bitmap speichern
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hallo!
ich hab problems bei abspeichern einer bitmap, ich übergebe der methode SetPixel col...dh R,G,B sind immer gleich und haben den wert col! dh ich werde graubilder speichern...
hab auch schon verucht R,G,B in ein array zu tun hat aber auch nicht geklappt...
hab mir das BMP Format noch mal angeschaut:
http://www.wotsit.org/search.asp?s=graphicsvielleicht kann jemand mir da weiter helfen...im endeffekt will ich in einer bitmap die einzelnen pixel setzen...mit dem offset muss man noch aufpassen hab ich wo gelesen
cu
#ifndef Bitmap_H #define Bitmap_H #include <stdio.h> #include <string.h> #include <string> #include <iostream> #include <math.h> #include <ctime> #include <fstream> using namespace std; #include "Exception.h" class Bitmap { private: struct BMPInfoHeader { unsigned long nSize; long nWidth; long nHeight; unsigned short nPlanes; unsigned short nBitCount; unsigned long nCompression; unsigned long nSizeImage; long nXPelsPerMeter; long nYPelsPerMeter; unsigned long nClearUsed; unsigned long nClearImportant; }; struct BMPFileHeader { unsigned short nType; UINT nSize; unsigned short Reserved1; unsigned short Reserved2; UINT nOffBits; }; ofstream stream; BMPInfoHeader infoheader; BMPFileHeader fileheader; public: Bitmap(long Width, long Height) { // open stream stream.open ("PerlinNoise.bmp", ios::binary); // fill the headers with image data fileheader.nType = 0x4D42; fileheader.nSize = sizeof (BMPInfoHeader) + sizeof (BMPFileHeader) + 3 * Width * Height; fileheader.Reserved1 = 0; fileheader.Reserved2 = 0; fileheader.nOffBits = sizeof (BMPInfoHeader) + sizeof (BMPFileHeader); infoheader.nSize = sizeof (BMPInfoHeader); infoheader.nWidth = Width; infoheader.nHeight = Height; infoheader.nPlanes = 1; infoheader.nBitCount = 24; infoheader.nCompression = 0; infoheader.nSizeImage = Width * Height; infoheader.nXPelsPerMeter = 2835; infoheader.nYPelsPerMeter = 2835; infoheader.nClearUsed = 0; infoheader.nClearImportant = 0; stream.write (reinterpret_cast <char*> (&fileheader), sizeof (fileheader)); stream.write (reinterpret_cast <char*> (&infoheader), sizeof (infoheader)); } ~Bitmap() { stream.close(); } void SetPixel(int line, int pos, int col); }; void Bitmap::SetPixel(int pos, int line, int col) { stream << col; // R stream << col; // G stream << col; // B } #endif
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Was genau hat nicht geklappt?
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ich brauch noch ein RGBQUAD array und
Color-inex array
mit welchen daten befülle ich die?cu
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hi leute! ich hab nun mal mit hilfe eines freundes die methode setpixel neu geschrieben....
class Bitmap { private: struct BMPInfoHeader { unsigned long nSize; long nWidth; long nHeight; unsigned short nPlanes; unsigned short nBitCount; unsigned long nCompression; unsigned long nSizeImage; long nXPelsPerMeter; long nYPelsPerMeter; unsigned long nClearUsed; unsigned long nClearImportant; }; struct BMPFileHeader { unsigned short nType; UINT nSize; unsigned short Reserved1; unsigned short Reserved2; UINT nOffBits; }; struct Color { unsigned char byRed; unsigned char byGreen; unsigned char byBlue; }; ofstream m_stream; BMPInfoHeader m_infoheader; BMPFileHeader m_fileheader; int m_nWidth; int m_nHeight; Color* m_pPixeldata; public: Bitmap(int nWidth, int nHeight); void SetPixel(int x, int y, Color col); void SetPixel(int x, int y, int red, int green, int blue); void SaveBitmap(string filename); }; Bitmap::Bitmap(int nWidth, int nHeight) { m_pPixeldata = new Color[nWidth*nHeight]; this->m_nWidth = nWidth; this->m_nHeight = nHeight; } void Bitmap::SetPixel(int x, int y, Color col) { if((x>=0 && x <this->m_nWidth) && (y>=0 && y <this->m_nHeight)) this->m_pPixeldata[x+y*this->m_nWidth] = col; } void Bitmap::SetPixel(int x, int y, int red, int green, int blue) { if((x>=0 && x <this->m_nWidth) && (y>=0 && y <this->m_nHeight)) { Color col; col.byRed = static_cast<char>(blue); col.byGreen = static_cast<char>(red); col.byBlue = static_cast<char>(green); this->m_pPixeldata[x+y*this->m_nWidth] = col; } } void Bitmap::SaveBitmap(string filename) { int nLineWidth = this->m_nWidth; while(nLineWidth%4!=0) nLineWidth++; unsigned char ucDummy = 0; memset(&m_fileheader,0,sizeof(m_fileheader)); // fill the he aders with image data m_fileheader.nType=0x4d42;//"BM" m_fileheader.nSize=(unsigned int)(sizeof(BMPFileHeader) + sizeof(BMPInfoHeader) + (((this->m_nWidth*3+3)&0xFFFFFC)*this->m_nHeight)); m_fileheader.nOffBits=sizeof(BMPFileHeader)+sizeof(BMPInfoHeader); memset(&m_infoheader,0,sizeof(m_infoheader)); m_infoheader.nSize=sizeof(BMPInfoHeader); m_infoheader.nWidth=this->m_nWidth; m_infoheader.nHeight=this->m_nHeight; m_infoheader.nPlanes=1; m_infoheader.nBitCount=24; m_infoheader.nCompression=BI_RGB; m_infoheader.nXPelsPerMeter=2834;//72 DPI m_infoheader.nYPelsPerMeter=2834;//72 DPI m_infoheader.nSizeImage=this->m_nWidth*this->m_nHeight*3; m_infoheader.nClearUsed = 0; m_infoheader.nClearImportant = 0; this->m_stream.open(filename.c_str(), ios::binary); m_stream.write (reinterpret_cast <char*> (&m_fileheader), sizeof (BMPFileHeader)); m_stream.write (reinterpret_cast <char*> (&m_infoheader), sizeof (BMPInfoHeader)); for(int y = 0; y < this->m_nHeight; y++) { for(int x = 0; x < nLineWidth; x++) { // writing fillbytes? if(x >= this->m_nWidth) { m_stream.write (reinterpret_cast <char*> (&ucDummy), 1); } else { // write colordata m_stream.write (reinterpret_cast <char*> (&this->m_pPixeldata[x+y*this->m_nWidth].byBlue), 1); m_stream.write (reinterpret_cast <char*> (&this->m_pPixeldata[x+y*this->m_nWidth].byGreen), 1); m_stream.write (reinterpret_cast <char*> (&this->m_pPixeldata[x+y*this->m_nWidth].byRed), 1); x+=2; // 3 bytes written already! -> not only one } } } this->m_stream.close(); } #endifmir fällt gerade auf, dass der fileheader struktur 2 bytes größer ist, als sie sein sollte die sollte 14 bytes groß sein, ist aber 16 bytes groß........
warum liegt das...? die bitmap wird daher nicht korrekt dargestellt;-(
vielleicht weiß jemand woran es liegt!?cu