imgcodecs: Implementation of PAM encoder/decoder

This patch implements the PAM image format as defined at:
http://netpbm.sourceforge.net/doc/pam.html

The PAM format provides a generic means for storing 2 dimensional information.
This is useful for opencv since there are cases where data gets translated into
non standardized formats, which makes it difficult to store and load this information.

modules/imgcodecs/include/opencv2/imgcodecs.hpp

@@ -88,7 +88,8 @@ enum ImwriteFlags {
        IMWRITE_PNG_STRATEGY        = 17, //!< One of cv::ImwritePNGFlags, default is IMWRITE_PNG_STRATEGY_DEFAULT.
        IMWRITE_PNG_BILEVEL         = 18, //!< Binary level PNG, 0 or 1, default is 0.
        IMWRITE_PXM_BINARY          = 32, //!< For PPM, PGM, or PBM, it can be a binary format flag, 0 or 1. Default value is 1.
-       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.
+       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.
+       IMWRITE_PAM_TUPLETYPE       = 128,//!< For PAM, sets the TUPLETYPE field to the corresponding string value that is defined for the format
      };
 
 //! Imwrite PNG specific flags used to tune the compression algorithm.
@@ -107,6 +108,16 @@ enum ImwritePNGFlags {
        IMWRITE_PNG_STRATEGY_FIXED        = 4  //!< Using this value prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.
      };
 
+//! Imwrite PAM specific tupletype flags used to define the 'TUPETYPE' field of a PAM file.
+enum ImwritePAMFlags {
+       IMWRITE_PAM_FORMAT_NULL = 0,
+       IMWRITE_PAM_FORMAT_BLACKANDWHITE = 1,
+       IMWRITE_PAM_FORMAT_GRAYSCALE = 2,
+       IMWRITE_PAM_FORMAT_GRAYSCALE_ALPHA = 3,
+       IMWRITE_PAM_FORMAT_RGB = 4,
+       IMWRITE_PAM_FORMAT_RGB_ALPHA = 5,
+     };
+
 /** @brief Loads an image from a file.
 
 @anchor imread

modules/imgcodecs/include/opencv2/imgcodecs/imgcodecs_c.h

@@ -92,9 +92,18 @@ enum
     CV_IMWRITE_PNG_STRATEGY_RLE =3,
     CV_IMWRITE_PNG_STRATEGY_FIXED =4,
     CV_IMWRITE_PXM_BINARY =32,
-    CV_IMWRITE_WEBP_QUALITY =64
+    CV_IMWRITE_WEBP_QUALITY =64,
+    CV_IMWRITE_PAM_TUPLETYPE = 128,
+    CV_IMWRITE_PAM_FORMAT_NULL = 0,
+    CV_IMWRITE_PAM_FORMAT_BLACKANDWHITE = 1,
+    CV_IMWRITE_PAM_FORMAT_GRAYSCALE = 2,
+    CV_IMWRITE_PAM_FORMAT_GRAYSCALE_ALPHA = 3,
+    CV_IMWRITE_PAM_FORMAT_RGB = 4,
+    CV_IMWRITE_PAM_FORMAT_RGB_ALPHA = 5,
 };
 
+
+
 /* save image to file */
 CVAPI(int) cvSaveImage( const char* filename, const CvArr* image,
                         const int* params CV_DEFAULT(0) );

modules/imgcodecs/src/grfmt_pam.hpp

+/*M///////////////////////////////////////////////////////////////////////////////////////
+//
+//  IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING.
+//
+//  By downloading, copying, installing or using the software you agree to this license.
+//  If you do not agree to this license, do not download, install,
+//  copy or use the software.
+//
+//
+//                            License Agreement
+//                 For Open Source Computer Vision Library
+//                         (3-clause BSD License)
+//
+//  Copyright (C) 2000-2016, Intel Corporation, all rights reserved.
+//  Copyright (C) 2009-2011, Willow Garage Inc., all rights reserved.
+//  Copyright (C) 2009-2016, NVIDIA Corporation, all rights reserved.
+//  Copyright (C) 2010-2013, Advanced Micro Devices, Inc., all rights reserved.
+//  Copyright (C) 2015-2016, OpenCV Foundation, all rights reserved.
+//  Copyright (C) 2015-2016, Itseez Inc., all rights reserved.
+//  Third party copyrights are property of their respective owners.
+//
+//  Redistribution and use in source and binary forms, with or without modification,
+//  are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright notice,
+//      this list of conditions and the following disclaimer.
+//
+//    * Redistributions in binary form must reproduce the above copyright notice,
+//      this list of conditions and the following disclaimer in the documentation
+//      and/or other materials provided with the distribution.
+//
+//    * Neither the names of the copyright holders nor the names of the contributors
+//      may be used to endorse or promote products derived from this software
+//      without specific prior written permission.
+//
+//  This software is provided by the copyright holders and contributors "as is" and
+//  any express or implied warranties, including, but not limited to, the implied
+//  warranties of merchantability and fitness for a particular purpose are disclaimed.
+//  In no event shall copyright holders or contributors be liable for any direct,
+//  indirect, incidental, special, exemplary, or consequential damages
+//  (including, but not limited to, procurement of substitute goods or services;
+//  loss of use, data, or profits; or business interruption) however caused
+//  and on any theory of liability, whether in contract, strict liability,
+//  or tort (including negligence or otherwise) arising in any way out of
+//  the use of this software, even if advised of the possibility of such damage.
+//
+//
+//M*/
+
+//Based on "imgcodecs/src/grfmt_pxm.hpp"
+//Written by Dimitrios Katsaros <patcherwork@gmail.com>
+
+#ifndef _OPENCV_PAM_HPP_
+#define _OPENCV_PAM_HPP_
+
+#include "grfmt_base.hpp"
+#include "bitstrm.hpp"
+
+namespace cv
+{
+
+class PAMDecoder : public BaseImageDecoder
+{
+public:
+
+    PAMDecoder();
+    virtual ~PAMDecoder();
+
+    bool  readData( Mat& img );
+    bool  readHeader();
+
+    size_t signatureLength() const;
+    bool checkSignature( const String& signature ) const;
+    ImageDecoder newDecoder() const;
+
+protected:
+
+    RLByteStream    m_strm;
+    int m_maxval, m_channels, m_sampledepth, m_offset,
+        selected_fmt;
+    bool bit_mode;
+};
+
+
+class PAMEncoder : public BaseImageEncoder
+{
+public:
+    PAMEncoder();
+    virtual ~PAMEncoder();
+
+    bool  isFormatSupported( int depth ) const;
+    bool  write( const Mat& img, const std::vector<int>& params );
+
+    ImageEncoder newEncoder() const;
+};
+
+}
+
+#endif /* _OPENCV_PAM_HPP_ */
\ No newline at end of file

modules/imgcodecs/src/grfmts.hpp

@@ -55,5 +55,6 @@
 #include "grfmt_hdr.hpp"
 #include "grfmt_gdal.hpp"
 #include "grfmt_gdcm.hpp"
+#include "grfmt_pam.hpp"
 
 #endif/*_GRFMTS_H_*/

modules/imgcodecs/src/loadsave.cpp

@@ -109,6 +109,8 @@ struct ImageCodecInitializer
         /// Attach the GDAL Decoder
         decoders.push_back( makePtr<GdalDecoder>() );
     #endif/*HAVE_GDAL*/
+        decoders.push_back( makePtr<PAMDecoder>() );
+        encoders.push_back( makePtr<PAMEncoder>() );
     }
 
     std::vector<ImageDecoder> decoders;