Linked Questions

3
votes
0answers
75 views

How to flatten a scanned image which is from scanner [duplicate]

I have a image from scanner: You can see that the right side of this paper is very flat, but it's curved in the left side. I think maybe I can detect the edge of this paper and then build some model ...
190
votes
2answers
61k views

QR Code in shopping cart handle

This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ...
50
votes
2answers
6k views

Detecting grid lines in a raster image

Motivation: Last October 7 there was a presidential election in Venezuela. Although the opposition saw an unprecedented increase in its votes, the government votes increased even more resulting in the ...
21
votes
2answers
5k views

How to remap a fisheye image?

I want to flatten a series of fisheye images by remapping them to a rectinlinear projection. To achieve this, I need to be able to remap the pixels of the image using fisheye correction formulas for ...
13
votes
3answers
1k views

Rotate a grid, made up of lines, so that it aligns with the xy axes

While working on an answer for another problem I hit upon one of my own. I took the image given in that question and cleaned it up so that I could detect the grid lines: ...
20
votes
2answers
11k views

How can I detect a rectangular region of interest in a picture?

Here is a downsampled input image I converted to greyscale. To select the rectangular region of interest we first preform preprocessing: ...
20
votes
1answer
3k views

How to extract metadata from an image of a business card?

I'm trying to digitize some documents, and I came across a very cool app called camscanner app which performs parallax transform and ocr very nicely, now I'm implementing it in mathematica... Given a ...
0
votes
1answer
478 views

What kind of algorithm can be used to map image coordinates to cylinder coordinates

I plan to flatten an images on curved surface(eg: jar or door knob) and I found a pretty good post which helps me a lot :)(link below). However, I still confuse on how to map image coordinate to ...
10
votes
0answers
211 views

How to segment rectangular photographs on a table?

Given an image of a table with photographs (take from any angle), I'm trying to extract the photographs and correctly align them into perfect rectangles. There are four steps to the algorithm: Detect ...
0
votes
0answers
170 views

Removing Perspective Distortion [duplicate]

Below is my input: I would like to remove perspective distortion from the image. Expected output below:
3
votes
0answers
133 views

Challenge: Calulating The Resulting 2D Image Behind A Lens [closed]

This is a tough question! I would like to calculate how an image (a real 2D photograph) looks if I place a lens at a certain distance d1 from it and I observe it at a certain distance d2. It is ...