Boojum

 

using namespace std;

using namespace Magick;

 

static const int steps_in_x = 23;

static const int steps_in_y = 23;

static const int steps_in_red = 4;

static const int steps_in_green = 4;

static const int steps_in_blue = 4;

static const int blocks_in_x = 11;

static const int blocks_in_y = 11;

static const int maximum_width = 1000;

static const int maximum_height = 1000;

 

static const int color_weight_a = 1;

static const int color_weight_b = 2;

static const int iterations = 15;

 

struct block

    int orientation;

    int x, y;

    int red, green, blue;

    long long int error;

} blocks[ blocks_in_y ][ blocks_in_x ];

int image_width, image_height;

 

static const int number_assigned = 100385;

static const int codes[] =

 

    32, 6, 1, 21, 1, 1, 1, 705, 112, 8, 2, 5, 5, 7, 1, 1, 1, 20, 1, 224, 7, 154, 13, 38, 2, 7, 1, 39, 1, 2, 6, 55, 8, 27, 5,

    5, 11, 4, 2, 22, 2, 2, 1, 62, 1, 174, 1, 60, 2, 101, 14, 43, 9, 7, 262, 57, 2, 18, 2, 5, 3, 27, 8, 5, 1, 3, 1, 8, 2,

    2, 2, 22, 1, 7, 1, 1, 3, 4, 2, 9, 2, 2, 2, 4, 8, 1, 4, 2, 1, 5, 2, 21, 6, 3, 1, 6, 4, 2, 2, 22, 1, 7, 1, 2, 1, 2, 1,

    2, 2, 1, 1, 5, 4, 2, 2, 3, 3, 1, 7, 4, 1, 1, 7, 16, 11, 3, 1, 9, 1, 3, 1, 22, 1, 7, 1, 2, 1, 5, 2, 10, 1, 3, 1, 3,

    2, 1, 15, 4, 2, 10, 1, 1, 15, 3, 1, 8, 2, 2, 2, 22, 1, 7, 1, 2, 1, 5, 2, 9, 2, 2, 2, 3, 8, 2, 4, 2, 1, 5, 2, 12, 16,

    2, 1, 6, 3, 3, 1, 4, 3, 2, 1, 1, 1, 2, 3, 2, 3, 3, 3, 12, 4, 5, 3, 3, 1, 4, 2, 1, 6, 1, 14, 21, 6, 3, 1, 8, 1, 3, 1,

    23, 1, 10, 1, 5, 3, 8, 1, 3, 1, 4, 7, 2, 1, 2, 6, 4, 2, 10, 8, 8, 2, 2, 1, 8, 1, 3, 1, 23, 1, 10, 1, 5, 2, 9, 1, 3,

    1, 4, 7, 2, 7, 1, 1, 4, 2, 10, 1, 2, 15, 2, 1, 8, 1, 3, 1, 23, 1, 16, 3, 8, 1, 3, 1, 4, 9, 1, 8, 4, 2, 16, 3, 7, 2,

    2, 1, 18, 3, 24, 1, 9, 1, 1, 2, 7, 3, 1, 4, 6, 1, 1, 1, 8, 18, 3, 12, 58, 4, 29, 37, 2, 1, 1, 2, 2, 1, 1, 2, 1, 6,

    4, 1, 7, 1, 3, 1, 1, 1, 1, 2, 2, 1, 13, 1, 3, 2, 5, 1, 1, 1, 6, 2, 10, 2, 2, 34, 72, 1, 36, 4, 27, 4, 8, 1, 36, 1,

    15, 1, 7, 43, 154, 4, 40, 10, 45, 3, 90, 5, 68, 5, 82, 6, 73, 1, 4, 2, 7, 1, 1, 1, 4, 2, 41, 1, 4, 2, 33, 1, 4, 2,

    7, 1, 1, 1, 4, 2, 15, 1, 57, 1, 4, 2, 67, 5, 29, 3, 26, 6, 85, 12, 630, 9, 29, 3, 81, 15, 13, 1, 7, 11, 23, 9, 20,

    12, 13, 1, 3, 1, 2, 12, 94, 2, 10, 6, 10, 6, 15, 1, 10, 6, 88, 8, 43, 85, 29, 3, 12, 4, 12, 4, 1, 3, 42, 2, 5, 11,

    42, 6, 26, 6, 10, 4, 62, 2, 2, 224, 76, 4, 27, 9, 9, 3, 43, 3, 12, 70, 56, 3, 15, 3, 51, 128, 192, 64, 278, 2, 6, 2,

