I've tried using image magic but it converts the image into a compressed format and most of the online conversion tools are also doing the same thing.
Is there some way i could achieve this in image magic or anywhere else?
Use the ImageMagick "-compress none" option to prevent compression, and use "-define bmp:format=bmp4" to force BMP4.0:
convert in.jpg -define bmp:format=bmp4 -compress none out.bmp
You can omit defining the bmp4 format because that's the currently the default BMP output format for ImageMagick anyhow.
See the ImageMagick documentation for the -compress and -define options.