Chapter 1412 - 1336: Level 3 Features
What exactly did Jiang Yuan use for image enhancement? On site, only two technicians from the provincial department were concerned, because they actually knew how to use it.
Yet, both of them were likely at a practical level, probably just Level 1, hardly reaching Level 2.
However, when Jiang Yuan continuously changed the plans and eventually output several different versions of the same fingerprint, all the fingerprint experts gathered around.
The same fingerprint with detailed line features became clear and rich, while the change in contrast also significantly improved the image quality.
This was an undeniably clear change, a completely utilizable transformation. Anyone with even a little fingerprint research would realize how much this helps with difficult fingerprints.
Li Zemin enviously took a whole pack of Zhonghua cigarettes from Jiang Yuan’s table, took a heavy puff, shook his head, and went back to his seat to continue working.
The other fingerprint experts glanced around and then dispersed.
"Oh, is it not going well?" Zhang Limin, watching with a smile nearby, became a little anxious.
"It’s going well." Li Zemin exhaled a faint smoke ring: "It’s just boring."
Zhang Limin sighed in relief upon hearing this and smiled, saying, "As long as it’s going well. Fingerprint comparison is inherently a bit tedious."
"I don’t mind tedious work." Li Zemin chuckled twice, saying, "We can’t play Jiang Yuan’s game. His ridge detail is clear enough for Level 3 feature comparison."
"Level 3 feature comparison, what do you mean?" Zhang Limin asked curiously.
Li Zemin took another slow drag, "Level 1 features are ridge characteristics, such as arch, loop, and whorl patterns, which ordinary people can distinguish with one glance. Level 2 features are the minutiae we normally use, like hooks, eyes, blocks, bridges, and dots. Level 3 features are the microscopic details of fingerprints, including ridge edge morphology, ridge width, specific point numbers, and pore characteristics, which can be used on a high-resolution basis."
Li Zemin pouted again and said, "The clarity of the fingerprint Jiang Yuan extracted is enough for that."
Zhang Limin understood suddenly and then said rightly, "I seemed to have heard members of the ministry mention the promotion of this technology before, there should still be some difficulty, right? Is it the problem with high-definition resolution?"
Li Zemin nodded, "The advantage of Level 3 features is that the fingerprint does not need to be so extensive. Even a broken fingerprint, as long as the clarity is enough, can be used for comparison even if it’s just a small area. The problem is..."
Li Zemin laughed, "Our fingerprint database does not have such high definition. So, it can only be used for secondary comparison."
"Secondary comparison works too." Zhang Limin instantly understood, and without mentioning further promotion, said, "So, we identify the suspect first and then use Level 3 features for a comparison to see if it’s the right person."
"Theoretically, yes." Li Zemin nodded slowly, hesitated a bit, and said, "Academically, there is still debate on this issue. Especially with Level 3 fingerprint extraction and matching, the difficulty is quite high, and regular technicians often make errors. You can see it from what Jiang Yuan did."
Zhang Limin suddenly realized, "You all can’t do it, so it’s boring?"
He grilled cow eyes because he only cared if people who liked eating cow eyes were happy, and didn’t concern himself with those who didn’t enjoy cow eyes.
Li Zemin was amused by Zhang Limin’s provocation, "I can do Level 3 fingerprint extraction and matching, but image enhancement is another craft. Apart from someone like Jiang Yuan, who else can you ask?"
Zhang Limin looked around, realizing indeed no one else raised their head.
"No need to look further; talent like that can hardly be found domestically." Li Zemin scoffed, "With such skills, internet giants, Hollywood companies, and gaming companies are all vying for them, easily offering a million dollars a year."
Upon hearing this, Zhang Limin understood immediately, turned around and took out his phone, babbling, "Leave me all the cow eyes from the slaughterhouse, and some beef too. Don’t they slaughter cattle at dawn? Send it over while the beef is still twitching. Why is it called jumping beef? Haven’t you watched food videos? It’s the kind of meat that’s still twitching when the cow is freshly slaughtered."
Zhang Limin spoke loudly on purpose, and when he put down his phone, the experts around also heard it.
He couldn’t offer a million a year, so he could only resort to cow eyes as compensation.
At this time, Jiang Yuan, having completed the fingerprint scanning on the screen, pressed print and turned around, "No more food for now, I’ll get back to work for two more hours before going to sleep. Liu Zhi, please send someone to collect the fingerprints from these people. Once I’ve rested, I’ll compare them. Follow Captain Li’s instructions, collect high-definition fingerprints, capable of Level 3 fingerprint matching."
Liu Zhuang rushed over. This arrest mission was all about the Anwan City Bureau, and the municipal bureau tasked the Anwan City Criminal Investigation Team with the job.
Zhang Limin was waiting impatiently nearby. He had been up so long for this moment and hurriedly asked, "Is it a match? Did we match with the homicide case?"
In any fingerprint battle, matching a homicide fingerprint counts as a success.
It’s obvious that fingerprints entering into the fingerprint battle are often from unresolved cases, not freshly committed crimes. Hence, they aren’t typically easy fingerprints.
Jiang Yuan handed the freshly printed document to Zhang Limin and said, "Based on the partial fingerprints, I listed 8 individuals. These 8 people have at least six or seven matching minutiae. Additionally, regarding the Level 3 minutiae that Captain Li mentioned, parts also match among these 8 people. Once Liu Zhi retrieves the high-definition fingerprints, re-matching will confirm if anyone was identified."
Jiang Yuan continued, specifically telling Liu Zhuang, "The fingerprints were collected from the outer jacket of the deceased. Judging by the location of the defensive wounds, the fingerprints used for comparison are likely the criminal’s, so be cautious! On the other hand, they might just be pre-existing fingerprints from related individuals. Therefore, even if someone among these 8 is identified, pay attention to the method when locating them."
Zhang Limin immediately reached out, flipping his hand back and forth, and said, "Be measured, treat them politely, bring more people, be vigilant."
"Understood." Liu Zhushì nodded immediately, "One group of 4 people, 8 groups in total."
He looked at the ID numbers on the printout, people from all over were included, but since the fingerprint battle had just begun, there was no shortage of people under his command.
Li Zemin specially urged, "Among the ones dispatched, ensure there are personnel trained to extract high-definition fingerprints — either trained detectives or bring a field examiner or trace examiner. How high-definition? 1000 PPI or above scanning resolution?"
The last question was directed at Jiang Yuan. This was the standard set by the Old American National Institute of Standards and Technology in 2005.
Jiang Yuan responded with a nod, "Preferably at 1000. If no one is available, and you must use non-contact fingerprint acquisition, a minimum of 500."
"500 will do?"
"500 allows recognition of pore positions in grayscale images." Jiang Yuan said.
With their question and answer, Liu Zhuangshi didn’t quite understand but immediately decided, "I’ll assign a forensic specialist to each group."