Projet 3B : Caméra panchromatique visible à profondeur de champ augmentée
Aujourd’hui, la plupart des caméras comprennent un système optique,
un détecteur et un traitement numérique de l’image. L’optique et le traitement
sont généralement conçus séparément : le système optique est optimisé de
façon à produire la meilleure image possible sur le détecteur, puis le
traitement vient corriger et améliorer la qualité de l’image. Pour augmenter
les performances d’imagerie des caméras, il devient nécessaire d’optimiser dans
le même temps le système optique et le traitement : c’est la conception
conjointe optique/traitement (ou « co-conception »). Cette approche est particulièrement adaptée à
des systèmes dont on souhaite augmenter la profondeur de champ, sans modifier
l’ouverture ou la focale.
Au cours de ce projet, vous concevrez et optimiserez une caméra panchromatique pour l’observation de petits objets (circuits électroniques, fleurs, lego…) dans le spectre visible. La profondeur de champ sera augmentée sans modifier l’ouverture afin d’avoir une image nette d’objets positionnés à différentes profondeurs sans avoir besoin de refocaliser. Pour cela, vous optimiserez conjointement un masque de phase, placé dans la pupille de la caméra, avec un traitement de déconvolution2. Vous mettrez en évidence l’augmentation de profondeur de champ par des simulations d’images et par la comparaison des performances du système optique sans/avec augmentation de profondeur de champ. Le système devra être fabricable : une étape de tolérancement est donc attendue, ainsi que la conception d’une enceinte optomécanique.
Journal de bord du groupe
Friday, 26 Apr.
CHEN Jiaqi: Improve the 3D model of the camera and make it realizable. Improve the figure plotted with matlab and add some necessary labels.
LIN Chen: Find reasonable structure of the 3D model of the camera and design it in SolidWorks.
SUN Yimeng: Poster work, chech all the parts including optical system, phase mask simulation and solidwork modeling.
XIE Yunze: Modifiy the Optical system's figure on the poster to make it clearer, and overview the poster to check if it has any mistakes.
WEI Xinyue: Reasonable absence.
Thursday, 25 Apr.
CHEN Jiaqi: Improve the figure plotted in matlab and correct the errors and misunderstanding part.
LIN Chen: Improve the mechanical design and find design help in textbooks.
SUN Yimeng: Check the parameters of phase mask to find the most reasonable combinasion, theories improvement.
XIE Yunze: Plot the MTF as a function of image position simulated in Zemax to verify if this result is correctly correspond to the result simulated in Matlab.
WEI Xinyue: Improve the poster to make it clearer and more precise.
Wednesday, 24 Apr.
CHEN Jiaqi: Modify the content of the poster and the 3D model.
LIN Chen: Changes to the poster based on the supervisors' annotations to our report.
SUN Yimeng: Optimise the simulation process and continue to design the poster.
WEI Xinyue and XIE Yunze: Modify the content and expression of the poster with the advice of the instructor.
Tuesday, 23 Apr.
All members: communicate with Mme Fontbonne on the project poster.
CHEN Jiaqi: complete the first version of the poster and make the 3D model of the camera.
LIN Chen: Add an explanation in the optomechanical design part of the poster.
SUN Yimeng: Choose plot on the poster and explain, such as MSE method.
WEI Xinyue and XIE Yunze: On the basis of adding a phase mask, Zemax is used to optimize the optical system. Complete the ‘Optical System Design’ section of the poster.
Monday, 22 Apr.
All members: feedback of our project report.
CHEN Jiaqi: start to make the poster.
LIN Chen: Import the lens from Zemax to SolidWorks. Design mechanical support.
SUN Yimeng: start to make the poster, explain the theory.
WEI Xinyue and XIE Yunze: Continue to optimize the optical system on Zemax (obtaining better FTM curves). Design poster layout.
Friday, 22 Dec.
WEI Xinyue and XIE Yunze: Optimized the MFT curve and achieved good results when the STOP radius was 9 mm.
LIN Chen and SUN Yimeng: We tried to optimizd the aberrations using corresponding operands. tried to ensure that the total length of the system was reasonable.
Thursday, 21 Dec. Afternoon
WEI Xinyue and XIE Yunze: The MFT curve was optimized and achieved good results when the STOP radius was 8mm, but the results were not ideal when the STOP radius was 10mm.
LIN Chen: I adjusted the lens to an object telecentric configuration and optimized it.
CHEN Jiaqi and SUN Yimeng : We tried to figure out the problem of the binary phase but didn't succeed. focus on the cubic phase mask. optimized the value alpha of the cubic phase mask to minimize the average MSE.
Thursday, 21 Dec. Morning
CHEN Jiaqi and SUN Yimeng : We modified the definition of the binary phase mask to make the MES curve symmetrical, however the MTF curve shows that the binary phase mask make things worse.
