Colorize

Colorize is the process of applying color to grayscale or monochrome media, such as photographs, video, or film, so that the final image contains color information. The goal is to recreate or simulate natural color based on evidence, context, or artistic direction. Colorization is distinct from tinting or toning, which alter the overall color tone of a luminance image without introducing separate color channels.

Historically, colorization has roots in early cinema techniques such as tinting and toning used in silent films. In the late 20th century, digital colorization of black-and-white films became commercially viable, producing colorized versions of classic titles. The practice sparked debate about authenticity, authorial intent, and audience manipulation. Modern digital colorization relies on frame-by-frame work by artists or on automated algorithms, often with color grading to maintain consistency with the film's era and lighting.

Techniques include manual colorization, where artists paint color into each frame using software; and algorithmic colorization, which uses machine learning or exemplar-based methods to propagate color from reference images or learned priors. Recent approaches combine deep neural networks with user input and frame tracking to maintain temporal coherence across sequences.

Applications include restoration of archival footage for educational or entertainment purposes, artistic reinterpretation, and demonstrations in computer vision research. Limitations include potential color inaccuracies, the subjectivity of color choices, and the risk of altering the original work's historical record. Ethical and legal considerations are discussed when colorizing cinematic works.