Probleme dans la lecture d’un bmp
Code:
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| // bmp1.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <windows.h>
#include <fstream.h>
class CRaster {
public:
int Width,Height; // Dimensions
int BPP; // Bits Per Pixel.
char * Raster; // Bits of the Image.
RGBQUAD * Palette; // RGB Palette for the image.
int BytesPerRow; // Row Width (in bytes).
BITMAPINFO * pbmi; // BITMAPINFO structure
// Member functions (defined later):
int LoadBMP (char * szFile);
int GDIPaint (HDC hdc,int x,int y);
};
int CRaster::LoadBMP (char * szFile)
{
BITMAPFILEHEADER bmfh;
BITMAPINFOHEADER bmih;
// Open file.
ifstream bmpfile (szFile , ios::in | ios::binary);
if (! bmpfile.is_open()){cout<<"Erreur"; return 1; } // Error opening file
// Load bitmap fileheader & infoheader
bmpfile.read ((char*)&bmfh,sizeof (BITMAPFILEHEADER));
bmpfile.read ((char*)&bmih,sizeof (BITMAPINFOHEADER));
// Check filetype signature
if (bmfh.bfType!='MB') return 2; // File is not BMP
// Assign some short variables:
BPP=bmih.biBitCount;
Width=bmih.biWidth;
Height= (bmih.biHeight>0) ? bmih.biHeight : -bmih.biHeight; // absoulte value
BytesPerRow = Width * BPP / 8;
BytesPerRow += (4-BytesPerRow%4) % 4; // int alignment
// If BPP aren't 24, load Palette:
if (BPP==24) pbmi=(BITMAPINFO*)new char [sizeof(BITMAPINFO)];
else
{
pbmi=(BITMAPINFO*) new char[sizeof(BITMAPINFOHEADER)+(1<<BPP)*sizeof(RGBQUAD)];
Palette=(RGBQUAD*)((char*)pbmi+sizeof(BITMAPINFOHEADER));
bmpfile.read ((char*)Palette,sizeof (RGBQUAD) * (1<<BPP));
}
pbmi->bmiHeader=bmih;
// Load Raster
bmpfile.seekg (bmfh.bfOffBits,ios::beg);
Raster= new char[BytesPerRow*Height];
// (if height is positive the bmp is bottom-up, read it reversed)
if (bmih.biHeight>0)
for (int n=Height-1;n>=0;n--)
bmpfile.read (Raster+BytesPerRow*n,BytesPerRow);
else
bmpfile.read (Raster,BytesPerRow*Height);
// so, we always have a up-bottom raster (that is negative height for windows):
pbmi->bmiHeader.biHeight=-Height;
bmpfile.close();
return 0;
}
int main(void){
CRaster a;
a.LoadBMP("d:\\test.bmp");
return 0;
} |
