ImageNpy.h

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/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */
 
#ifndef META_OCEAN_MEDIA_SPECIAL_IMAGE_NPY_H
#define META_OCEAN_MEDIA_SPECIAL_IMAGE_NPY_H
 
#include "ocean/media/special/Special.h"
 
#include "ocean/base/Frame.h"
 
namespace Ocean
{
 
namespace Media
{
 
namespace Special
{
 
/**
 * This class implements read and write functions for NPY (NumPy) images.
 * @ingroup mediaoil
 */
class OCEAN_MEDIA_SPECIAL_EXPORT ImageNpy
{
    public:
 
        /**
         * Decodes a NPY image from a given binary buffer.
         * @param buffer The buffer from which the image will be loaded, must be valid
         * @param size The size of the given buffer in bytes, with range [1, infinity)
         * @return The frame containing the image information, an invalid frame if the image could not be loaded
         */
        static Frame decodeImage(const void* buffer, const size_t size);
 
        /**
         * Encodes a given frame as NPY image to a resulting buffer.
         * @param frame The frame to be written, must be valid
         * @param buffer The resulting buffer storing the binary information of the NPY image
         * @return True, if succeeded
         */
        static bool encodeImage(const Frame& frame, std::vector<uint8_t>& buffer);
 
        /**
         * Returns whether a given pixel format is supported natively.
         * @param pixelFormat The pixel format to be checked
         * @return True, if so; False, if a conversion will be necessary
         */
        static inline bool isPixelFormatSupported(const FrameType::PixelFormat pixelFormat);
 
        /**
         * Returns whether a given pixel origin is supported natively.
         * @param pixelOrigin The pixel origin to be checked
         * @return True, if so; False, if a conversion will be necessary
         */
        static inline bool isPixelOriginSupported(const FrameType::PixelOrigin pixelOrigin);
 
        /**
         * Returns whether a given pixel format together with a given pixel origin is supported natively.
         * @param pixelFormat The pixel format to be checked
         * @param pixelOrigin The pixel origin to be checked
         * @return True, if so; False, if a conversion will be necessary
         */
        static inline bool isFrameTypeSupported(const FrameType::PixelFormat pixelFormat, const FrameType::PixelOrigin pixelOrigin);
 
    protected:
 
        /**
         * Reads the header of a NPY file.
         * @param data The data buffer, will be moved if the header could be read successfully, must be valid
         * @param size The size of the buffer in bytes, will be reduced if the header could be read successfully, must be valid
         * @param frameType The resulting frame type
         * @param isRowMajor True, if the data is given in row-major order; False, if the data is given in column-major order
         * @return True, if succeeded
         */
        static bool readHeader(const uint8_t*& data, size_t& size, FrameType& frameType, bool& isRowMajor);
 
        /**
         * Translates the pixel format.
         * @param pixelFormat The pixel format to be translated given as string
         * @return The resulting pixel format, FORMAT_UNDEFINED if unknown
         */
        static FrameType::PixelFormat translatePixelFormat(const std::string& pixelFormat);
 
        /**
         * Translates the pixel format.
         * @param pixelFormat The pixel format to be translated
         * @return The resulting pixel format as string, empty if unknown
         */
        static std::string translatePixelFormat(const FrameType::PixelFormat pixelFormat);
};
 
inline bool ImageNpy::isPixelFormatSupported(const FrameType::PixelFormat pixelFormat)
{
    return !translatePixelFormat(pixelFormat).empty();
}
 
inline bool ImageNpy::isPixelOriginSupported(const FrameType::PixelOrigin pixelOrigin)
{
    return pixelOrigin == FrameType::ORIGIN_UPPER_LEFT || pixelOrigin == FrameType::ORIGIN_LOWER_LEFT;
}
 
inline bool ImageNpy::isFrameTypeSupported(const FrameType::PixelFormat pixelFormat, const FrameType::PixelOrigin pixelOrigin)
{
    return isPixelFormatSupported(pixelFormat) && isPixelOriginSupported(pixelOrigin);
}
 
}
 
}
 
}
 
#endif // META_OCEAN_MEDIA_SPECIAL_IMAGE_NPY_H