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295 lines
17 KiB
C++
295 lines
17 KiB
C++
/*M///////////////////////////////////////////////////////////////////////////////////////
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//
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// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
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//
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// By downloading, copying, installing or using the software you agree to this license.
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// If you do not agree to this license, do not download, install,
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// copy or use the software.
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//
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//
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// License Agreement
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// For Open Source Computer Vision Library
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//
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// Copyright (C) 2000-2008, Intel Corporation, all rights reserved.
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// Copyright (C) 2009, Willow Garage Inc., all rights reserved.
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// Third party copyrights are property of their respective owners.
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//
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// Redistribution and use in source and binary forms, with or without modification,
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// are permitted provided that the following conditions are met:
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//
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// * Redistribution's of source code must retain the above copyright notice,
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// this list of conditions and the following disclaimer.
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//
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// * Redistribution's in binary form must reproduce the above copyright notice,
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// this list of conditions and the following disclaimer in the documentation
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// and/or other materials provided with the distribution.
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//
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// * The name of the copyright holders may not be used to endorse or promote products
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// derived from this software without specific prior written permission.
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//
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// This software is provided by the copyright holders and contributors "as is" and
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// any express or implied warranties, including, but not limited to, the implied
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// warranties of merchantability and fitness for a particular purpose are disclaimed.
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// In no event shall the Intel Corporation or contributors be liable for any direct,
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// indirect, incidental, special, exemplary, or consequential damages
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// (including, but not limited to, procurement of substitute goods or services;
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// loss of use, data, or profits; or business interruption) however caused
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// and on any theory of liability, whether in contract, strict liability,
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// or tort (including negligence or otherwise) arising in any way out of
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// the use of this software, even if advised of the possibility of such damage.
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//
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//M*/
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#ifndef OPENCV_IMGCODECS_HPP
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#define OPENCV_IMGCODECS_HPP
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#include "opencv2/core.hpp"
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/**
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@defgroup imgcodecs Image file reading and writing
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@{
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@defgroup imgcodecs_c C API
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@defgroup imgcodecs_flags Flags used for image file reading and writing
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@defgroup imgcodecs_ios iOS glue
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@defgroup imgcodecs_macosx MacOS(OSX) glue
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@}
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*/
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//////////////////////////////// image codec ////////////////////////////////
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namespace cv
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{
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//! @addtogroup imgcodecs
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//! @{
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//! @addtogroup imgcodecs_flags
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//! @{
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//! Imread flags
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enum ImreadModes {
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IMREAD_UNCHANGED = -1, //!< If set, return the loaded image as is (with alpha channel, otherwise it gets cropped). Ignore EXIF orientation.
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IMREAD_GRAYSCALE = 0, //!< If set, always convert image to the single channel grayscale image (codec internal conversion).
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IMREAD_COLOR = 1, //!< If set, always convert image to the 3 channel BGR color image.
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IMREAD_ANYDEPTH = 2, //!< If set, return 16-bit/32-bit image when the input has the corresponding depth, otherwise convert it to 8-bit.
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IMREAD_ANYCOLOR = 4, //!< If set, the image is read in any possible color format.
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IMREAD_LOAD_GDAL = 8, //!< If set, use the gdal driver for loading the image.
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IMREAD_REDUCED_GRAYSCALE_2 = 16, //!< If set, always convert image to the single channel grayscale image and the image size reduced 1/2.
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IMREAD_REDUCED_COLOR_2 = 17, //!< If set, always convert image to the 3 channel BGR color image and the image size reduced 1/2.
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IMREAD_REDUCED_GRAYSCALE_4 = 32, //!< If set, always convert image to the single channel grayscale image and the image size reduced 1/4.
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IMREAD_REDUCED_COLOR_4 = 33, //!< If set, always convert image to the 3 channel BGR color image and the image size reduced 1/4.
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IMREAD_REDUCED_GRAYSCALE_8 = 64, //!< If set, always convert image to the single channel grayscale image and the image size reduced 1/8.
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IMREAD_REDUCED_COLOR_8 = 65, //!< If set, always convert image to the 3 channel BGR color image and the image size reduced 1/8.
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IMREAD_IGNORE_ORIENTATION = 128 //!< If set, do not rotate the image according to EXIF's orientation flag.
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};
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//! Imwrite flags
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enum ImwriteFlags {
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IMWRITE_JPEG_QUALITY = 1, //!< For JPEG, it can be a quality from 0 to 100 (the higher is the better). Default value is 95.
