IMSHOW = True

import h5py

# path to the HDF5 file
dirname = '/mnt/md0/captures/2019May09-rover/camera/'
fname = 'images.h5'

# open file for reading
f = h5py.File(dirname + fname, 'r')

# images from the port side camera are named 'port/XXXXXX'
# images from the starboard side camera are named 'star/XXXXXX'
#
# to view the names of all images from the port side camera:
# print(f['port'].keys())
#
# as an example, we load the images 'port/000500' and 'star/000500'
im_port = f['port/000500']
im_star = f['star/000500']

# every image has an attributes dictionary
#
# the following attributes are available:
# 'frame_id'    --  frame ID as reported by the camera
# 'tstamp'      --  UNIX timestamp, seconds since 00:00:00 UTC on 1 Jan 1970
# 'exposure_t'  --  image exposure time
#
# note: calibration images only possess the 'tstamp' attribute
port_attrs = im_port.attrs
star_attrs = im_star.attrs

print('Camera: Port')
print(f"Frame ID: {port_attrs['frame_id']}")
print(f"UNIX timestamp: {port_attrs['tstamp']}")
print(f"Exposure time: {port_attrs['exposure_t']}")
print()
print('Camera: Starboard')
print(f"Frame ID: {star_attrs['frame_id']}")
print(f"UNIX timestamp: {star_attrs['tstamp']}")
print(f"Exposure time: {star_attrs['exposure_t']}")

if IMSHOW:
    import matplotlib.pyplot as plt

    fig,(ax0,ax1) = plt.subplots(2, 1, sharex=True, sharey=True, figsize=(16,9))
    
    ax0.imshow(im_port, cmap='gray')
    ax0.set_title("Camera: Port "
                    + f"Frame ID: {port_attrs['frame_id']}, "
                    + f"UNIX timestamp: {port_attrs['tstamp']}, "
                    + f"Exposure time: {port_attrs['exposure_t']}")
    
    ax1.imshow(im_star, cmap='gray')
    ax1.set_title("Camera: Starboard, "
                    + f"Frame ID: {star_attrs['frame_id']}, "
                    + f"UNIX timestamp: {star_attrs['tstamp']}, "
                    + f"Exposure time: {star_attrs['exposure_t']}")
    
    plt.show()