If you need a freeware High Dynamic Range Imaging Software then you can try out Picturenaut. Actually HDRI is a set of techniques which allows you to get a greater dynamic range of exposures than normal digital imaging techniques. It can be used to accurately represent the wide range of intensity levels found in real scenes. Picturenaut is a freeware High Dynamic Range Imaging (HDRI) software which provides automatic image alignment, exposure correction, color balancing, noise level compensation and automatic derivation of the camera curve from the source images.
With the help of Picturenaut you can easily make HDR images. With Picturenaut you can get all the convenient features like exposure detection from EXIF data and automatic image alignment. Moreover Picturenaut’s multi-threaded architecture makes it one of the fastest tone mapper. Picturenaut can also read the EXIF metadata and ICC profiles from the images and you can manually edit the aperture, shutter speed, EV offset and many others.
The best thing about Picturenaut is that many of the plugins developed for HDRShop can be used here. You have Gaussian Motion Blur, Absolute HDR Calibration, Diffuse SH: spherical harmonics, Median Cut: light source extraction, MyFilter: custom convolution kernels, FakeHDRI: stretch out LDR pixel values and many more. Picturenaut supports PFM (Portable Float Map), HDR (Radiance), EXR (OpenEXR), TIFF (32-bit Floating Point), TIFF (LogLuv), LDR, JPEG, TIFF(RGB) and TGA.