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IMWRITE_JPEG_PROGRESSIVE = 2, //!< Enable JPEG features, 0 or 1, default is False.
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IMWRITE_JPEG_OPTIMIZE = 3, //!< Enable JPEG features, 0 or 1, default is False.
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IMWRITE_JPEG_RST_INTERVAL = 4, //!< JPEG restart interval, 0 - 65535, default is 0 - no restart.
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IMWRITE_JPEG_LUMA_QUALITY = 5, //!< Separate luma quality level, 0 - 100, default is 0 - don't use.
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IMWRITE_JPEG_CHROMA_QUALITY = 6, //!< Separate chroma quality level, 0 - 100, default is 0 - don't use.
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IMWRITE_PNG_COMPRESSION = 16, //!< For PNG, it can be the compression level from 0 to 9. A higher value means a smaller size and longer compression time. If specified, strategy is changed to IMWRITE_PNG_STRATEGY_DEFAULT (Z_DEFAULT_STRATEGY). Default value is 1 (best speed setting).
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IMWRITE_PNG_STRATEGY = 17, //!< One of cv::ImwritePNGFlags, default is IMWRITE_PNG_STRATEGY_RLE.
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IMWRITE_PNG_BILEVEL = 18, //!< Binary level PNG, 0 or 1, default is 0.
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IMWRITE_PXM_BINARY = 32, //!< For PPM, PGM, or PBM, it can be a binary format flag, 0 or 1. Default value is 1.
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IMWRITE_EXR_TYPE = (3 << 4) + 0, /* 48 */ //!< override EXR storage type (FLOAT (FP32) is default)
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IMWRITE_WEBP_QUALITY = 64, //!< For WEBP, it can be a quality from 1 to 100 (the higher is the better). By default (without any parameter) and for quality above 100 the lossless compression is used.
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IMWRITE_PAM_TUPLETYPE = 128,//!< For PAM, sets the TUPLETYPE field to the corresponding string value that is defined for the format
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IMWRITE_TIFF_RESUNIT = 256,//!< For TIFF, use to specify which DPI resolution unit to set; see libtiff documentation for valid values
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IMWRITE_TIFF_XDPI = 257,//!< For TIFF, use to specify the X direction DPI
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IMWRITE_TIFF_YDPI = 258, //!< For TIFF, use to specify the Y direction DPI
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IMWRITE_TIFF_COMPRESSION = 259, //!< For TIFF, use to specify the image compression scheme. See libtiff for integer constants corresponding to compression formats. Note, for images whose depth is CV_32F, only libtiff's SGILOG compression scheme is used. For other supported depths, the compression scheme can be specified by this flag; LZW compression is the default.
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IMWRITE_JPEG2000_COMPRESSION_X1000 = 272 //!< For JPEG2000, use to specify the target compression rate (multiplied by 1000). The value can be from 0 to 1000. Default is 1000.
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};
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enum ImwriteEXRTypeFlags {
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/*IMWRITE_EXR_TYPE_UNIT = 0, //!< not supported */
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IMWRITE_EXR_TYPE_HALF = 1, //!< store as HALF (FP16)
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IMWRITE_EXR_TYPE_FLOAT = 2 //!< store as FP32 (default)
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};
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//! Imwrite PNG specific flags used to tune the compression algorithm.
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/** These flags will be modify the way of PNG image compression and will be passed to the underlying zlib processing stage.
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- The effect of IMWRITE_PNG_STRATEGY_FILTERED is to force more Huffman coding and less string matching; it is somewhat intermediate between IMWRITE_PNG_STRATEGY_DEFAULT and IMWRITE_PNG_STRATEGY_HUFFMAN_ONLY.
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- IMWRITE_PNG_STRATEGY_RLE is designed to be almost as fast as IMWRITE_PNG_STRATEGY_HUFFMAN_ONLY, but give better compression for PNG image data.
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- The strategy parameter only affects the compression ratio but not the correctness of the compressed output even if it is not set appropriately.
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- IMWRITE_PNG_STRATEGY_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.
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*/
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enum ImwritePNGFlags {
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IMWRITE_PNG_STRATEGY_DEFAULT = 0, //!< Use this value for normal data.
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IMWRITE_PNG_STRATEGY_FILTERED = 1, //!< Use this value for data produced by a filter (or predictor).Filtered data consists mostly of small values with a somewhat random distribution. In this case, the compression algorithm is tuned to compress them better.