    38, 2, 6, 2, 8, 1, 1, 1, 1, 1, 1, 1, 31, 2, 53, 1, 15, 1, 14, 2, 6, 1, 19, 2, 3, 1, 9, 1, 101, 5, 8, 2, 27, 1, 5,

    11, 22, 74, 80, 3, 54, 7, 600, 24, 39, 25, 11, 21, 574, 2, 29, 3, 4, 61, 4, 1, 4, 2, 28, 1, 35, 1, 1, 1, 4, 3, 1, 1,

    7, 2, 52, 3, 24, 1, 14, 1, 11, 1, 1, 3, 893, 3, 5, 171, 47, 1, 47, 1, 16, 1, 13, 2, 107, 14, 45, 10, 54, 9, 1, 16,

    23, 9, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 1, 7, 33, 49, 79, 26, 1, 89, 12, 214, 26, 12, 4, 64, 1, 86, 4, 101, 5,

    41, 3, 94, 1, 40, 8, 36, 12, 47, 1, 36, 12, 175, 1, 6838, 10, 20996, 60, 1165, 3, 55, 57, 300, 20, 32, 2, 13, 4, 1,

    10, 26, 104, 141, 110, 49, 20, 56, 8, 69, 9, 12, 38, 84, 11, 1, 160, 55, 9, 14, 2, 10, 2, 4, 416, 11172, 8540, 302,

    2, 59, 5, 106, 38, 7, 12, 5, 5, 26, 1, 5, 1, 1, 1, 2, 1, 2, 1, 108, 33, 365, 16, 64, 2, 54, 40, 14, 2, 26, 22, 35,

    1, 19, 1, 4, 4, 5, 1, 135, 2, 1, 1, 190, 3, 6, 2, 6, 2, 6, 2, 3, 3, 7, 1, 7, 10, 5, 2, 12, 1, 26, 1, 19, 1, 2, 1,

    15, 2, 14, 34, 123, 5, 3, 4, 45, 3, 84, 5, 12, 52, 45, 131, 29, 3, 49, 47, 31, 1, 4, 12, 27, 53, 30, 1, 37, 4, 14,

    42, 158, 2, 10, 854, 6, 2, 1, 1, 44, 1, 2, 3, 1, 2, 1, 192, 26, 5, 27, 5, 1, 192, 4, 1, 2, 5, 8, 1, 3, 1, 27, 4, 3,

    4, 9, 8, 9, 5543, 879, 145, 99, 13, 4, 43916, 246, 10, 39, 2, 60, 5, 3, 6, 8, 8, 2, 7, 30, 4, 48, 34, 66, 3, 1, 186,

    87, 9, 18, 142, 85, 1, 71, 1, 2, 2, 1, 2, 2, 2, 4, 1, 12, 1, 1, 1, 7, 1, 65, 1, 4, 2, 8, 1, 7, 1, 28, 1, 4, 1, 5, 1,

    1, 3, 7, 1, 340, 2, 292, 2, 50, 6144, 44, 4, 100, 3948, 42711, 20777, 542, 722403, 1, 30, 96, 128, 240, 0, 0

 

 

 

 

void compress(

    char const *filename )

    // Initialize the blocks' error to a ridiculously high number.

    for ( int y = 0; y < blocks_in_y; ++y )

        for ( int x = 0; x < blocks_in_x; ++x )

            blocks[ y ][ x ].error = 0x7fffffffffffffffLL;

 

    // Grab the source (range) image.

    Image range( filename );

    range.type( TrueColorType );

    range.matte( true );

    range.backgroundColor( Color( 0, 0, 0, QuantumRange ) );

    Geometry range_size = range.size();

    Pixels range_view( range );

 

    // Save the image size data for encoding later.

    image_width = range_size.width();

    image_height = range_size.height();

 

    // Try 16 different orientations for the downsampled image: four different 45 degree angles,

    // either flipped horizontally or not, and flipped vertically or not.  These are the domains.

