Search Results (4)

This paper introduces a novel loss function, the boundary Gaussian distance loss, designed to enhance character segmentation in high-resolution scans of old metal-type printed documents. Despite various printing defects caused by low-quality printing technology in the 14th and 15th centuries, the proposed loss function allows the segmentation network to accurately extract character strokes that can be attributed to the typeface of the movable metal type used for printing. Our method calculates deviation between the boundary of predicted character strokes and the counterpart of the ground-truth strokes. Diverging from traditional Euclidean distance metrics, our approach determines the deviation indirectly utilizing boundary pixel-value difference over a Gaussian-smoothed version of the stroke boundary. This approach helps extract characters with smooth boundaries efficiently. Through experiments, it is confirmed that the proposed method not only smoothens stroke boundaries in character extraction, but also effectively eliminates noise and outliers, significantly improving the clarity and accuracy of the segmentation process. Full article

Since the 1920s, nearly six identical versions of an ancient printed book, The Song of Enlightenment with Commentaries by Buddhist Monk Nammyeong Cheon (南明泉和尙頌證道歌), have been found in Korea. Until very recently, they were believed to be woodblock-printed versions from the 13th to 16th centuries using woodblocks carved from the sheets of a metal-type-printed version from 1239. Two of the six versions were once identified to be woodblock prints in the Goryeo dynasty in the 13th century and designated as Korean treasures in 1984 and 2012. In 2021, one woodblock-printed version printed during the Joseon dynasty in 1526, was designated as a treasure of the Metropolitan city of Seoul, Korea. Historians in Korea have been in heated debate over the printing techniques (metal type print for one version or all woodblock prints) and printing dates (or sequence) of the two versions designated as Korean treasures for the last 50 years. It was almost a never-ending debate with struggles and anger among Korean historians due to the very subjective nature of the examination method and decision-making process by consensus. The heated debates in Korea were never brought to the world’s attention, outside of Korea, and are still considered to be a taboo subject in Korea. To conclude this heated debate with direct evidence of metal type printing of the particular version of interests, all six versions were examined by image comparisons and quantitative analyses of inked areas of individual characters, lines of characters, pages and borderlines. All claims against the possibility of metal type printing of the particular version were reviewed thoroughly. Very clear circumstantial and physical evidence for metal type printing of the version designated as a Korean treasure in 2012 was found. The version carries more than metal casting defects and has the smallest inked area (characters with thin strokes) among all six versions. The version of interest was very likely printed using movable metal type in September 1239, as indicated in the imprint, and is definitely the world’s oldest extant book, printed using metal type in Korea in 1239, predating Jikji (1377) by 138 years and the 42-line Gutenberg Bible (1455) by 216 years. Full article

Six nearly identical versions of an ancient printed book, The Song of Enlightenment with Commentaries by Buddhist Monk Nammyeong Cheon (南明泉和尙頌證道歌), have been found in Korea since the 1920s. All of them were believed to be printed versions from the 13th to 16th centuries that used duplicated woodblocks of a metal-type-printed version from 1239 and its replica. Two of the six versions were designated as Korean treasures in 1984 and 2012. One other version was designated as a treasure of the Metropolitan city of Seoul, Korea in 2021. Since the 1970s, one of two Korean treasures has been identified as a potential movable metal-type-printed book prior to the Jikji printed in Korea in 1377, as recognized by the UNESCO Memory of the World program. The center of heated debates among Korean historians for the last 50 years was over the printing techniques and printing dates (or sequence). Due to the subjective nature of the examination, it was very difficult to reach a consensus. To end this heated debate, all six versions were examined by image comparisons of individual characters, lines of characters, pages and borderlines to identify whether they are the identical versions using the same woodblocks or different versions. Previous reports on the subjects were also reviewed very carefully. Very clear circumstantial and physical evidence showed that the one version designated as a Korean treasure in 2012 is significantly different from the others and was very likely printed using movable metal type in September 1239, as indicated in the imprint. It is the world’s oldest extant book printed using metal type in 1239, 138 years prior to the printing date (1377) of Jikji. The mystery of the misidentification of the metal-printed book, as a woodblock print, has been revealed. Full article

Four nearly identical versions of an ancient printed book, the Song of Enlightenment with Commentaries by Buddhist Monk Nammyeong Cheon (南明泉和尙頌證道歌), were examined by image analysis and comparisons to identify whether they are the identical versions or different versions in terms of printing techniques. Two out of four versions have been designated as Korean treasures and the other two versions are currently being examined for designation as Korean cultural properties. One of two Korean treasures has been spotlighted as a potential movable metal type printing book prior to the Jikji printed in 1377, as recognized by the UNESCO Memory of the World program. Heated debates over the printing techniques and printing dates have overwhelmed Korean historians for more than 50 years. Due to the subjective nature of the evaluation, it was hard to reach a unanimous decision. Finding objective new evidence is needed to end this heated debate. We found very clear evidence showing that one version is significantly different from the others and was likely printed using movable metal type in September 1239. It is the oldest extant book printed using metal type, 138 years prior to the printing date of Jikji. Full article