To convert a color image to black and white, simply strip out the color information and preserve the brightness information.

Traditional photos can be retaken, and digital images can be made more conveniently with the help of picture viewing software.

However, if it is the other way around, turning a black-and-white image into color is much more troublesome, and it is necessary to manually add the missing color information to it.

In 1839, the French painter/chemist Louis J. M. Daguerre invented the "daguerreotype". Although this wooden box camera requires a continuous exposure of 30 minutes to take pictures properly, which is very inconvenient to use, it has initially solved the problem of camera usability.

Since then, inventors have been working on the improvement of cameras and photographic materials, and by the time the Eastman Company, founded by the American George Eastman, introduced transparencies in 1885, it was almost the same as modern film (at first flammable celluloid film, later changed to safer acetate film). Later, around 1935, the company introduced 135 rolls of film with its own film cartridge and color film, which completely established the modern camera/film combination, and the company later changed its name to the "Kodak" that was once known around the world.

However, the initial price of color film was very expensive, and it would be thirty or forty years or more before it was fully popularized.

During this period, photographers took a large number of black-and-white photographs, while end-users were fascinated by color images, creating a huge demand for black-and-white to color.

At the same time as the invention of film, the Swiss inventor Hans J. Schmidt invented the "photochrom" photo colorization technology, which became the best of this kind of product. The principle is somewhat similar to that of lithograph color printing, where the staff reprints the black and white images onto finely ground limestone coated with photosensitive reagents, and then adjusts the colors according to their imagination to form a color image that can be used to print postcards, posters, and the like.

With the help of this technology, the Detroit Printing Company in the United States printed many colorful landscape and portrait postcards, up to 7 million copies a year. Later, as a large number of adult males were dragged into the battlefields of World War I, the Great Depression triggered by the 1929 stock market crisis made these large, beautiful and exotic photographs undesirable, and the Detroit Printing Company went into bankruptcy in 1932.

Interestingly, because some of the details of the photographs were omitted during the retouching, and the color palette was chosen out of subjective imagination, these photographs had an artistic taste similar to oil painting and gouache painting, but they were reborn in the collector's market decades after the company's collapse.

With the advent of personal computers, software capabilities have become more and more powerful, and ordinary people can do it with the help of Photoshop image processing software.

Compared with Photochrom, which continuously adjusts the color tone overprint, PS coloring is more simple and intuitive, but it is also time-consuming and labor-intensive, requiring users to save the photo into different hue/saturation layers according to the color partition, and then select the appropriate color from the similar color photo to add it, and finally save it as a complete photo. This kind of operation logic of image partitioning, color selection, coloring, and synthesis is obviously very in line with the characteristics of simple and repetitive mental work, and it is the most suitable battlefield for AI, especially deep learning AI.

With the help of the Internet, researchers can collect millions of color photos, convert them into black and white in batches, and then take them in pairs and hand them over to deep learning networks for training. Image recognition and coloring technology are extremely important to BeautyCam, this field has always been the focus of research of the software department of the Bee Research Institute, and the importance is even above the chip department, and the CPU part of the bee core has not yet abandoned the ARM architecture, and the GPU architecture is basically unchanged.

With the help of deep accumulation in related fields, Bee has successively launched comic coloring and photo coloring software, and now has the idea of hitting old black and white movies.

Coupled with bright colors, it can obviously make old movies glow with a different charm. As a test of the waters, the researchers chose anti-Japanese themes. There are too many anti-Japanese film and television dramas, and the related image resources are extremely rich, which is very suitable for training AI, and there is also a reference for manual color correction and trimming in the later stage.

It just so happened that Bee Pictures took over the task of digital restoration of "Tunnel War", and the Image Institute of the Research Institute took the initiative to find Bee Shadow and Bayi Factory, and quickly persuaded the latter two, and then there was the current color film.

Gunshots echoed in the valley, and devils wreaked havoc on the screen.

A color remake of "Tunnel Warfare" is currently being screened.

Although there are colors, the picture is not bright and clear, with a hint of haze and blur.

The audience apparently embraced the style and quickly became immersed in the plot.

As a tactical teaching film born in a special background, the structure of "Tunnel Warfare" is very clear.

