The film contrast is the ability of a film to translate contrast of various tissues to differences in the resulting image. Film contrast depends on both film characteristics and processing.

A film processor is a peripheral x-ray equipment used in conjunction with a camera to create hard-copy images. Film processors should be maintained at their optimum operating conditions by regular quality control procedures. Optimal film processing has important implications for the diagnostic quality of the image stored on film.

Different filter types are used in medical imaging to improve image quality.
Filter materials such as aluminum, iron or copper, located in the primary x-ray beam between tube and collimator, filter out lower energetic x-rays (for example bow-tie filter). Filters partially absorb or attenuate the x-ray beam to prevent radiation overexposure. The sum of filtration consists of inherent and added filters. This filtration affects the beam energy and ability to penetrate materials.
Mathematical filter procedures are used for the convolution of the attenuation profiles and reconstruction of computed tomography (CT) images.

Filter grids are used to reduce scattered noise and increase contrast in x-ray images. Primary radiation passing through an object gets scattered caused by the various density of different materials. Scatter radiation produces noise (radiographic fog) on the film or detector, which degrades the diagnostic quality. Anti-scatter grids act as filters between patient and film (or receiver) to remove scatter radiation. The use of a grid is recommended with body parts thicker than 10 cm and kVp values about 60 kV.
X-ray filter grids are available with focused or parallel strips. These two types are produced with linear or crossed grid configurations. The septa of filter grids consist of high radiation absorbing materials (e.g. lead) separated by permeable parts. During radiation exposure, movement of the grid blurs a projection of the septa.
If the image receptor and x-ray tube (with the focal spot) are in a fixed position relative to one another the grid is automatically aligned. In mobile radiography, the position of the focal spot and the image receptor is variable. Additionally cassettes incorporating anti-scatter grids are also available.

X-rays contain a range of energies (polychromatic photons), the higher energies pass through the patient, the lower energies are absorbed or scattered by the body. Ideally, the x-ray beam should be monochromatic or composed of photons having the same energy. Strong filtration of the beam results in more uniformity. The more uniform the beam, the more accurate the attenuation values or CT numbers are for the scanned anatomical region.
There are two types of filtration utilized in CT:
Inherent tube filtration and filters made of aluminum or Teflon are utilized to shape the beam intensity by filtering out the undesirable x-rays with low energy. Filtration of the x-ray beam is usually done by the manufacturer prior to installation. The half value layer provides information about the energy characteristics of the x-ray beam. Too much filtration produces a loss of contrast in the x-ray image.
A mathematical filter such as a bone or soft tissue algorithm is included into the CT reconstruction process to enhance resolution of a particular anatomical region of interest.