1 | //-*-c++-*- |
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2 | |
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3 | #ifndef _PNM_H |
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4 | #define _PNM_H |
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5 | |
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6 | #include "Rectify/Ops.h" |
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7 | |
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8 | #include <iostream> |
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9 | #include <string> |
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10 | |
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11 | class PNMLoadSave { |
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12 | |
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13 | private: |
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14 | |
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15 | // Skip over spaces and comments; temp is the current file character |
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16 | static void SkipSpaces(std::ifstream& file, signed char& temp) |
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17 | { |
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18 | while (temp == ' ' || temp == '\t' || temp == '\n' || temp == '#') |
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19 | { |
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20 | if (file.eof()) |
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21 | return; |
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22 | if (temp == '#') // skip this line: |
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23 | while ((temp != '\n') && (temp != EOF)) |
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24 | temp=file.get(); |
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25 | // skip this `whitespace' byte: |
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26 | temp=file.get(); |
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27 | } |
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28 | } |
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29 | |
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30 | // Get an integer from the file stream; temp is the current file character |
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31 | static int ReadInteger(std::ifstream& file, signed char& temp) |
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32 | { |
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33 | int n = 0; |
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34 | bool neg=false; |
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35 | while (((temp >= '0') && (temp <= '9')) || (temp == '-')) |
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36 | { |
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37 | if (file.eof()) |
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38 | return 0; |
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39 | if (temp=='-') |
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40 | neg=true; |
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41 | n *= 10; n += (temp - '0'); |
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42 | temp=file.get(); |
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43 | } |
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44 | if (neg) |
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45 | n=-n; |
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46 | return n; |
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47 | } |
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48 | |
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49 | struct pgm_image_header |
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50 | { |
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51 | char magic_number[2]; // magic number |
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52 | int height; // number of scan lines |
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53 | int width; // scan line length |
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54 | int maxval; |
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55 | }; |
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56 | |
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57 | public: |
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58 | |
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59 | /// Load the image in the given filename. If succeeds, image is filled and returns true. Returns false otherwise |
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60 | template <class DataT> |
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61 | static bool LoadImage(const std::string &filename, Image::Image<DataT> &image) { |
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62 | // assume filename already verified |
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63 | std::ifstream file(filename.c_str(), std::ios::in | std::ios::binary); |
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64 | if (!file) { |
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65 | std::cerr << "Couldn't open file '" << filename << "' for reading image" << std::endl; |
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66 | exit(1); |
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67 | } |
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68 | |
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69 | unsigned int xsize, ysize, bitspp, magicnumber; |
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70 | bool colour; |
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71 | |
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72 | colour=false; // PGM is greyscale by default |
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73 | signed char temp; |
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74 | |
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75 | /** READ THE HEADER **/ |
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76 | |
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77 | //This method assumes the PGM header is in the following format |
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78 | //P[25] |
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79 | //#comments |
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80 | //#up to any amount of comments (including no comments) |
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81 | //width height |
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82 | //maxval |
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83 | file.seekg(0, std::ios::beg); |
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84 | //Because PGM Image files can contain an unlimited number of |
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85 | //comments, this method of reading in the header is infeasible |
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86 | //It was left in to read in the magic number |
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87 | pgm_image_header header; |
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88 | file.read((char*)(&header), sizeof(header)); |
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89 | |
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90 | if ((header.magic_number[0]!='P') || (!file)) { |
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91 | std::cerr << "Couldn't open image file! " << std::endl; |
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92 | exit(1); |
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93 | } |
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94 | magicnumber=header.magic_number[1]-'0'; |
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95 | if (magicnumber!=2 && magicnumber!=3 && magicnumber!=5 && magicnumber!=6) { |
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96 | std::cerr << "Couldn't open pnm image file because found bad magic number: only 2,3,5,6 recognised" << std::endl; |
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97 | exit(1); |
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98 | } |
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99 | |
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100 | file.seekg(3, std::ios::beg); |
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101 | temp=file.get(); |
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102 | |
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103 | //Skip over spaces and comments |
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104 | SkipSpaces(file,temp); |
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105 | //Read in Width |
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106 | xsize=(unsigned int)ReadInteger(file,temp); |
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107 | //Skip over spaces and comments |
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108 | SkipSpaces(file,temp); |
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109 | //Read in Height |
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110 | ysize=ReadInteger(file,temp); |
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111 | //Skip over spaces and comments |
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112 | SkipSpaces(file,temp); |
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113 | //Read in Maxval |
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114 | unsigned int maxval=ReadInteger(file,temp); |
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115 | |
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116 | if (temp == ' ' || temp == '\t' || temp == '\n') |
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117 | temp=file.get(); |
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118 | |
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119 | // Step the file back one. |
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120 | file.seekg(-1,std::ios::cur); |
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121 | |
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122 | if (maxval==0) |
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123 | bitspp=8; |
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124 | else |
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125 | { |
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126 | bitspp=0; |
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127 | while (maxval>0) |
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128 | { |
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129 | bitspp++; maxval=maxval>>1; |
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130 | } |
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131 | } |
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132 | |
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133 | /** DONE READING THE HEADER **/ |
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134 | |
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135 | if (magicnumber==3 || magicnumber==6) { |
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136 | // Colour so must have 3 of those samples per pixel |
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137 | bitspp=bitspp*3; |
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138 | colour=true; |
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139 | } |
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140 | |
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141 | image.resize(xsize, ysize, colour); |