The opening chapter begins with a subtitle introduction: "During the War of Resistance Against Japanese Aggression, the military and civilians in the base areas behind enemy lines ,...... Tunnel warfare is a shining example. ”

Then he uses the narration to introduce the straight to the topic: In 1942, the Anti-Japanese War entered a stalemate, and the Japanese army launched a large-scale sweep in North China in order to plunder human and material resources, which soon affected Gaojiazhuang, where the story took place.

The old village chief was injured when he went out for a meeting, and he barely returned and swallowed his breath, leaving only a carefully wrapped copy of "On Protracted War". The village party secretary took out the books to organize everyone to study, and decided to follow the instructions of the superiors to connect the hiding holes spontaneously dug in the villagers' homes to form a tunnel.

As soon as the tunnel was dug up, the devils came to sweep it, and the Japanese detachment captain Yamada instructed to "quietly drip into the village, don't shoot the drop", but was accidentally discovered by the branch secretary Gao Laozhong, and hurriedly ran to ring the bell to warn. Yamada was so angry that he took out a gun and killed Gao Laozhong, but he was attacked by someone, was shot in the buttocks, and hastily withdrew his troops at the suggestion of the puppet army Commander Tang.

After the death of Uncle Lao Zhong, the militia captain Gao Chuanbao led the villagers to continue fighting, and once again picked up the book "On Protracted War", realizing that "only by destroying the enemy can we better protect ourselves", and proposed to enhance the attack ability of the tunnel, and the complete authentic tunnel gradually took shape. Later, relying on this ever-expanding network of tunnels, the villagers saw through the devil spies who pretended to be the "Eighth Route Army's Armed Forces Behind Enemy Lines", broke the two encirclements and suppressions of the devils, and even dug the tunnels under the devil's turret, and took the old nest of the Yamada detachment in one fell swoop.

In the heroic singing of "tunnel warfare, tunnel warfare, and millions of divine soldiers in ambush", the movie also came to an end.

Seeing that the four-eyed devil with Ren Danhu was captured alive by the male protagonist with one hand, the adults and children present cheered one after another, and some people couldn't help but applaud.

The credits have been broadcast as early as the beginning of the credits, and the end credits only have a crisp and powerful handwritten inscription: "Long live the victory of the people's war".

The projector's pillar of light disappeared for a moment, the lights came on, and the arena was noisy, pulling the audience back from the war years.

Looking at the eldest daughter in her arms, Tang Jiayi turned her head and asked, "Why does the color feel weird?

Atletico held down his little son, who was not very restless, and asked with a smile: "Do you think the colors of the military uniforms of the Japanese army and the puppet army are strange, and they look very disgusting and ugly?"

The former's eyes lit up, "That's right, that's it!"

"This is the result of intentionality," Atletico Madrid did not continue to explain, but turned to the eldest daughter with a smile, "Zhizhi, do you understand?"

The three-and-a-half-year-old girl's answer is very simple and intuitive: "The white clothes are good people, the yellow clothes are bad guys, and the good guys beat the big bad guys!"

Tong Yan immediately amused the couple, and Atletico continued: "See? ”

The colors of the military uniforms in different versions of the film and television dramas are different, and the production team did not choose the one recommended by AI, but deliberately chose the kind of color that is close to the old photos but is disgusting. On the contrary, the people on the protagonist's side, although they are all dressed in homespun clothes, are all clean, bright and friendly. The purpose of this is, of course, to distinguish factions with the help of colors, with neat and ugly military uniforms on one side and simple but friendly regular clothes on the other, so that even children can complete the identification of friend and foe.

As the owner of a clothing company, Tang Jiayi actually understands color psychology and color emotion. It's just that she is used to watching all kinds of anti-Japanese film and television dramas, and subconsciously compares the military uniforms in the movie with the costumes in later film and television dramas, and forgets this stubble for a while.

Realizing her negligence, Tang Jiayi blushed slightly, stood up and took her daughter to the toilet, she changed the topic by the way: "Didn't you say that you did digital restoration? Why is the resolution still not too high?"

Atletico Madrid also got up and pulled his son, whose face was flushed, "The repair is mainly aimed at serious noise defacement and noise, and then adjust the volume of the background music, and the rest of the place is not disturbed." Because of the equipment and film, the resolution of this movie itself is not high, and now this is the limit, and it will be even more distorted if it continues to be amplified. Besides, don't you think that this kind of slight noise and blurry sound gives people a sense of vicissitudes unique to old movies? If it is clearer and becomes a 'grinding grandmother', you should complain about 'how to become an anti-Japanese drama'. ”

"Actually, it's also very godly now," sent the little ones to the special children's bathroom, Tang Jiayi still couldn't help complaining.

