Images of Venus taken by Russian Venus landers Venera 9 and Venera 10 in 1975.
Don Mitchell restored them using the inpainting algorithm, and the inpainted 
versions are now at NASA's data archive.

"In each case, the top image is the raw 6-bit telemetry, about 115 by 512 pixels.
Automatic gain control and logarithmic quantization were used to handle the
unknown dynamic range of illumination.  The raw image was converted to
optical density according to Russian calibration data, then to linear
radiance for image processing.  It was interpolated with windowed sinc
filter to avoid post-aliasing (a "pixilated" appearance), and the modulation
transfer function ("aperture") of the camera was corrected with a 1 +
0.2*frequency**2 emphasis.  This was then written out as 8-bit
gamma-corrected values, using the sRGB standard gamma of 2.2.  The bottom
image is a digitally in-painted version, using Bertalmio's isophote-flow
algorithm."



Venera 9

Copyright 2003  Don P. Mitchell.  Used with permission.  All rights reserved.

Venera 10

Copyright 2003  Don P. Mitchell.  Used with permission.  All rights reserved.