How to get RGB values of every pixel in BMP by using Qt?

Question

I need to write simple program which can open any BMP file, use RLE compression, save result, open it again and decompress file to normal BMP. Problem is I do not know how to get RGB components of file. There are so many version of BMP standard. I know how to open it in Qt, how to create, and how load in to widget, but I can not find a way to read file information and headers in one bytearray and RGB values in another. Is there in Qt some methods to do that?

Answer 1

QImage will load the image for you. BMP is one of the supported formats. You shouldn't care about the BMP standard used since Qt handles it internally.

You can access the RGB value of any pixel using the pixel method of QImage.

QImage image;
image.load("myimage.bmp");
QVector<QRgb> imageRGBValues;

for (unsigned i=0; i<image.width(); ++i)
{
   for (unsigned j=0; j<image.height(); ++j)
      imageRGBValues.push_back(image.pixel(i,j));
}