    // We'll search these for matches to the blocks in the range.  (The 45 degree angle versions are

    // unorthodox, but help a *lot* for this image size and are only two more bits per block.)

    for ( int orientation = 0; orientation < 16; ++orientation )

    {

        Image domain( range );

        domain.zoom( "50%" );

        if ( orientation & 1 )

            domain.flip();

        if ( orientation & 2 )

            domain.flop();

        domain.rotate( orientation / 4 * 45 );

        Geometry domain_size = domain.size();

        Pixels domain_view( domain );

 

        // For each of the range blocks, we'll look for good matches in the current domain image.

        for ( int range_y = 0; range_y < blocks_in_y; ++range_y )

        {

            cout << ( orientation * blocks_in_y + range_y ) << "/" << ( 16 * blocks_in_y ) << "\r" << flush;

            int range_top = range_size.height() * range_y / blocks_in_y;

            int block_height = range_size.height() * ( range_y + 1) / blocks_in_y - range_top;

            for ( int range_x = 0; range_x < blocks_in_x; ++range_x )

            {

                int range_left = range_size.width() * range_x / blocks_in_x;

                int block_width = range_size.width() * ( range_x + 1) / blocks_in_x - range_left;

                int area = block_width * block_height;

 

                // Make note of the average color in this range block.

                const PixelPacket *range_pixels = range_view.getConst( range_left, range_top, block_width, block_height );

                int range_red = 0;

                int range_green = 0;

                int range_blue = 0;

                for ( int index = 0; index < area; ++index, ++range_pixels )

                {

                    range_red += range_pixels->red;

                    range_green += range_pixels->green;

                    range_blue += range_pixels->blue;

                }

 

                // Now we'll search for pieces of the domain that look like good matches for the

                // current range block.

                for ( int domain_y = 0; domain_y < steps_in_y; ++domain_y )

                {

                    int domain_top = ( domain_size.height() - block_height ) * domain_y / steps_in_y;

                    for ( int domain_x = 0; domain_x < steps_in_x; ++domain_x )

                    {

                        int domain_left = ( domain_size.width() - block_width ) * domain_x / steps_in_x;

 

                        // Compute the average color in this domain block.  If we have transparent

                        // pixels, we've hit the transparent corners of the image generated by

                        // rotations at 45 degree angles.  We'll reject these since they produce

                        // weird solid colors in the output.

                        const PixelPacket *domain_pixels = domain_view.getConst( domain_left, domain_top, block_width, block_height );

                        int domain_red = 0;

                        int domain_green = 0;

                        int domain_blue = 0;

                        bool corner = false;

                        for ( int index = 0; index < area; ++index, ++domain_pixels )

                        {

                            if ( domain_pixels->opacity > QuantumRange / 2 )

                            {

                                corner = true;

                                break;

                            }

                            domain_red += domain_pixels->red;

                            domain_green += domain_pixels->green;

                            domain_blue += domain_pixels->blue;

                        }

                        if ( corner )

                            continue;

 

                        // Storing a contrast and brightness adjustment for each each color

                        // component takes too much space.  Instead, we find a constant color, that

                        // when blended with the domain block comes as close as possible to the

                        // range block's color.

                        int red_shift = ( ( color_weight_a + color_weight_b ) * range_red - color_weight_b * domain_red ) / ( area * color_weight_a );

                        int green_shift = ( ( color_weight_a + color_weight_b ) * range_green - color_weight_b * domain_green ) / ( area * color_weight_a );

                        int blue_shift = ( ( color_weight_a + color_weight_b ) * range_blue - color_weight_b * domain_blue ) / ( area * color_weight_a );

 

                        // Then we heavily quantize that color down to a few steps.  It's an

                        // extremely limited palette but when blended with the domain blocks the

                        // color fidelity can be surprising good.

                        int red_bits = ( red_shift * ( steps_in_red - 1 ) + QuantumRange / 2 ) / QuantumRange;

                        int green_bits = ( green_shift * ( steps_in_green - 1 ) + QuantumRange / 2 ) / QuantumRange;

                        int blue_bits = ( blue_shift * ( steps_in_blue - 1 ) + QuantumRange / 2 ) / QuantumRange;

                        red_bits = min( steps_in_red - 1, max( 0, red_bits ) );

                        green_bits = min( steps_in_green - 1, max( 0, green_bits ) );

                        blue_bits = min( steps_in_blue - 1, max( 0, blue_bits ) );

 

                        // Now, compute the total RMS error between all of the pixels in the range

                        // block and the color-blended domain block.

                        int quantized_red = red_bits * QuantumRange / ( steps_in_red - 1 );

                        int quantized_green = green_bits * QuantumRange / ( steps_in_green - 1 );

                        int quantized_blue = blue_bits * QuantumRange / ( steps_in_blue - 1 );

                        range_pixels = range_view.getConst( range_left, range_top, block_width, block_height );

                        domain_pixels = domain_view.getConst( domain_left, domain_top, block_width, block_height );

                        long long int error = 0;

                        for ( int index = 0; index < area; ++index, ++range_pixels, ++domain_pixels )

                        {

                            long long int red_error = range_pixels->red - ( quantized_red * color_weight_a + domain_pixels->red * color_weight_b ) / ( color_weight_a + color_weight_b );

                            long long int green_error = range_pixels->green - ( quantized_green * color_weight_a + domain_pixels->green * color_weight_b ) / ( color_weight_a + color_weight_b );

                            long long int blue_error = range_pixels->blue - ( quantized_blue * color_weight_a + domain_pixels->blue * color_weight_b ) / ( color_weight_a + color_weight_b );

                            error += red_error * red_error + green_error * green_error + blue_error * blue_error;

                        }

 

                        // Is it out best match yet?

