Automatic scanning of document stack with a camera
View Patent ↗Automatically scanning multiple document sheets with a camera includes receiving a video stream while the camera is pointed at the multiple document sheets, detecting presence of a first top page of the multiple document sheets based on the video stream, taking a still photograph of the first top page in response to detecting presence of the first top page, detecting presence of a second top page based on the video stream by confirming that the second top page is different from the first top page and by waiting a predetermined amount of time for an image of the second top page to stabilize, and taking a still photograph of the second top page in response to detecting presence of the second top page. Detecting the pages may include determining that the camera is pointing at the stack of documents and a detected page is not obstructed.
1. A method for scanning pages of a multi-page document, the method comprising:
at an electronic device with a camera:
capturing, by the camera, a series of images;
determining, using one or more subsets of the series of images, wherein at least one of the one or more subsets of the series of images includes a plurality of images, whether a respective page of the multi-page document meets capture criteria, wherein the determination that the respective page of the multi-page document meets the capture criteria includes:
determining that the respective page of the multipage document meets stability criteria, and
determining that a view of the respective page of the multipage document meets visibility criteria, including determining that the respective page is not obstructed by another page;
in accordance with a determination that the respective page of the multi-page document meets the capture criteria, storing a respective image captured by the camera as a first stored page image of the multi-page document; and
in accordance with a determination that the respective page of the multi-page document does not meet the capture criteria:
capturing, by the camera, at least one additional image of the multi-page document, and
repeating the determining, using the one or subsets of the series of images, whether the respective page of the multi-page document meets the capture criteria.
2. The method of claim 1 , wherein the respective image captured by the camera is an image from the series of images.
3. The method of claim 1 , wherein the series of images are frames of a video stream.
4. The method of claim 1 , wherein the determination that a view of the respective page of the multipage document meets the visibility criteria includes at least one of:
determining that a contrast between the respective page and a background meets contrast criteria; and
determining that one or more identified page boundaries meet page boundary criteria.
5. The method of claim 1 , wherein the determination that the respective page of the multi-page document meets the capture criteria includes determining that the respective page is distinct from a previously stored page image of a previous page of the multi-page document.
6. The method of claim 1 , wherein the determination that the respective page of the multipage document meets the stability criteria includes determining that a position of the respective page within the image frame of a subset of the images does not move by more than a threshold amount.
7. The method of claim 1 , wherein the determination that the respective page of the multipage document meets the stability criteria includes determining that, during a predetermined period of time, movement of the respective page does not increase beyond a threshold amount.
8. The method of claim 7 , wherein the predetermined period of time is at least five times a sample period from a first time at which first image of the series of images was captured to a second time at which a subsequent image of the series of images was captured.
9. The method of claim 1 , including, in accordance with a determination that the respective page of the multi-page document does not meet the capture criteria, displaying, via a di splay of the electronic device, status information.
10. The method of claim 9 , wherein the status information includes a captured image from the series of images.
11. The method of claim 1 , including, prior to capturing the series of images, generating an empty image data instance for storing page images of the multi-page document.
12. A non-transitory computer readable storage medium storing one or more programs, the one or more programs comprising instructions, which, when executed by an electronic device with a camera, cause the system to:
capture, by the camera, a series of images;
determine, using one or more subsets of the series of images, wherein at least one of the one or more subsets of the series of images includes a plurality of images, whether a respective page of the multi-page document meets capture criteria, wherein the determination that the respective page of the multi-page document meets the capture criteria includes:
determining that the respective page of the multipage document meets stability criteria, and
determining that a view of the respective page of the multipage document meets visibility criteria, including determining that the respective page is not obstructed by another page;
in accordance with a determination that the respective page of the multi-page document meets the capture criteria, store a respective image captured by the camera as a first stored page image of the multi-page document; and
in accordance with a determination that the respective page of the multi-page document does not meet the capture criteria:
capture, by the camera, at least one additional image of the multi-page document, and
repeat the determining, using the one or subsets of the series of images, whether the respective page of the multi-page document meets the capture criteria.
13. The non-transitory computer-readable storage medium of claim 12 , wherein the determination that the respective page of the multi-page document meets the capture criteria includes determining that the respective page is distinct from a previously stored page image of a previous page of the multi-page document.
14. The non-transitory computer-readable storage medium of claim 12 , wherein the determination that the respective page of the multipage document meets stability criteria includes determining that, during a predetermined period of time, movement of the respective page does not increase beyond a threshold amount.
15. An electronic device, comprising:
memory;
one or more processors;
a camera; and
one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for:
capturing, by the camera, a series of images;
determining, using one or more subsets of the series of images, wherein at least one of the one or more subsets of the series of images includes a plurality of images, whether a respective page of the multi-page document meets capture criteria, wherein the determination that the respective page of the multi-page document meets the capture criteria includes:
determining that the respective page of the multipage document meets stability criteria, and
determining that a view of the respective page of the multipage document meets visibility criteria, including determining that the respective page is not obstructed by another page;
in accordance with a determination that the respective page of the multi-page document meets the capture criteria, storing a respective image captured by the camera as a first stored page image of the multi-page document; and
in accordance with a determination that the respective page of the multi-page document does not meet the capture criteria:
capturing, by the camera, at least one additional image of the multi-page document; and
repeating the determining, using the one or subsets of the series of images, whether the respective page of the multi-page document meets the capture criteria.
16. The electronic device of claim 15 , wherein:
the electronic device includes a display; and
the one or more programs include instructions for, in accordance with a determination that the respective page of the multi-page document does not meet the capture criteria, displaying, via the display, status information.
17. The electronic device of claim 16 , wherein the status information includes a captured image from the series of images.