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142 | |
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143 | // Every image should have 1D access unless the image class is written by a retard |
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144 | // However, I'm going to assume retard level and simply assume a 1D block for the image at (0,0) |
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145 | // so don't add unnecesary functions to Image.h and freak those retards out |
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146 | if (magicnumber==2) |
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147 | { |
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148 | DataT TempStore; |
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149 | DataT *oiter=&(image(0,0)), *containerend=oiter+(xsize*ysize); |
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150 | |
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151 | while (!file.eof() && oiter!=containerend) { |
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152 | // Problems with my gcc unless copy to a temp - probably optimisations or something |
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153 | file >> TempStore; |
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154 | *oiter++=TempStore; |
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155 | } |
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156 | } |
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157 | if (magicnumber==3) |
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158 | { |
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159 | DataT R,G,B; |
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160 | |
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161 | DataT *oiter=&(image(0,0)), *containerend=oiter+(xsize*ysize); |
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162 | while (!file.eof() && oiter!=containerend) { |
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163 | file >> R >> G >> B; |
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164 | *oiter++=(R<<16)+(G<<8)+B; |
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165 | } |
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166 | } |
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167 | if (magicnumber==5) |
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168 | { |
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169 | DataT *oiter=&(image(0,0)), *containerend=oiter+(xsize*ysize); |
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170 | while (!file.eof() && oiter!=containerend) |
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171 | *oiter++=file.get(); |
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172 | } |
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173 | if (magicnumber==6) |
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174 | { |
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175 | DataT *oiter=&(image(0,0)), *containerend=oiter+(xsize*ysize); |
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176 | while (!file.eof() && oiter!=containerend) |
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177 | *oiter++=(file.get()<<16)+(file.get()<<8)+file.get(); |
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178 | } |
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179 | |
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180 | if (!(file.good()) && !(file.eof())) |
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181 | return false; |
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182 | |
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183 | return true; |
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184 | } |
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185 | |
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186 | // Save an image to the given file. |
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187 | template <class DataT> |
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188 | static void SaveImage(const std::string &filename, const Image::Image<DataT> &image) { |
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189 | std::ofstream file(filename.c_str(), std::ios::out | std::ios::binary); |
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190 | if (!file) { |
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191 | std::cerr << "Couldn't open file '" << filename << "' for writing image" << std::endl; |
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192 | exit(1); |
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193 | } |
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194 | |
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195 | if (!image.isColour()) { |
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196 | DataT maxval=0; |
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197 | // Get bits per pixel for container based on max value if greyscale |
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198 | for (size_t x=0;x<image.xsize();++x) { |
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199 | for (size_t y=0;y<image.ysize();++y) { |
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200 | if (image(x,y)>maxval) |
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201 | maxval=image(x,y); |
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202 | } |
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203 | } |
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204 | // Get bits per pixel based on maximum value in the image |
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205 | unsigned int bpp=0; |
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206 | while (maxval>0) { |
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207 | ++bpp; |
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208 | maxval=maxval>>1; |
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209 | } |
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210 | |
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211 | // Write magic number. |
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212 | if (bpp==8) |
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213 | file << "P5" << std::endl; |
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214 | else |
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215 | file << "P2" << std::endl; |
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216 | |
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217 | // Write comments |
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218 | file << "# Created by some nice code" << std::endl; |
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219 | |
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220 | // Write Height and Width |
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221 | file << (unsigned int)image.xsize() << " " << (unsigned int)image.ysize() << std::endl; |
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222 | |
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223 | // Write max val |
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224 | if (bpp<32) |
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225 | file << (1<<bpp)-1 << std::endl; |
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226 | else |
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227 | file << UINT_MAX << std::endl; |
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228 | |
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229 | if (bpp==8) { |
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230 | char *buffer=new char[image.xsize()*image.ysize()]; |
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231 | char *iter=buffer; |
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232 | for (size_t y=0;y<image.ysize();++y) |
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233 | for (size_t x=0;x<image.xsize();++x) |
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234 | *iter++=image(x,y); |
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235 | file.write(buffer, ((std::streamsize)(image.xsize()*image.ysize()))); |
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236 | delete[] buffer; |
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237 | } |
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238 | else |
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239 | { |
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240 | for (size_t y=0;y<image.ysize();++y) |
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241 | for (size_t x=0;x<image.xsize();++x) |
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242 | file << image(x,y) << std::endl; |
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243 | } |
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244 | } |
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245 | else |
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246 | { |
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247 | |
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248 | file << "P6" << std::endl; |
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249 | |
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250 | // Write comments |
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251 | file << "# Created by some nice code" << std::endl; |
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252 | |
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253 | // Write Height and Width |
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254 | file << (unsigned int)image.xsize() << " " << (unsigned int)image.ysize() << std::endl; |
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255 | |
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256 | // Write max val |
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257 | file << "255" << std::endl; |
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258 | |
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259 | for (size_t y=0;y<image.ysize();++y) |
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260 | for (size_t x=0;x<image.xsize();++x) { |
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261 | DataT imval=image(x,y); |
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262 | file.put((imval & (255<<16))>>16); |
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263 | file.put((imval & (255<<8))>>8); |
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264 | file.put(imval & 255); |
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265 | } |
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266 | } |
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267 | |
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268 | if (!file) { |
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269 | std::cerr << "Filesystem error whilst writing image: " << filename << std::endl; |
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270 | exit(1); |
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271 | } |
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272 | |
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273 | return; |
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274 | |
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275 | } |
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276 | |
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277 | }; |
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278 | |
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279 | #endif |
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