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EP-4740171-A1 - METHOD FOR ACQUIRING A STACK OF IMAGES OF A SCENE

EP4740171A1EP 4740171 A1EP4740171 A1EP 4740171A1EP-4740171-A1

Abstract

The invention relates to a method (100) for acquiring a stack of images (PIL) of a scene by means of at least one camera module of an apparatus, said method comprising the following steps: - acquiring (110) a plurality of images of the scene, at least two of the images being acquired with different focuses, and - storing (116) a stack of images comprising at least a portion of the acquired images; characterized in that the method additionally comprises, prior to the acquisition step (110), a step (102) of adjusting the number of images to be acquired according to at least one parameter relating to the apparatus and/or at least one parameter relating to the scene. The invention also relates to a computer program, a device, an apparatus and a vehicle implementing such a method.

Inventors

  • LEGROS, ERIC
  • PETITGRAND, Sylvain
  • LUONG, BRUNO

Assignees

  • Fogale Optique

Dates

Publication Date
20260513
Application Date
20230708

Claims (14)

  1. 1. Method (100) for acquiring an image stack (PIL) of a scene with at least one camera module (202) of a device, said method comprising the following steps: - acquisition (110) of several images of said scene, at least two of said images being acquired at different focuses, and - storing (116) a stack of images comprising at least part of said acquired images; characterized in that it further comprises, prior to the acquisition step (110), a step (102) of adjusting the number of images to be acquired as a function of at least one parameter relating to said device and/or at least one parameter relating to said scene.
  2. 2. Method (100) according to the preceding claim, characterized in that the at least one parameter relating to said device is chosen from the following parameters: - battery level of said device, - availability level of at least one processor of said device, - speed of movement of said device, - free memory space, - complexity of the optical transfer function of the camera module, - etc.
  3. 3. Method (100) according to any one of the preceding claims, characterized in that the at least one parameter relating to the scene is chosen from the following parameters: - brightness of said scene, - complexity of said scene, and the number of depth shots of said scene, - number of depth shots of said scene, - mobility of scene elements, - etc.
  4. 4. Method (100) according to any one of the preceding claims, characterized in that it comprises a step (112) of generating, by calculation, at least one image, called estimated image, at a focus different from those of the acquired images, the image stack comprising said estimated image.
  5. 5. Method (100) according to any one of the preceding claims, characterized in that it comprises a step (114) of processing at least one, and in particular each, image of the stack of images before the storage step.
  6. 6. Method (100) according to the preceding claim, characterized in that, for at least one image, the processing step (114) comprises a correction of geometric aberrations introduced into said image by the camera module (202) during the acquisition of said image.
  7. 7. Method (100) according to any one of claims 5 or 6, characterized in that, for at least one image, the processing step (114) comprises a correction of the sharpness of said image, for example by using a point spread function, PSF (for “Point Spread Function”).
  8. 8. Method (100) according to any one of claims 5 to 7, characterized in that, for at least one image, the processing step (114) comprises a correction of chromatic aberrations introduced into said image by the camera module (202) during the acquisition of said image.
  9. 9. Computer program comprising executable instructions which, when executed by a computing device, implement all the steps of the method (100) according to any one of the preceding claims.
  10. 10. Stack of images (PIL), stored on a computer medium, obtained by the method (100) according to any one of claims 1 to 8.
  11. 11. Acquisition device (200) comprising means configured to implement all the steps of the method according to any one of claims 1 to 8.
  12. 12. Apparatus (300;400;500) comprising: - at least one camera module (202), and - at least one computing unit (210); configured to implement the method (100) according to any one of claims 1 to 8.
  13. 13. Apparatus (300;400;500) according to the preceding claim, characterized in that it is: - a smartphone (300), - a tablet (300) - a computer, - a television, - a headset (400), in particular a virtual reality headset or augmented reality headset, or - a medical imaging device (500).
  14. 14. Vehicle (600) comprising: - at least one camera module (202), and - at least one calculation unit (210); configured to implement the method (100) according to any one of claims 1 to 8.

Description

DESCRIPTION Title: Method for acquiring a stack of images of a scene. [0001] The present invention relates to a method for acquiring a stack of images of a scene. It also relates to a computer program and a device implementing such a method. It further relates to a user device, a medical device and a vehicle implementing such a method. [0002] The field of the invention is the field of acquiring image(s) of a scene with at least one camera module comprising an optical lens associated with a sensor. State of the art [0003] Techniques are known for acquiring several images, forming a stack of images, of a scene at different focusing distances. For example, the technique called focus bracketing, or focus stacking, is known, which makes it possible to capture a stack of images of a scene, each image being captured at a different depth of field. Then, this stack of images is used to represent the scene on a display medium, for example with a greater depth of field or with greater sharpness. [0004] However, current techniques have significant drawbacks. On the one hand, current techniques are very resource-intensive in acquiring the image stack. On the other hand, the image stacks obtained with current techniques can be heavy in terms of memory space, especially if the definition of each image in the image stack is large. Finally, the acquisition of the image stack applies identically to all scenes, regardless of the device used. [0005] An aim of the present invention is to remedy at least one of the drawbacks of the state of the art. [0006] Another aim of the invention is to propose a more efficient solution for acquiring a stack of images of a scene. [0007] Another aim of the invention is to propose a solution for acquiring a stack of images of a scene that is more suited to the conditions in which the scene is imaged. Disclosure of the invention [0008] The invention proposes to achieve at least one of the aforementioned aims by a method of acquiring a stack of images of a scene with at least one camera module of a device, said method comprising the following steps: - acquisition of several images of said scene, at least two of said images being acquired at different focuses, and - storing a stack of images comprising at least part of said acquired images; characterized in that it further comprises, prior to the acquisition step, a step of adjusting the number of images to be acquired as a function of at least one parameter relating to said device and/or at least one parameter relating to said scene. [0009] The invention proposes to obtain a stack of images of a scene, with a camera module, the focus of which is changed between each image. Thus, the stack of images comprises images of the scene comprising different areas of sharpness. Such an acquisition can for example be carried out by focus bracketing techniques, or any other technique known from the state of the art. [0010] Unlike current techniques, the invention proposes to adjust, before the acquisition step, the number of images acquired during the acquisition step, and this as a function of one or more parameters of the scene and/or one or more parameters of the device, in particular at the time of acquisition of the image stack. The invention therefore makes it possible to adjust the number of images in the image stack as a function of the scene and/or the device performing the acquisition step. Thus, the invention makes it possible to optimize the acquisition of a stack of images of a scene, since said acquisition takes into account parameters of the scene, and/or parameters of the apparatus performing the acquisition. In other words, the invention proposes to personalize the acquisition of a stack of images of a scene with an imaging apparatus, to said scene and/or said apparatus. [0011] For example, when the scene is not very complex, the number of images to be acquired can be reduced without degrading the quality with which the scene is imaged: this makes it possible to reduce the resources and the acquisition time of the image stack, but also the memory space for storing the image stack, without impacting, or with very little impact on the quality with which the scene is imaged. [0012] According to another example, when the scene is very complex, the number of images to be acquired can be increased: this makes it possible to maintain good quality for imaging the scene, using more resources. [0013] According to another exemplary embodiment, when the acquisition device has a lot of resources, the number of images to be acquired can be increased. [0014] According to another exemplary embodiment, when the acquisition device has few resources, for example a weak battery or a very busy processor, the number of images to be acquired can be reduced. [0015] Of course, these examples are in no way limiting. Other examples may combine several parameters, for example those indicated above, to adjust the number of images acquired during the image acquisition