Medicine benefits from the techniques of tomography, including cutting-edge ideas like electrical impedance tomography that may greatly improve the detection of cancerous tumors, and MRI, where level set and marching methods can be used in the extraction of images of beating hearts. Computer imaging depends on a whole range of mathematical tools. Without proper illumination, the images created by computer graphics would appear flat and artificial rather than realistic and visually pleasing. Storing computer images is another challenge. Familiar references like Microsoft's Encarta encyclopedia and its 7000 color images fit on a single CD-ROM because of fractal image compression techniques.
Image compression is also one of the essential tools of space exploration.
Compression routinely increases the effective transmission rate of image data by a factor of 15 or 20. New techniques now being developed will raise compression ratios into the hundreds while still preserving essential features of the image. One of these new ideas, wavelet image compression, has already made possible the electronic storage and retrieval of the FBI's vast archive of fingerprint records. Image restoration tools can extract detail that would otherwise be hidden in images from a wide range of sources, including satellites, medical imaging devices, telescopes, and even amateur video pictures submitted as courtroom evidence. Images from astronomical telescopes are cleaner to begin with if they have benefited from the control strategies of active and adaptive optics.