GSHHG Project

What a great name - A Global Self-consistent, Hierarchical, High-resolution Geography Database

For the original source data see http://www.soest.hawaii.edu/pwessel/gshhg/, and perhaps updates.

For another project related to flight planning I needed to be able to extract a bounding box of the shoreline, and so this small project was born.

The final executable is gshhg.exe, Running it with -? will give details of its usage. The area extracted can be written to an 'xg' file, which can be viewed by a PolyView2D app, which is part of this repo - https://gitlab.com/fgtools/osm2xg.

But then the porject expanded, exploring and testing reading/writing various image files.

Prerequisites:

git - http://git-scm.com/downloads
cmake - http://www.cmake.org/download/
Native build tools to suit genertor used.
PNG (and ZLIB) - Optionals. Only some tools require this.

Building:

This project uses the cmake build file generator.

In Unix/Linux

cd build
cmake ..
make

In Windows

cd build
cmake ..
cmake --build . --config Release

The 'build' directory contains convenient build scripts - build-me.bat and build-me.sh - It should be relatively easy to modify these to suit your particular environment.

Of course the cmake GUI can also be used, setting the source directory, and the binary directory to the 'build' folder. And in Windows, the MSVC IDE can be used if this is the chosen generator.

Bitmap Tests (BMP)

bmp_utils - A bitmap utility library

A whole bunch of little utilities, all dealing with bitmaps.

bmp-test
bmp-1bit
bmp_io
Int2BMP
write-bmp1
write-bmp2

1. bmp-test

Test program for reading bitmap files. It accepts an input file and an output file on the command line. It will read and process the input file and dump an ASCII representation of the contents to the output file. The dump will consist of the color image and two masks. Missing parts will be indicated as such (BMP files have no masks and monochrome ICO/PTR files have no color data. In the color image, the dump will be a series of RGB values (in hexadecimal). In the masks, the dump will be represented by "." symbols representing zeros and "@" symbols representing ones.

This is a good example of crossplatfom bitmap handling, since no Windows API is used, and it defines all it own structures.

2. bmp-1bit

Generates a random 1000 x 1000 monchrome bitmap, again NOT using any Windows API. Only optional input is the name of the output random bitmap file.

Is just an example of how to generate a monochrome bitmap, from a randomly generate byte array, in a cross platform way.

3. bmp_io

This application does NOTHING! It is just some crossplatform Windows BMP functions. This the full list from bmp_io.hpp

bool bmp_byte_swap_get ( void );
void bmp_byte_swap_set ( bool value );

bool bmp_08_data_read ( ifstream &file_in, unsigned long int width, long int height, unsigned char *rarray );
void bmp_08_data_write ( ofstream &file_out, unsigned long int width, long int height, unsigned char *rarray );

bool bmp_24_data_read ( ifstream &file_in, unsigned long int width, long int height, unsigned char *rarray, unsigned char *garray, unsigned char *barray );
void bmp_24_data_write ( ofstream &file_out, unsigned long int width, long int height, unsigned char *rarray, unsigned char *garray, unsigned char *barray );

void bmp_header1_print ( unsigned short int filetype, unsigned long int filesize, unsigned short int reserved1, unsigned short int reserved2, unsigned long int bitmapoffset );
bool bmp_header1_read ( ifstream &file_in, unsigned short int *filetype, unsigned long int *filesize, unsigned long int *reserved1, unsigned short int *reserved2, unsigned long int *bitmapoffset );
void bmp_header1_write ( ofstream &file_out, unsigned short int filetype, unsigned long int filesize, unsigned long int reserved1, unsigned short int reserved2, unsigned long int bitmapoffset );

void bmp_header2_print ( unsigned long int size, unsigned long int width, long int height, unsigned short int planes, unsigned short int bitsperpixel, unsigned long int compression, unsigned long int sizeofbitmap, unsigned long int horzresolution, unsigned long int vertresolution, unsigned long int colorsused, unsigned long int colorsimportant );
bool bmp_header2_read ( ifstream &file_in, unsigned long int *size, unsigned long int *width, long int *height, unsigned short int *planes, unsigned short int *bitsperpixel, unsigned long int *compression, unsigned long int *sizeofbitmap, unsigned long int *horzresolution, unsigned long int *vertresolution, unsigned long int *colorsused, unsigned long int *colorsimportant );
void bmp_header2_write ( ofstream &file_out, unsigned long int size, unsigned long int width, long int height, unsigned short int planes, unsigned short int bitsperpixel, unsigned long int compression, unsigned long int sizeofbitmap, unsigned long int horzresolution, unsigned long int vertresolution, unsigned long int colorsused, unsigned long int colorsimportant );