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IMWRITE_PNG_STRATEGY_HUFFMAN_ONLY = 2, //!< Use this value to force Huffman encoding only (no string match).
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IMWRITE_PNG_STRATEGY_RLE = 3, //!< Use this value to limit match distances to one (run-length encoding).
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IMWRITE_PNG_STRATEGY_FIXED = 4 //!< Using this value prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.
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};
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//! Imwrite PAM specific tupletype flags used to define the 'TUPETYPE' field of a PAM file.
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enum ImwritePAMFlags {
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IMWRITE_PAM_FORMAT_NULL = 0,
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IMWRITE_PAM_FORMAT_BLACKANDWHITE = 1,
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IMWRITE_PAM_FORMAT_GRAYSCALE = 2,
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IMWRITE_PAM_FORMAT_GRAYSCALE_ALPHA = 3,
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IMWRITE_PAM_FORMAT_RGB = 4,
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IMWRITE_PAM_FORMAT_RGB_ALPHA = 5,
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};
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//! @} imgcodecs_flags
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/** @brief Loads an image from a file.
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@anchor imread
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The function imread loads an image from the specified file and returns it. If the image cannot be
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read (because of missing file, improper permissions, unsupported or invalid format), the function
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returns an empty matrix ( Mat::data==NULL ).
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Currently, the following file formats are supported:
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- Windows bitmaps - \*.bmp, \*.dib (always supported)
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- JPEG files - \*.jpeg, \*.jpg, \*.jpe (see the *Note* section)
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- JPEG 2000 files - \*.jp2 (see the *Note* section)
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- Portable Network Graphics - \*.png (see the *Note* section)
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- WebP - \*.webp (see the *Note* section)
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- Portable image format - \*.pbm, \*.pgm, \*.ppm \*.pxm, \*.pnm (always supported)
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- PFM files - \*.pfm (see the *Note* section)
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- Sun rasters - \*.sr, \*.ras (always supported)
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- TIFF files - \*.tiff, \*.tif (see the *Note* section)
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- OpenEXR Image files - \*.exr (see the *Note* section)
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- Radiance HDR - \*.hdr, \*.pic (always supported)
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- Raster and Vector geospatial data supported by GDAL (see the *Note* section)
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@note
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- The function determines the type of an image by the content, not by the file extension.
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- In the case of color images, the decoded images will have the channels stored in **B G R** order.
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- When using IMREAD_GRAYSCALE, the codec's internal grayscale conversion will be used, if available.
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Results may differ to the output of cvtColor()
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- On Microsoft Windows\* OS and MacOSX\*, the codecs shipped with an OpenCV image (libjpeg,
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libpng, libtiff, and libjasper) are used by default. So, OpenCV can always read JPEGs, PNGs,
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and TIFFs. On MacOSX, there is also an option to use native MacOSX image readers. But beware
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that currently these native image loaders give images with different pixel values because of
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the color management embedded into MacOSX.
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- On Linux\*, BSD flavors and other Unix-like open-source operating systems, OpenCV looks for
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codecs supplied with an OS image. Install the relevant packages (do not forget the development
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files, for example, "libjpeg-dev", in Debian\* and Ubuntu\*) to get the codec support or turn
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on the OPENCV_BUILD_3RDPARTY_LIBS flag in CMake.
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- In the case you set *WITH_GDAL* flag to true in CMake and @ref IMREAD_LOAD_GDAL to load the image,
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then the [GDAL](http://www.gdal.org) driver will be used in order to decode the image, supporting
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the following formats: [Raster](http://www.gdal.org/formats_list.html),
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[Vector](http://www.gdal.org/ogr_formats.html).
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- If EXIF information is embedded in the image file, the EXIF orientation will be taken into account
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and thus the image will be rotated accordingly except if the flags @ref IMREAD_IGNORE_ORIENTATION
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or @ref IMREAD_UNCHANGED are passed.
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- Use the IMREAD_UNCHANGED flag to keep the floating point values from PFM image.
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- By default number of pixels must be less than 2^30. Limit can be set using system
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variable OPENCV_IO_MAX_IMAGE_PIXELS
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@param filename Name of file to be loaded.
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@param flags Flag that can take values of cv::ImreadModes
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*/
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CV_EXPORTS_W Mat imread( const String& filename, int flags = IMREAD_COLOR );
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/** @brief Loads a multi-page image from a file.
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The function imreadmulti loads a multi-page image from the specified file into a vector of Mat objects.