WEI Xinyue and XIE Yunze: Optimized the MFT curve with a STOP radius of 6mm and achieved good results.
LIN Chen: I started my design with a double Gauss lens closed to the specifications and analyzed the aberrations in order to write corresponding merit function.
Wednesday, 20 Dec. Afternoon
WEI Xinyue and XIE Yunze: Continue to optimize the system’s chromatic aberration and field curvature
LIN Chen: I continue to optimize the scaled lens, but it is difficult to reach the diffraction limit while ensuring that the structure is realisable.
CHEN Jiaqi and SUN Yimen: We plotted the modulation transfer function and compared the situation with the phase mask to the situation without the phase mask. We got satisfying curve for the cubic phase mask. But for the binary phase mask, the MSE curve is not symmetrical for some reason.
Wednesday, 20 Dec. Morning
CHEN Jiaqi and SUN Yimen: We corrected the error in the normalization of the PSF. We corrected the errors in the calculation of MSE. It seems that we have got the satisfying MSE curve for cubic and binary phase mask.
WEI Xinyue and XIE Yunze: Try to change some lenses from spherical to parabolic to optimize aberrations.
LIN Chen: For the part of optical system design, we study 2 structures. My structure doesn't satisfy the diameter of STOP, and I tried to scale lens. However, the total length and the diameter of spot-diagramme increased.
Tuesday, 19 Dec. Afternoon
LIN Chen, WEI Xinyue and XIE Yunze: Designed a afocal system (double telecentric lens) that meets the requirements and tried to optimise the aberration; also searched for relevant literature to gain a deeper understanding of the system structure
SUN Yimeng and CHEN Jiaqi: We corrected some errors in the program but the result is still confusing. Then we focus on the case of the binary phase mask. We rewrite some expressions and functions to make it more clear. We plotted the evolution of MSE of the binary phase mask case, but it's more confusing.
Tuesday, 19 Dec. Morning
WEI Xinyue and XIE Yunze: Tried a variety of lens material combinations to find the optimal lens combination
LIN Chen: Search an initial design of double telecentric lens.
SUN Yimeng and CHEN Jiaqi: We tried to correct the expressions in the process of Wiener Filter in order to restore the blurred image in the cubic phase mask case. We plotted the evolution of MSE as a function of the defocus. But the curve we got was far from what we expected.
Monday, 18 Dec. Afternoon
LIN Chen and WEI Xinyue try to design a lens that is telecentric in object space using THORLABS achromatic doublet.
SUN Yimeng and CHEN Jiaqi: Wrote the approximate expression of binary phase and tried to make it work in the simulation process which is similar to the case of cubic phase mask. But the restored image is still blurred.
Monday, 18 Dec. Morning
LIN Chen, WEI Xinyue and XIE Yunze try to create a initial design of afocal camera objective
SUN Yimeng and CHEN Jiaqi: We reorganize our thinking of this project. We check the previous code and corrected some errors.
Thursday, 26 Oct. Afternoon
SUN Yimeng and CHEN Jiaqi: Try to find out the relationships between PSF and the image
LIN Chen: Make the PowerPoint for presentation
Thursday, 26 Oct. Morning
SUN Yimeng and CHEN Jiaqi: Try to find out the relationships between PSF and the image
XIE Yunze: Construct the optical system in Zemax
LIN Chen: Make the PowerPoint for presentation and simulation in Zemax
WEI Xinyue: Bibliography and share data to organize future objectives and give instructions
Wednesday, 25 Oct. Afternoon
CHEN Jiaqi and XIE Yunze, SUN Yimeng : Combining the PSF , writing the Function of Wiener Filter and optimising parameters of this system.
LIN
Chen: Writing functions with Matlab of adding noise to the image.
WEI Xinyue: Bibliography and summarise the knowledge point.
Wednesday, 25 Oct. Morning
CHEN Jiaqi, SUN Yimeng: Completing the definition of the PSF. Visualising the angle of PSF.
LIN Chen: Writing project plan and distributing the tasks.
XIE Yunze and WEI Xinyue: Modeling a phase mask with Matlab. Bibliography.
Tuesday, 24 Oct. Afternoon
Learn to use SolidWorks
Tuesday, 24 Oct. Morning
Introduce more detailed principles of the entire system with the help of the supervisors.
LIN Chen: Writing project plan
SUN Yimeng and CHEN Jiaqi: Writing functions of stops and Wiener with Matlab
XIE Yunze and WEI Xinyue: Analysis of the camera's natural depth of field
Monday, 23 Oct. Afternoon
SUN Yimeng, XIE Yunze, CHEN Jiaqi and WEI Xinyue: Read the first paper and comprehend the principle of optimizing the phase mask , discuss the steps of this project.
LIN Chen: Writing the plan
Monday, 23 Oct. Morning
Presentation of the general project by the supervisors
Choice of the project
Brainstorming on the purpose of the project and the objectives to be achieved