void bmp_palette_print ( unsigned long int colorsused, unsigned char *rparray, unsigned char *gparray, unsigned char *bparray, unsigned char *aparray );
bool bmp_palette_read ( ifstream &file_in, unsigned long int colorsused, unsigned char *rparray, unsigned char *gparray, unsigned char *bparray, unsigned char *aparray );
void bmp_palette_write ( ofstream &file_out, unsigned long int colorsused, unsigned char *rparray, unsigned char *gparray, unsigned char *bparray, unsigned char *aparray );

bool bmp_print_test ( char *file_in_name );

bool bmp_read ( char *file_in_name, unsigned long int *width, long int *height, unsigned char **rarray, unsigned char **garray, unsigned char **barray );
bool bmp_read_test ( char *file_in_name );

bool bmp_08_write ( char *file_out_name, unsigned long int width, long int height, unsigned char *rarray, unsigned char *garray, unsigned char *barray );
bool bmp_08_write_test ( char *file_out_name );

bool bmp_24_write ( char *file_out_name, unsigned long int width, long int height, unsigned char *rarray, unsigned char *garray, unsigned char *barray );
bool bmp_24_write_test ( char *file_out_name );

bool long_int_read ( long int *long_int_val, ifstream &file_in );
void long_int_write ( long int long_int_val, ofstream &file_out );

bool u_long_int_read ( unsigned long int *u_long_int_val, ifstream &file_in );
void u_long_int_write ( unsigned long int u_long_int_val, ofstream &file_out );

bool u_short_int_read ( unsigned short int *u_short_int_val, ifstream &file_in );
void u_short_int_write ( unsigned short int u_short_int_val, ofstream &file_out );

Although the file has a C++ extension, there is not really anything that is really C++. Most, if not all functions could be extracted and quite easily be used in a C program.

The source is from : http://people.sc.fsu.edu/~jburkardt/cpp_src/bmp_io/bmp_io.html

The Licensing: This code is distributed under the GNU LGPL license. Asside from this main() added by me, it was last modified: 13 August 2007, with an earliest date of 26 February 2003

The original Author: John Burkardt, and my thanks to him for putting them together.

Of course it could be quite easily cast into a library to attach to your own app. The important thing is that it is quite crossplatform, having NO dependency on the windows GDI header files.

4. Int2BMP

Again a cross-platform bitmap implmentation, using a class to build the bitmap.

Will read the in_file as an array of integers, space separated, values range from INT32_MIN through INT32_MAX and write a bitmap file, in uncompressed BI_RGB format. The width and height of the image is assumed to be the sqrt of the total number of integers found in the input. A non-rectangular numbers of integers yield non-rectangular bitmaps (final scanline may be short) This may cause some .bmp parsers to fail; others may pad with 0's. For simplicity, this implementation attempts to render square bitmaps.

In essence is a SIMPLE example of converting an array of integers to a BMP See http://stackoverflow.com/questions/12200201/c-convert-text-file-of-integers-into-a-bitmap-image-file-in-bmp-format for the original code. And as pointed out in that post, this is close to converting a PPM file to a BMP file, and would not take much effort to modify it to do that.

5. write-bmp1

This program does nothing. Just contains sample code void write_bmp( int w, int h, char *file ) Again a cross-platform bitmap implmentation

6. write-bmp2

Like the above does practically nothing. It generates a random 512 x 256 3 color array, and if an output file name is given on the command line, will write a 24-bit RGB bitmap, using something similar to the above write_bmp service. Again a cross-platform bitmap implmentation

Targa Tests (TGA)

tga-test -

Portable PixMap (PPM) GrayMap (PGM) BitMap (PBM)

pgm-test -

Have FUN ;=))

Geoff.
20150407

; eof

geoffmcl/gshhg