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@param filename Name of file to be loaded.
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@param flags Flag that can take values of cv::ImreadModes, default with cv::IMREAD_ANYCOLOR.
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@param mats A vector of Mat objects holding each page, if more than one.
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@sa cv::imread
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*/
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CV_EXPORTS_W bool imreadmulti(const String& filename, CV_OUT std::vector<Mat>& mats, int flags = IMREAD_ANYCOLOR);
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/** @brief Saves an image to a specified file.
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The function imwrite saves the image to the specified file. The image format is chosen based on the
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filename extension (see cv::imread for the list of extensions). In general, only 8-bit
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single-channel or 3-channel (with 'BGR' channel order) images
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can be saved using this function, with these exceptions:
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- 16-bit unsigned (CV_16U) images can be saved in the case of PNG, JPEG 2000, and TIFF formats
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- 32-bit float (CV_32F) images can be saved in PFM, TIFF, OpenEXR, and Radiance HDR formats;
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3-channel (CV_32FC3) TIFF images will be saved using the LogLuv high dynamic range encoding
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(4 bytes per pixel)
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- PNG images with an alpha channel can be saved using this function. To do this, create
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8-bit (or 16-bit) 4-channel image BGRA, where the alpha channel goes last. Fully transparent pixels
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should have alpha set to 0, fully opaque pixels should have alpha set to 255/65535 (see the code sample below).
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- Multiple images (vector of Mat) can be saved in TIFF format (see the code sample below).
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If the format, depth or channel order is different, use
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Mat::convertTo and cv::cvtColor to convert it before saving. Or, use the universal FileStorage I/O
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functions to save the image to XML or YAML format.
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The sample below shows how to create a BGRA image, how to set custom compression parameters and save it to a PNG file.
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It also demonstrates how to save multiple images in a TIFF file:
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@include snippets/imgcodecs_imwrite.cpp
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@param filename Name of the file.
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@param img (Mat or vector of Mat) Image or Images to be saved.
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@param params Format-specific parameters encoded as pairs (paramId_1, paramValue_1, paramId_2, paramValue_2, ... .) see cv::ImwriteFlags
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*/
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CV_EXPORTS_W bool imwrite( const String& filename, InputArray img,
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const std::vector<int>& params = std::vector<int>());
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/// @overload multi-image overload for bindings
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CV_WRAP static inline
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bool imwritemulti(const String& filename, InputArrayOfArrays img,
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const std::vector<int>& params = std::vector<int>())
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{
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return imwrite(filename, img, params);
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}
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/** @brief Reads an image from a buffer in memory.
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The function imdecode reads an image from the specified buffer in the memory. If the buffer is too short or
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contains invalid data, the function returns an empty matrix ( Mat::data==NULL ).
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See cv::imread for the list of supported formats and flags description.
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@note In the case of color images, the decoded images will have the channels stored in **B G R** order.
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@param buf Input array or vector of bytes.
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@param flags The same flags as in cv::imread, see cv::ImreadModes.
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*/
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CV_EXPORTS_W Mat imdecode( InputArray buf, int flags );
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/** @overload
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@param buf
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@param flags
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@param dst The optional output placeholder for the decoded matrix. It can save the image
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reallocations when the function is called repeatedly for images of the same size.
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*/
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CV_EXPORTS Mat imdecode( InputArray buf, int flags, Mat* dst);
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/** @brief Encodes an image into a memory buffer.
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The function imencode compresses the image and stores it in the memory buffer that is resized to fit the
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result. See cv::imwrite for the list of supported formats and flags description.
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@param ext File extension that defines the output format.
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@param img Image to be written.
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@param buf Output buffer resized to fit the compressed image.
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@param params Format-specific parameters. See cv::imwrite and cv::ImwriteFlags.
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*/
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CV_EXPORTS_W bool imencode( const String& ext, InputArray img,
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CV_OUT std::vector<uchar>& buf,
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const std::vector<int>& params = std::vector<int>());
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/** @brief Returns true if the specified image can be decoded by OpenCV
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@param filename File name of the image
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*/
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CV_EXPORTS_W bool haveImageReader( const String& filename );
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/** @brief Returns true if an image with the specified filename can be encoded by OpenCV
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@param filename File name of the image
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*/
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CV_EXPORTS_W bool haveImageWriter( const String& filename );
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//! @} imgcodecs
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} // cv
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#endif //OPENCV_IMGCODECS_HPP
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