1 | #include <png.h>
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2 | #include <stdio.h>
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3 | #include <setjmp.h>
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4 |
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5 | #define file_name "test.png"
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6 |
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7 | #define ERROR 1
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8 |
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9 | png_byte data0[] = { 0, 10, 20, 30 },
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10 | data1[] = { 10, 25, 40, 55 },
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11 | data2[] = { 20, 40, 60, 80 },
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12 | data3[] = { 30, 55, 80, 105 };
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13 |
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14 | png_byte *row_pointers[4] = {
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15 | data0, data1, data2, data3
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16 | };
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17 |
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18 | void write_row_callback(png_structp png_ptr, png_uint_32 row,
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19 | int pass)
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20 | {
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21 | /* put your code here */
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22 | }
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23 |
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24 | int
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25 | main(void)
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26 | {
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27 | FILE *fp = fopen(file_name, "wb");
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28 | if (!fp)
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29 | {
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30 | return (ERROR);
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31 | }
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32 |
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33 | png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL,
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34 | NULL, NULL);
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35 | if (!png_ptr)
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36 | return (ERROR);
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37 |
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38 | png_infop info_ptr = png_create_info_struct(png_ptr);
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39 | if (!info_ptr)
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40 | {
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41 | png_destroy_write_struct(&png_ptr,
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42 | (png_infopp)NULL);
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43 | return (ERROR);
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44 | }
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45 | if (setjmp(png_jmpbuf(png_ptr)))
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46 | {
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47 | png_destroy_write_struct(&png_ptr, &info_ptr);
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48 | fclose(fp);
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49 | return (ERROR);
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50 | }
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51 | png_init_io(png_ptr, fp);
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52 |
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53 | png_set_write_status_fn(png_ptr, write_row_callback);
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54 |
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55 | /* turn on or off filtering, and/or choose
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56 | specific filters. You can use either a single
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57 | PNG_FILTER_VALUE_NAME or the bitwise OR of one
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58 | or more PNG_FILTER_NAME masks. */
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59 | #if 0
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60 | png_set_filter(png_ptr, 0,
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61 | PNG_FILTER_NONE | PNG_FILTER_VALUE_NONE |
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62 | PNG_FILTER_SUB | PNG_FILTER_VALUE_SUB |
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63 | PNG_FILTER_UP | PNG_FILTER_VALUE_UP |
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64 | PNG_FILTER_AVG | PNG_FILTER_VALUE_AVG |
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65 | PNG_FILTER_PAETH | PNG_FILTER_VALUE_PAETH|
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66 | PNG_ALL_FILTERS);
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67 | #endif
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68 | /* set the zlib compression level */
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69 | png_set_compression_level(png_ptr,
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70 | Z_BEST_COMPRESSION);
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71 |
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72 | /* set other zlib parameters */
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73 | png_set_compression_mem_level(png_ptr, 8);
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74 | png_set_compression_strategy(png_ptr,
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75 | Z_DEFAULT_STRATEGY);
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76 | png_set_compression_window_bits(png_ptr, 15);
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77 | png_set_compression_method(png_ptr, 8);
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78 | png_set_compression_buffer_size(png_ptr, 8192);
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79 |
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80 | png_set_IHDR(png_ptr, info_ptr,
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81 | 4, 4, /* width, height */
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82 | 8, /* bit_depth */
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83 | PNG_COLOR_TYPE_GRAY,
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84 | PNG_INTERLACE_NONE,
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85 | PNG_COMPRESSION_TYPE_DEFAULT,
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86 | PNG_FILTER_TYPE_DEFAULT);
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87 | png_write_info(png_ptr, info_ptr);
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88 | png_write_image(png_ptr, row_pointers);
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89 |
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90 | png_write_end(png_ptr, info_ptr);
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91 | png_destroy_write_struct(&png_ptr, &info_ptr);
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92 |
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93 | fclose(fp);
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94 |
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95 | return 0;
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96 | }
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