                        if ( error < blocks[ range_y ][ range_x ].error )

                        {

                            blocks[ range_y ][ range_x ].orientation = orientation;

                            blocks[ range_y ][ range_x ].x = domain_x;

                            blocks[ range_y ][ range_x ].y = domain_y;

                            blocks[ range_y ][ range_x ].red = red_bits;

                            blocks[ range_y ][ range_x ].green = green_bits;

                            blocks[ range_y ][ range_x ].blue = blue_bits;

                            blocks[ range_y ][ range_x ].error = error;

                        }

 

                    }

                }

            }

        }

    }

 

void decompress(

    char const *filename )

    // Start out with a black range image.

    Image range( Geometry( image_width, image_height ), Color( "black" ) );

    range.backgroundColor( Color( "black" ) );

 

    // Then go for a fixed number of iterations.  Saving the image after each iteration produces a

    // fun progressive reveal of the decompressed image.

    for ( int iteration = 0; iteration < iterations; ++iteration )

    {

        cout << iteration << "/" << iterations << "\r" << flush;

 

        // Precompute the downsampling and all of the different orientations of the range image.

        Image orientations[ 16 ];

        orientations[ 0 ] = range;

        orientations[ 0 ].zoom( "50%" );

        for ( int orientation = 1; orientation < 16; ++orientation )

        {

            orientations[ orientation ] = orientations[ 0 ];

            if ( orientation & 1 )

                orientations[ orientation ].flip();

            if ( orientation & 2 )

                orientations[ orientation ].flop();

            orientations[ orientation ].rotate( orientation / 4 * 45 );

        }

 

        // Then loop over all of the range blocks, and replace each with a copy of the domain block

        // that our compression data tells us to.  We also do the color blending as part of this.

        for ( int range_y = 0; range_y < blocks_in_y; ++range_y )

        {

            int range_top = image_height * range_y / blocks_in_y;

            int block_height = image_height * ( range_y + 1) / blocks_in_y - range_top;

            for ( int range_x = 0; range_x < blocks_in_x; ++range_x )

            {

                int range_left = image_width * range_x / blocks_in_x;

                int block_width = image_width * ( range_x + 1) / blocks_in_x - range_left;

 

                block &current = blocks[ range_y ][ range_x ];

 

                Image domain = orientations[ current.orientation ];

                Geometry domain_size = domain.size();

 

                int domain_top = ( domain_size.height() - block_height ) * current.y / steps_in_y;

                int domain_left = ( domain_size.width() - block_width ) * current.x / steps_in_x;

                domain.crop( Geometry( block_width, block_height, domain_left, domain_top ) );

 

                int quantized_red = current.red * QuantumRange / ( steps_in_red - 1 );

                int quantized_green = current.green * QuantumRange / ( steps_in_green - 1 );

                int quantized_blue = current.blue * QuantumRange / ( steps_in_blue - 1 );

                domain.colorize( 100 * color_weight_a / ( color_weight_a + color_weight_b ),

                                 Color( quantized_red, quantized_green, quantized_blue ) );

 

                range.draw( DrawableCompositeImage( range_left, range_top, domain ) );

            }

        }

 

    }

 

    range.write( filename );

 

void encode(

    char const *filename )

    // For encoding, we just take all the information stored in the blocks structure, along with the

    // image size, and turn it into a huge number.  This is like using a variable base.

    mpz_class number = 0;

    for ( int y = 0; y < blocks_in_y; ++y )

        for ( int x = 0; x < blocks_in_x; ++x )

        {

            block &current = blocks[ y ][ x ];

            int part = current.orientation;

            part = part * steps_in_x + current.x;

            part = part * steps_in_y + current.y;

            part = part * steps_in_red + current.red;

            part = part * steps_in_green + current.green;

            part = part * steps_in_blue + current.blue;

            number *= 16 * steps_in_x * steps_in_y * steps_in_red * steps_in_green * steps_in_blue;

            number += part;

        }

    number = number * maximum_width + image_width;

    number = number * maximum_height + image_height;

 

    // Next, we convert that to characters.  We essentially just convert the giant number into the

