The default observations are named tuples with two fields
img
: ah x w x (2 * c)
array whereh, w, c
are the height, width, and number of channels of the environment.c
can be 3 or 1 depending on whether the observations are grayscale. There are2 * c
channels in the observations because the two most recent frames are both included (the lastc
channels correspond to the most recent frame).vector
: any additional observations are included as a 1D array; the size of this varies by environment
Each environment has the following arguments affecting the observations
img_scale
: a factor by which to downscale all of the images (e.g.img_scale = 2
means the observations will be half of their original size). We set this to 4 in our experiments.grayscale
: whether to use RGB or grayscale images for the observations. We use grayscale images in our experiments.oracle_obs
: if true, the observations are the symbolic states of the environment instead of images. Each observation will be a 1D array whose length and values are environment-specific. This is mainly for debugging and is not used in our experiments.