Converting DPX and EXR to RGB in C++

[CCLin]

I've compiled Imagemagick 6.6.1 with HDRI and exr enabled.
I'm also developing my application with generated DLLs for converting image formats.
Now I encounter a problem converting DPX and EXR to BMP.
For EXR files, my C++ codes are as follows:

Code: Select all

try {   
	src_image.read("image.exr");
	width = src_image.columns();
	height = src_image.rows();
}catch( Exception &error_ ) //not an image file
{
	continue;
} 
src_image.modifyImage();
src_image.type(TrueColorType);
src_image.gamma(2.2);
pixel = src_image.getPixels(0,0,width,height);

for(int y=0; y<height; y++)
{
    for(int x=0; x<width; x++)
    {
	PixelPacket *pixel_rgb = pixel + y*width+x;
	input_rgb[y*width*3 + 3*x + 0] = (pixel_rgb->blue); //B
	input_rgb[y*width*3 + 3*x + 1] = (pixel_rgb->green); //G
	input_rgb[y*width*3 + 3*x + 2] = (pixel_rgb->red); //R
    }
}

After writing the rgb buffer to a bmp file, the content is a mess.
How do I retrieve the pixels in RGB from exr file? I think I can set the color depth (e.g. RGB888) but I don't know how.
Please help...

For DPX files, the codes to convert DPX to BMP are exactly the same as above, the except the file name is "my_image.dpx".
However, the output bmp file looks like the red and blue are swapped. I have to swapped red and blue in codes to make it right.
Please also advise what is going wrong.

Thank you!