Camera Basics

1. at present camera Divided into two （ According to the output image data ）：SOC And RAW

RAW： Output the original RAW Images , The subsequent image processing needs the platform （MTK/ Exhibition / qualcomm ） Of ISP Come to The reason is . This is the same as we often use SLR camera output RAW After the image , Then use special software on the computer to deal with the later effects .

SOC： stay RAW On the integration of ISP, You can directly debug the effect on it , Output yuv/jpeg Images .

SOC= RAW+ISP

therefore , If we plan to use RAW camera , It must be confirmed AP Do you support RAW Support . On the Spreadtrum platform ,sp5735,sp7731 Support RAW Standard camera .

stay android On ,camera Drive in kernel layer , Image effect debugging is in HAL Layer of ISP.

2.lens

（1）. The quality of the lens will obviously affect the image effect of the camera （ If you think about those expensive SLR lenses, you'll be relieved ）;

（2）. The lens of the lens is divided into 3p,4p even to the extent that 5p（ Number of lenses ）, The materials are plastic and glass . It is generally believed that ： The more lenses, the better , Glass lenses are better than plastic lenses ; At present, the best camera lens manufacturer in the industry is Taiwan's Dali optoelectronics （ Apple mobile camera supplier ）.

p yes plastic It means ,2P Refer to 2 A plastic lens ,3P4P And so on ; In addition, mobile phone lens terms are often mentioned G, finger glass Glass lens ,2P1G---2 A plastic lens 1 A glass lens , And so on . among G The more films, the better the effect of the lens , At the same time, the more expensive the price .

（3）. Different shots , Yes sensor The image effect is different , So for different shots , Different configuration codes are required （ Just like the same LCD IC, Use different glasses , You need to configure different initialization codes ）;

3. About sensor device

（1）. The size is divided into 1/5`（5.08mm),1/4`（6.35mm),1/3.2` etc. ;

（2）. encapsulation ： It is divided into CSP and COB

COB：DIE It's just the photosensitive chip itself , Low packaging cost , So the price is CSP low , Height Low , Save space . But the requirements for the equipment of the module plant are high , Invest heavily . As a result, the ex factory price of the module was initially high , When the amount is large, it will be CSP It's low . Large factories usually adopt this kind of .

CSP：COB+ Other modules （ For example, glass ）. Price comparison COB high . But the environmental requirements are low , Low requirements for equipment of module plant , Short production cycle . The disadvantage is the high module height , Poor light transmittance . Small factories usually purchase this kind of package .

4. For one 5.0Msensor, There is 5 Millions of light spots , There is one at each point microlensens( Micro lens ), There's only one color （ One color per dot , Instead of 3 Color , The other two colors are calculated according to the algorithm formula according to the color values of several adjacent points ）.

5.blacklevel( Black level ）

For camera sensitive chips , In theory, in a completely black environment （ The input light is 0）, The output sampling data should be 0. But in reality, this is impossible , Especially when the ambient temperature is high, it is impossible to achieve . To avoid this problem , At a certain effective photosensitivity pixel Next to it are placed a few that are not sensitive to external light pixel. Subtract the number of invalid sensations before outputting the sample value blacklevel, Only then is the truly effective image signal .

6. About RAW Camera tuning, Special tools for Spreadtrum platform ----SpreadtrumISP tool.

Key points of commissioning ----- The lens shading correction （ Because of the physical properties of the lens , It causes the brightness around the image to gradually decrease relative to the center brightness and changes in the color uniformity of the image . Use LNC correction , Make the image brightness and color even ）