No cameras produces floating-point data raw images (yet?), one may use (different) HDR-convertor software to create floating point images.
Regarding color3/color4:
- full-color images unpacked by LibRaw itself are (mostly) color4_image, you may use any full-color (not bayer) RAW file for that, for example Canon sRAW/mRAW CR2
- full-color images unpacked by 3rd-party decoders (Adobe DNG SDK, RawSpeed) are usually color3_image images. You may use the same sRAW/mRAW CR2 and RawSpeed decoder (via LibRaw)
No cameras produces floating-point data raw images (yet?), one may use (different) HDR-convertor software to create floating point images.
Regarding color3/color4:
- full-color images unpacked by LibRaw itself are (mostly) color4_image, you may use any full-color (not bayer) RAW file for that, for example Canon sRAW/mRAW CR2
- full-color images unpacked by 3rd-party decoders (Adobe DNG SDK, RawSpeed) are usually color3_image images. You may use the same sRAW/mRAW CR2 and RawSpeed decoder (via LibRaw)