i want rgb details from .bmp

[swetha.bsharma]

Hello,

I am reading the values of r,g,b from a .bmp file.

 ifstream fin;

	fin.open("deer256.bmp",ios::binary);

	int height,width;
	 char *imageByte;
	int index=0;

	if(fin!=NULL)
	{
		fin.seekg(18);
		fin.read((char*)&width,4);
		fin.read((char*)&height,4);

		cout<<height<<endl;
		cout<<width<<endl;

		imageByte = new char;

	      imageByte = new unsigned char[height*width];

		while(fin.good())
		{
			fin.read(imageByte,1);
			cout<<(int)imageByte;
			++index;
		}
	}
	else
	{
		cout<<"image file not open\n";
	}

The height and width are read perfectly but the values in imageByte are junk values. Is something wrong?

rgds
swetha

[Zachm]

I think you are not reading the file correctly.
See this link on BMP format. Take a look at the source code provided in the page.

[JohnyDog]

Also, you're writing all the chars to same location.(imageByte[0]) Change this:

	fin.read(imageByte+index,1);

[golanshahar]

Hello,

I am reading the values of r,g,b from a .bmp file.

 ifstream fin;

	fin.open("deer256.bmp",ios::binary);

	int height,width;
	 char *imageByte;
	int index=0;

	if(fin!=NULL)
	{
		fin.seekg(18);
		fin.read((char*)&width,4);
		fin.read((char*)&height,4);

		cout<<height<<endl;
		cout<<width<<endl;

		imageByte = new char;

	      imageByte = new unsigned char[height*width];

		while(fin.good())
		{
			fin.read(imageByte,1);
			cout<<(int)imageByte;
			++index;
		}
	}
	else
	{
		cout<<"image file not open\n";
	}

The height and width are read perfectly but the values in imageByte are junk values. Is something wrong?

rgds
swetha

Why you are not using ::LoadImage() and ::GetBitmapBits() or ::GetDiBits() ?

Cheers

[djai]

Use CImage class and create a object of it use like this

CImage imgoriginal;
imgOriginal.Load(dlg.GetFileName());
COLORREF pixel;
int maxY = imgOriginal.GetHeight(), maxX = imgOriginal.GetWidth();
byte r,g,b,avg;
for (int x=0; x<maxX; x++) {
for (int y=0; y<maxY; y++) {
pixel = imgOriginal.GetPixel(x,y);
r = GetRValue(pixel);
g = GetGValue(pixel);
b = GetBValue(pixel);
now you can get RGB values from it