JPG returns 101, whereas JPEG2K returns 100, so JPG wins and writes + * 0..50: the backend knows how to handle some of the properties (but it has no clue about the output format requested + * example: filename=img.tif,mimetype='image/tiff',quality=20 + * JPG knows how to handle the 'quality' property, but not the 'mimetype', so it scores 1 point + * TIFF knows how to handle the 'mimetype' but not the 'quality', so it scores 100 points + */ + virtual float estimateSave( const imageStruct&img, const std::string&filename, const std::string&mimetype, const gem::Properties&props) = 0; + + /** + * get writing capabilities of this backend (informative) + * + * list all (known) mimetypes and properties this backend supports for writing + * both can be empty, if they are not known when requested + * if only some properties/mimetypes are explicitely known (but it is likely that more are supported), + * it is generally better, to list the few rather than nothing + */ + virtual void getWriteCapabilities(std::vector<std::string>&mimetypes, gem::Properties&props) = 0; + + /* returns TRUE, if it is save to use this backend from multple threads + */ + virtual bool isThreadable(void) = 0; + }; + + }; }; // namespace gem + + +/** + * \fn REGISTER_IMAGESAVERFACTORY(const char *id, Class imagesaverClass) + * registers a new class "imagesaverClass" with the imagesaver-factory + * + * \param id a symbolic (const char*) ID for the given class + * \param imagesaverClass a class derived from "imagesaver" + */ +#define REGISTER_IMAGESAVERFACTORY(id, TYP) static gem::PluginFactoryRegistrar::registrar<TYP, gem::plugins::imagesaver> fac_imagesaver_ ## TYP (id) + +#endif // for header file |