Linked Questions

51
votes
5answers
10k views

How can I extract data points from a black and white image?

Consider the following graph (source): Is there any way to extract the data points from this image in a semi-automatic way? I have seen, and tried the methods suggested in this question, but they did ...
37
votes
2answers
3k views

How to make a curve selectable from a scaned image and convert it to a list of coordinates

I have a scanned image (binary-ized): Is there any way to reduce one of these curved lines (full or dotted) to a series of its coordinates (e.g., sampling interval of 0.01 on x-axis)? I've read ...
26
votes
6answers
15k views

Problem with NonlinearModelFit

I'm having trouble with a non-linear fit: fit = NonlinearModelFit[data, y0 + A Sin[\[Pi] (x - xc)/w], {y0, xc, A, w}, x] where ...
20
votes
1answer
3k views

Finding the area, algebraic curve and jaggedness of an arbitrary shape

I start with a photograph of a shape (physically made by the flow of a liquid into another), of which I can extract the border, manually or using Mathematica's feature detect feature : Using the ...
14
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: ...
14
votes
2answers
1k views

How to detect loops in a vector field?

Given a vector field and I'd like to detect if there are streamlines in closed patterns. For example, if the input is a vector field like this: ...
13
votes
2answers
551 views

Extracting data from analog screen photograph

I'm using an analog profilometer from the 1970s and need a way to digitize the data and the only way is through a photograph. I've searched but all I could find was how to extract data from computer ...
5
votes
2answers
3k views

Best fit equation from a scanned image

I am trying to extract a curve from a scanned graph and find a best fit equation. For example, starting from: How could one find an equation starting from the image file ?
5
votes
2answers
311 views

How to find analytical expresion for data from image

I need to find an analytical expression for the data collected from an image. I found a relevant topic on how to extract the data in here. But there are some differences in my question. I have this ...
5
votes
1answer
184 views

Finding position of text returned with TextRecognize

I am trying to extract data from images (using some of the methods presented in [1524]), and would like to have a way to selectively cover/remove text from axes and legends. ...
5
votes
1answer
875 views

Computing the distance between two curves obtained from image data?

I've got some image data that I've binarized. The image contains two curves, from which I'd like to compute the distance between (eventually computing an average radius for each point in the picture)....
4
votes
2answers
498 views

How can I get the solubility value of nitrogen in water at 10 degrees Celsius with Mathematica?

How can I get the solubility value of nitrogen in water at 10 °C with Mathematica? The site engineering toolbox dot com gives graphs of such values, but I want the numerical value. Related thread on ...
4
votes
2answers
1k views

How to copy Coordinates of "Get Coordinates" in Figure?

I am trying to reproduce the answer here about Recovering data points from an image. I click the figure and press "Get Coordinates". I would like to copy the four coordinates by CTRL-C and then paste ...
3
votes
3answers
4k views

How to do deconvolution in spectrum with some peaks?

For example, I have the next spectrum: I've seen the next question ["How to perform a multi-peak fitting?"][2] but not answer to my question. I want deconvolution the spectrum to obtain three peaks (...
3
votes
1answer
882 views

extract data from a graph image

How do I convert the following image graph into data (if possible into function)? I checked this answer and found that my problem is grid and plot have same color.

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