| See the main README file for basic instructions on compiling and running |
| the programs. See http://www.libpng.org/pub/png/pngbook.html for further |
| information and links to the source code, and Chapters 13-15 of the book |
| for detailed discussion of the three programs. |
| |
| Since the two viewers, rpng and rpng2, are both designed to write infor- |
| mation to the console (i.e., a DOS-window command line) while displaying |
| the image in a graphical window--and since I haven't yet figured out how |
| to do that under Windows--here are the usage screens for the two programs: |
| |
| |
| rpng-win 1.02 of 19 March 2000: Simple PNG Viewer for Windows |
| Compiled with libpng 1.0.5; using libpng 1.0.5. |
| Compiled with zlib 1.1.3; using zlib 1.1.3. |
| |
| Usage: rpng-win [-gamma exp] [-bgcolor bg] file.png |
| exp transfer-function exponent (``gamma'') of the display |
| system in floating-point format (e.g., ``2.2''); equal |
| to the product of the lookup-table exponent (varies) |
| and the CRT exponent (usually 2.2); must be positive |
| bg desired background color in 7-character hex RGB format |
| (e.g., ``#ff7f00'' for orange: same as HTML colors); |
| used with transparent images |
| |
| Press Q, Esc or mouse button 1 after image is displayed to quit. |
| |
| |
| rpng2-win 1.04 of 19 March 2000: Progressive PNG Viewer for Windows |
| Compiled with libpng 1.0.5; using libpng 1.0.5. |
| Compiled with zlib 1.1.3; using zlib 1.1.3. |
| |
| Usage: rpng2-win [-gamma exp] [-bgcolor bg | -bgpat pat] [-timing] file.png |
| |
| exp transfer-function exponent (``gamma'') of the display |
| system in floating-point format (e.g., ``2.2''); equal |
| to the product of the lookup-table exponent (varies) |
| and the CRT exponent (usually 2.2); must be positive |
| bg desired background color in 7-character hex RGB format |
| (e.g., ``#ff7f00'' for orange: same as HTML colors); |
| used with transparent images; overrides -bgpat |
| pat desired background pattern number (1-16); used with |
| transparent images; overrides -bgcolor |
| -timing enables delay for every block read, to simulate modem |
| download of image (~36 Kbps) |
| |
| Press Q, Esc or mouse button 1 after image is displayed to quit. |
| |
| |
| The usage screen for the third (non-windowed) program, wpng, can be seen |
| simply by invoking it without any parameters (``wpng''). |
| |
| Greg Roelofs |
| 19 March 2000 |
