Experts’ methods for identifying Edison Chen’s “pornographic” photos:
Analysis methods and conclusions of six postgraduate students studying in the Department of Computer Science at the Australian National University:
1. The so-called "synthetic" pictures have no traces of modification and are natural pictures. By using ZINX to magnify key parts (5000%-8000% magnification, the current maximum magnification of software such as Photoshop is only more than 1000) and conducting decomposition domain analysis, no signs of changes were found. Using 32-digit missing data to scan some key parts (such as the neck, skull and surroundings, sensitive parts), no IND (intruding data, bitmap terminology, used to find data missing due to changes, the minimum can reach 100bit level).
2. Field tone analysis of the original image, the unanimous conclusion is that the tone is the original, and no trace of image modification was found.
3. No abnormalities were found in the shadow analysis and light source projection analysis of the original image, which were both correct light sources and normal shadows.
4. Using the image differential analysis tool independently designed by the National University, the final data obtained was (-30, +47), which is within the normal range, and no data tag of any image modification tool was found.
5. The final conclusion is: the picture is the original picture without modification.
A senior photographer's technical analysis on how to identify whether Cecilia Cheung's nude photos are synthetic: they are not grafted.
Although the original shooting data is not available for this photo, looking at the noise level, it is estimated that the ISO is 200-400, the flash is on, and the focal length is about 28-32mm (not converted). The noise level, color temperature, and perspective of the character's head in this photo are all consistent with the environment and shooting parameters. There are no flaws in the translucent parts of the neck and hair edges. The light spots on the eyes and teeth are flash spots, and the angles are consistent with the photo. Other light spots are consistent, the shadow of the head in the photo is consistent with the environment, and it is front-lit. Through the above observation, it can be considered that the photo was taken by the same flash. Therefore, it is determined that this photo is not an imitation, and it has not even been through PS, and the output software is ACD Systems Digital Imaging.
Hong Kong police’s method of identifying pornographic photos: no manual repair
In addition, an expert team headed by Chief Inspector Cheng Kwok-cheng, head of the Computer Forensics Section of the Commercial Crime Investigation Bureau, is examining seven pornographic photos of suspected entertainers Edison Chen, Gillian Chung (Gillian), Cecilia Cheung and BoBo. The source said that after preliminary verification, it was still not possible to determine whether the photo was a fake. A detective said: "There is no manual repair on the surface of this batch of photos. The resolution of some photos is very low. It cannot be ruled out that they were taken with mobile phones."
How netizens identify the authenticity of photos:
1. When you cannot obtain the original file taken, you can only see the image reduced or converted to JPEG format on the Internet.
You can look at the overall feeling of the photo. Some synthesized pictures have very different colors, or the connection between the two objects is not very coherent. This can be easily distinguished at first glance. For some pictures that are difficult to identify, we can first look at the direction of the light, and the reflections of hair, face, and clothes can also be seen. There are also two objects that need to be looked at the resolution of. Generally, some are enlarged or reduced and then synthesized. Painters who don't pay attention to details will ignore this. Of course, you can also check to see if the edge of the hair blends well with the background. Some people's hair has a lot of thorns, so there will inevitably be choices when choosing. We should pay attention to this.
2. If you can get the original files, digital ones are RAW and traditional ones are negatives. (Photography competitions generally require original documents)
Because the original photo must have not been modified in any way, and as long as one modification is found, it can be proven to be fake.
(1) Check the Exif "metadata" of digital photos: Use Notepad to check roughly, check directly in the digital photo folder window under Windows XP, and use professional software to check the complete Exif information.
(2) Use digital image original data verification management tools.
For example, in 2004, Canon designed and developed the digital image original data verification management tool-Suite DVK-E2 specifically for Canon EOS-1Ds and EOS-1D Mark II SLR digital cameras to verify whether the image has been altered to verify the use of Whether the photos taken by these two digital cameras have been modified.
Finally, it is reported that there are some software that can directly identify. It can scan the hidden features in the binary code of the data file to find traces of damage, thereby determining whether the photo has been modified.
The principle is that any operation performed with software such as Photoshop or iPhoto will leave specific statistical traces in the file and appear repeatedly in the file. You can try this.