    // base of how ever many characters we have available in our encoding.

    int count = 0;

    ofstream out( filename, ios::out | ios::binary );

    while ( number != 0 )

    {

        int value = static_cast< mpz_class >( number % number_assigned ).get_si();

        number /= number_assigned;

 

        // Lookup the character that this value maps to.

        int character = 0;

        for ( int index = 0; ; index += 2 )

        {

            character += codes[ index ] + min( value, codes[ index + 1 ] );

            if ( value == codes[ index + 1 ] )

                character += codes[ index + 2 ];

            value -= min( value, codes[ index + 1 ] );

            if ( !value )

                break;

        }

 

        // And UTF-8 encode that and output it.

        if ( character < 0x80 )

            out << static_cast< char >( character );

        else if ( character < 0x800 )

            out << static_cast< char >( 0xc0 | character >>  6 & 0x1f )

                << static_cast< char >( 0x80 | character >>  0 & 0x3f );

        else if ( character < 0x10000 )

            out << static_cast< char >( 0xe0 | character >> 12 & 0x0f )

                << static_cast< char >( 0x80 | character >>  6 & 0x3f )

                << static_cast< char >( 0x80 | character >>  0 & 0x3f );

        else if ( character < 0x200000 )

            out << static_cast< char >( 0xf0 | character >> 18 & 0x07 )

                << static_cast< char >( 0x80 | character >> 12 & 0x3f )

                << static_cast< char >( 0x80 | character >>  6 & 0x3f )

                << static_cast< char >( 0x80 | character >>  0 & 0x3f );

        ++count;

    }

    cout << "Characters written: " << count << endl;

 

void decode(

    char const *filename )

    // Here we build back that giant number.  Again, it's deriving a number in the base of however

    // many characters there are in the character set we're using.

    ifstream in( filename, ios::out | ios::binary );

    mpz_class number = 0;

    mpz_class place = 1;

    for ( ; ; )

    {

        // Read in a UTF-8 character

        int character = in.get();

        if ( character == EOF )

            break;

        if ( ( character & 0xe0 ) == 0xc0 )

            character = ( ( character & 0x1f ) <<  6 |

                          in.get()    & 0x3f );

        else if ( ( character & 0xf0 ) == 0xe0 )

            character = ( ( character & 0x0f ) << 12 |

                          ( in.get()  & 0x3f ) <<  6 |

                          in.get()    & 0x3f );

        else if ( ( character & 0xf8 ) == 0xf0 )

            character = ( ( character & 0x07 ) << 18 |

                          ( in.get()  & 0x3f )  << 12 |

                          ( in.get()  & 0x3f )  <<  6 |

                          in.get()    & 0x3f );

 

        // And convert it back to a value.

        int value = 0;

        for ( int index = 0; character; index += 2 )

        {

            character -= codes[ index ];

            value += min( character, codes[ index + 1 ] );

            character -= min( character, codes[ index + 1 ] );

        }

 

        // We're reading back in order from least to most significant.

        number += value * place;

        place *= number_assigned;

    }

 

    // Now, we do the conversion back from that giant number to fill the image size and the block

    // data.  This is all just the reverse order of the encoding of this into the giant number.

    image_height = static_cast< mpz_class >( number % maximum_height ).get_si();

    number /= maximum_height;

    image_width = static_cast< mpz_class >( number % maximum_width ).get_si();

    number /= maximum_width;

    for ( int y = blocks_in_y - 1; y >= 0; --y )

        for ( int x = blocks_in_x - 1; x >= 0; --x )

        {

            block &current = blocks[ y ][ x ];

            current.blue = static_cast< mpz_class >( number % steps_in_blue ).get_si();

            number /= steps_in_blue;

            current.green = static_cast< mpz_class >( number % steps_in_green ).get_si();

            number /= steps_in_green;

            current.red = static_cast< mpz_class >( number % steps_in_red ).get_si();

            number /= steps_in_red;

            current.y = static_cast< mpz_class >( number % steps_in_y ).get_si();

            number /= steps_in_y;

            current.x = static_cast< mpz_class >( number % steps_in_x ).get_si();

            number /= steps_in_x;

            current.orientation = static_cast< mpz_class >( number % 16 ).get_si();

            number /= 16;

        }

 

int main(

    int argc,

    char **argv )

    if ( !strcmp( argv[ 1 ], "encode" ) )

    {

        compress( argv[ 2 ] );

        encode( argv[ 3 ] );

    }

    else

    {

        decode( argv[ 2 ] );

        decompress( argv[ 3 ] );

    }

    return 0;