1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include <vector>
20 #include <iostream>
21 #include <fstream>
22 #include <sstream>
23 #include <memory.h>
24 
25 /*!
26  * Simple class to manipulate PGM/PPM images. Not suitable for heavy lifting.
27  */
28 class PgmImage
29 {
30     friend std::ostream& operator<< (std::ostream& o, const PgmImage& im);
31 public:
32     enum {PGM_BINARY_GRAYMAP,PGM_BINARY_PIXMAP,PGM_FORMAT_INVALID};
33     /*!
34     * Constructor from a PGM file name.
35     */
36     PgmImage(std::string filename);
37     /*!
38     * Constructor to allocate an image of given size and type.
39     */
40     PgmImage(int w, int h, int format = PGM_BINARY_GRAYMAP);
41     /*!
42     * Constructor to allocate an image of given size and copy the data in.
43     */
44     PgmImage(unsigned char *data, int w, int h);
45     /*!
46     * Constructor to allocate an image of given size and copy the data in.
47     */
48     PgmImage(std::vector<unsigned char> &data, int w, int h);
49 
50     PgmImage(const PgmImage &im);
51 
52     PgmImage& operator= (const PgmImage &im);
53     ~PgmImage();
54 
GetHeight()55     int GetHeight() const { return m_h; }
GetWidth()56     int GetWidth() const { return m_w; }
57 
58     //! Copy pixels from data pointer
59     void SetData(const unsigned char * data);
60 
61     //! Get a data pointer to unaligned memory area
GetDataPointer()62     unsigned char * GetDataPointer() { if ( m_data.size() > 0 ) return &m_data[0]; else return NULL; }
GetRowPointers()63     unsigned char ** GetRowPointers() { if ( m_rows.size() == m_h ) return &m_rows[0]; else return NULL; }
64 
65     //! Read a PGM file from disk
66     bool ReadPGM(const std::string filename);
67     //! Write a PGM file to disk
68     bool WritePGM(const std::string filename, const std::string comment="");
69 
70     //! Get image format (returns PGM_BINARY_GRAYMAP, PGM_BINARY_PIXMAP or PGM_FORMAT_INVALID)
GetFormat()71     int GetFormat() const { return m_format; }
72 
73     //! Set image format (returns PGM_BINARY_GRAYMAP, PGM_BINARY_PIXMAP). Image data becomes invalid.
74     void SetFormat(int format);
75 
76     //! If the image is PGM_BINARY_PIXMAP, convert it to PGM_BINARY_GRAYMAP via Y = 0.3*R + 0.59*G + 0.11*B.
77     void ConvertToGray();
78 protected:
79     // Generic functions:
80     void DeepCopy(const PgmImage& src, PgmImage& dst);
81     void SetupRowPointers();
82 
83     // PGM data
84     int m_w;
85     int m_h;
86     int m_format;
87     int m_colors;
88     int m_over_allocation;
89     std::vector<unsigned char> m_data;
90     std::string m_comment;
91 
92     std::vector<unsigned char *> m_rows;
93 };
94 
95 std::ostream& operator<< (std::ostream& o, const PgmImage& im);
96