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JPEGGenerator.h Go to the documentation of this file. //-*-c++-*- #ifndef INCLUDED_JPEGGenerator_h_ #define INCLUDED_JPEGGenerator_h_ #include "Vision/FilterBankGenerator.h" extern "C" { #include <jpeglib.h> } //! Generates FilterBankEvents containing JPEG compressed images /*! There's only one channel per resolution layer, which holds the * compressed data. This is mostly intended for being sent over * wireless, but if you know how JPEG works, you may be able to * interpret the compressed data directly and glean useful * information from it. After all, compression is all about throwing * away unimportant details and storing the salient information. * * The generated events use 0 for their event source IDs. The row * skip and row stride are 0. (they don't really apply here) * * This can either compress a greyscale image or an interleaved YUV * image. If the source generator's type is not * InterleavedYUVGenerator, it will assume greyscale. Call * setSource() to override this. * * The InterleavedYUVGenerator is separated from this because it * wouldn't really make things much faster to combine the algorithms, * and others might find the interleaved format handy for passing to * other libraries which expect that format, such as what happened * with libjpeg. * * This class shares a lot of non-JPEG specific code with PNGGenerator, * so you may want to replicate any changes made in that class as well. * * @todo possible speedup by using jpeg_write_raw_data * @todo create a common super class with PNGGenerator to hold common setup code */ class JPEGGenerator : public FilterBankGenerator { public: static const unsigned int JPEG_HEADER_PAD=500; //!< add a bit to the expected size in getBinSize just to leave a little extra room for small images //! defines how to interpret the source images (see #srcMode and #curMode) enum src_mode_t { SRC_AUTO, //!< if src is not a InterleavedYUVGenerator, SRC_GREYSCALE, otherwise SRC_COLOR SRC_GRAYSCALE, //!< indicates each channel of source should be compressed individually as grayscale images SRC_COLOR //!< indicates first channel should be in an interleaved layout which can be compressed into a "color" image }; //! constructor JPEGGenerator(unsigned int mysid, FilterBankGenerator* fbg, EventBase::EventTypeID_t tid); //! constructor JPEGGenerator(unsigned int mysid, JPEGGenerator::src_mode_t sMode, FilterBankGenerator* fbg, EventBase::EventTypeID_t tid); //! destructor virtual ~JPEGGenerator(); //! set #srcMode and #curMode as well if @a mode==SRC_AUTO virtual void setSourceMode(src_mode_t mode) { srcMode=mode; if(mode!=SRC_AUTO) curMode=mode;} //! returns #srcMode virtual src_mode_t getSourceMode() const { return srcMode; } //! returns #curMode virtual src_mode_t getCurrentSourceFormat() const { return curMode; } static std::string getClassDescription() { return "Compresses its source FilterBankGenerator's data into JPEG format"; } //! should receive FilterBankEvents from a RawCameraGenerator (or a subclass thereof) virtual void processEvent(const EventBase& event); //! if we don't already know bytesUsed, let's assume the size will be smaller than the original uncompressed. If we fail this assumption, probably better to fail anyway. virtual unsigned int getBinSize() const; virtual unsigned int loadBuffer(const char buf[], unsigned int len); //! you probably don't want to be calling this to access the JPEG -- use getImage() instead (saveBuffer will prepend some header information before the actual image data) virtual unsigned int saveBuffer(char buf[], unsigned int len) const; //! returns #quality virtual unsigned int getQuality() const { return quality; } //! sets #quality; this will invalidate the cache if @a q does not equal current #quality virtual void setQuality(unsigned int q) { if(quality!=q) { quality=q; invalidateCaches(); } } //! returns the number of bytes used for the image returned by getImage() - will return 0 if the image hasn't been calculated yet (so call it @e after getImage()) virtual unsigned int getImageSize(unsigned int layer, unsigned int chan) const { return bytesUsed[layer][chan]; } protected: virtual void setNumImages(unsigned int nLayers, unsigned int nChannels); virtual unsigned char * createImageCache(unsigned int layer, unsigned int chan) const; virtual void calcImage(unsigned int layer, unsigned int chan); virtual void destruct(); src_mode_t srcMode; //!< how to interpret source channel of next filter bank event src_mode_t curMode; //!< how to interpret getImage's current image unsigned int ** bytesUsed; //!< number of bytes used per image to actually store data; struct jpeg_compress_struct cinfo; //!< used to interface with libjpeg - holds compression parameters and state struct jpeg_error_mgr jerr; //!< used to interface with libjpeg - gives us access to error information unsigned int quality; //!< quality level to pass to libjpeg; -1U causes Config::vision_config::rawcam_compress_quality to be used private: JPEGGenerator(const JPEGGenerator& fbk); //!< don't call const JPEGGenerator& operator=(const JPEGGenerator& fbk); //!< don't call }; /*! @file * @brief Describes JPEGGenerator, which generates FilterBankEvents containing JPEG compressed images * @author ejt (Creator) * * $Author: ejt $ * $Name: tekkotsu-3_0 $ * $Revision: 1.13 $ * $State: Exp $ * $Date: 2006/09/16 17:32:40 $ */ #endif

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