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Object Based PNG decoder. Test Project.
Uses ZLIB for it's inflate. A compatible include can be found at http://www.powerbasic.com/support/do...les/PBZLIB.zip
The descustion thread can be found at 'Forum\Programming with Objects\PNG Decoder v0.1 (Descusion Thread)'
Uses ZLIB for it's inflate. A compatible include can be found at http://www.powerbasic.com/support/do...les/PBZLIB.zip
The descustion thread can be found at 'Forum\Programming with Objects\PNG Decoder v0.1 (Descusion Thread)'
Code:
'================================================================================= 'PNG Decoder Copyright (C) 2009 by Cory A Marshall 'See "Legal Stuff" for details ' 'PNG V1.2 specifcation can be found at http://www.libpng.org/pub/png/spec/1.2/PNG-Contents.html ' PUBLIC Object calls are ' CheckCrc Controls the checking of CRC values during chunk scanning. Both GET and SET supported. False is default (no checking). ' LoadPNG(File) Opens and loads a png's file into memory. ' CopyToBitMap(hBmp) Copy's the internal 64bit color image into a windows BitMap at 24bit color ' lHeight Returns the Height of the Image in pixels ' lWidth Returns the Width of the image in pixels ' ' PRIVATE Objects ' Create Sets up varibles and tables for use. ' Distroy Releases tables from memory ' CalcCRC(CRC, Buff) Updates the CRC value with the data that is in the buff string ' ScanChunks Looks inside the png file indexing each chunk. Logging location, size, type, and crc values ' LoadPalette Grabs the PLTE chunk info for indexed images ' GrayScalePalette(shades) Fills the palette with a grayscale for quick conversion from grayscale to 64bit color format ' LoadIHDR Grabs the info from the IHDR chunk ' UnFilter Undoes the line filtering used in the image preprocessing stage ' ConvertBuffToColor64(Buff, Buff2) Transforms the different color formats in PNG to 64Bit color format used internaly ' LoadIDAT Grabs the IDAT chunks and puts the togther then uncompresses and deinterlaces it. ' ' 'For best veiwing set TAB Size to 3, [Sed Settings of Indent to 0 (makes it same as tab)] . ' 'Legal Stuff ' ' This program is free software; you can redistribute it and/or modify ' it under the terms of the GNU General Public License as published by ' the Free Software Foundation; either version 3 of the License, or ' (at your option) any later version. ' ' This program is distributed in the hope that it will be useful, ' but WITHOUT ANY WARRANTY; without even the implied warranty of ' MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ' GNU General Public License for more details. ' ' You should have received a copy of the GNU General Public License ' along with this program; if not, write to the Free Software ' Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. ' ' Free Software Foundation, Inc. website is located at www.fsf.org ' a copy of the GNU General Public License is hosted at ' http://www.fsf.org/licensing/licenses/gpl-3.0.html '================================================================================= 'ZLIB libary for PNG's Deflate/Inflate Compression. 'ZLIB Website is located at http://www.zlib.net/ 'PBZLIB can be found at http://www.powerbasic.com/support/downloads/files/PBZLIB.zip