"Obviously, the battlefield situation is that the enemy is strong and we are weak, and in the face of an enemy with light and heavy firepower and long-term training, our ordinary militia actually relied on the mounds of earth and brick walls, ground mines, and grenades to kill and wound them, but their own injuries were only in single digits. ”

Atletico immediately picked up, "To be exact, the 'personnel battle damage' should actually be 0, the villagers who were captured, those who were killed, the old village chief, the village party secretary, and the villagers are all non-combatants, and they should not be counted." If you search for 'tunnel warfare' on the 1905 movie network now, you will see that its genre tag is comedy/drama/war. 1905 is a website under the movie channel of the General Administration, which is equivalent to an official evaluation. ”

As soon as the voice changed, Atletico said: "Actually, this situation is not unique to 'tunnel warfare', this phenomenon existed in most of the anti-Japanese films of that year, and the same is true for Liberation War films." After all, the primary function of these films is propaganda and mobilization, not to exaggerate violence under the banner of reflecting on war, and naturally they cannot deliberately exaggerate the cruelty and danger of war in terms of plot and picture performance. The fact that we liked movies like this back then has something to do with this light-hearted atmosphere. ”

"Think about it from another angle, 'tunnel warfare' is a tactical instructional film for the militia, a sales advertisement for potential users, and it is natural to double the promotion of benefits and hide disadvantages. Fat people and sick people do not appear in advertisements for instant noodles and hamburgers, traffic jams never appear in car advertisements, and it is understandable that the movie is undamaged and the battle is easy. ”

"Of course, no matter how much 'tunnel warfare' evades the important and exaggerates the facts, it still has a real factual basis. The Ranzhuang militia used the tunnels to fight against the enemy more than 100 times, and the deeds of destroying more than 2,100 enemies are real, and the tunnel warfare in North China is also a real thing. And the reason why anti-Japanese dramas are hated is because they abuse fictional plots, which further amplifies this sense of lightness, so that it is false and exaggerated, making it difficult to believe that this is real. ”

"Theoretician, you stay here and wait for the child, I'll go to the bathroom. ”

Leaving these words, Tang Jiayi stepped into the public toilet on the side.

Everyone ran away, and Atletico crooked his mouth to stop talking, looking up at the starry sky overhead.

It's only early twenties, and it will take some time for the second quarter moon to rise, and when you look up, you can see hundreds of bright stars, and even the Milky Way can faintly see a little outline.

Because it involves optics, mechanics, and chemistry, photography has always been synonymous with high precision, and its early development was quite slow.

As early as 1935, the American film "Vanity World (Vanity Fair)" came out, which had already announced the arrival of the era of color films.

However, the early color film was cumbersome and expensive to produce, and it took more than 20 years to replace black and white film as the mainstream of world cinema.

On the Pacific side, the process is slower because the industrial base is weaker.

Although as early as 1948, the color opera film "Life and Death Hate" starring Master Mei Lanfang was put on the screen, but the full colorization of domestic films did not wait until the 1980s.

Before the launch of color film/film by Lekai, color film was a luxury that needed to be imported, and only senior reporters who had been specially approved could receive a small amount of color film to record major events such as the National Day parade, going to the countryside, learning Lei Feng, and resuming the college entrance examination.

Even more so, the use of kilometer-long color film is even more valuable, and the color films that can be filmed are all major subjects, such as the feature film "Blessing" shot in 1956 to commemorate the 20th anniversary of Lu Xun's death, and the documentary documenting the atomic bomb project in 1963.

In fact, not only color film is a luxury product, but also black and white film can not be used for a long time, until the predecessor of the company, Baoding Film Factory, was completed and put into operation, and domestic film talents gradually got rid of the embarrassment of being overstretched.

It's a pity that with the changes of the times, film films have been completely launched on the stage of history. Film manufacturing and printing production lines around the world have been closed one after another, and Lucky has also transformed into a comprehensive material chemical enterprise, the technology is still cutting-edge, but it is gradually away from people's sight, just like these film films.