17 Replies Latest reply: Sep 15, 2010 6:03 AM by MikeArmstrong

# Digitize Trace

Adapted from Valery ... July 01, 2009

jmG
• ###### Re: Digitize Trace

Jean,

I have just fell across this useful function.

Can you explain how this works and how the Matrix "M" is generated.

Mike

• ###### Re: Digitize Trace

>Can you explain how this works and how the Matrix "M" is generated.

Pallete Matrix + Button Picture

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Valery Ochkov wrote:

>Can you explain how this works and how the Matrix "M" is generated.

Pallete Matrix + Button Picture

Pallete Matrix???

How was the picture first created? Could this be used on graph extracted from books/standards?

Mike

• ###### Re: Digitize Trace

>Palette Matrix???

Sorry - Vector & Matrix toolbar!

>How was the picture first created?

By scanting a book, e.g.

• ###### Re: Digitize Trace

Valery Ochkov wrote:

>Palette Matrix???

Sorry - Vector & Matrix toolbar!

>How was the picture first created?

By scanting a book, e.g.

Valery,

I have just tried to replicate a graph I saved from the net, see attached worksheet.

As you can see the Mathcad graph looks nothing like the image, any suggestions?

Mike

• ###### Re: Digitize Trace

Cheers Valery,

What software have you used to extract the graphed area? In the worksheet you refer to "A spy quick trace extractor"

Mike

Message was edited by: MIke Armstrong

• ###### Re: Digitize Trace

MIke Armstrong wrote:

Jean,

I have just fell across this useful function.

Can you explain how this works and how the Matrix "M" is generated.

Mike

Mike,

The matrix M is created from the "Matrix clipboard operation". An essential procedure in image processing. If you don't have the twist, please let me know. There are several tools to digitize a graph. I use "Tracer" from Markus Karolweski, there is also the "Mathsoft Digitize". For very difficult cases, I use my own. In most applications, it is necessary to clean in Paint. The quality of digitizing depends upon the quality of the image. Too much distortion ==> recycle bin.

Jean

• ###### Re: Digitize Trace
Mike,

The matrix M is created from the "Matrix clipboard operation". An essential procedure in image processing. If you don't have the twist, please let me know. There are several tools to digitize a graph. I use "Tracer" from Markus Karolweski, there is also the "Mathsoft Digitize". For very difficult cases, I use my own. In most applications, it is necessary to clean in Paint. The quality of digitizing depends upon the quality of the image. Too much distortion ==> recycle bin.

Jean

Thanks Jean,

Have you extrapolated the points using Tracer?

Mike

• ###### Re: Digitize Trace

Thanks Jean,

Have you extrapolated the points using Tracer?

Mike

_________________________

Sorry Mike, I don't understand "extrapolate" in term of digitize ?

Jean

• ###### Re: Digitize Trace

Jean,

You managed to clean the graph and show the top section of the curve. I thought you had extrapolated to get those values - my mistake sorry.

Have you any tips on how to use the tracer software - Do you remove the grid lines using paint or tracer?

Mike

• ###### Re: Digitize Trace

Just went through that this morning.

> binarized

> edit in paint to remove interferences in the graph

> select the region to digitize

TTFN

• ###### Re: Digitize Trace

Eden Mei wrote:

Just went through that this morning.

> binarized

> edit in paint to remove interferences in the graph

> select the region to digitize

TTFN

Eden,

What does binarized mean?

So the curve gets selected and passed to the digitizing software?

It seems that the trace software can take the image or the extract the numerical data to Excel.

Mike

• ###### Re: Digitize Trace

Some of the curves I get are jpegs, which may have pretty ratty contrast to the background, so I generally try to grayscale the graph, and if its contrast is OK, I convert to a two-value color format, and then convert back, but I'm not sure whether Tracer will do two-value.

In any case, you get a graph with only black or white values. Then, in Paint, I eliminate most of the graph borders, leaving just enough to digitize the corners of the graph for proper scaling of the data. Then, you just drag/select the region to be digitized, and hit "Automatic" and it does its thing.

I only use Trace about once every 3 or 4 yrs, so it's always a learning experience when I use it, but I'm usually pressed for time, as well. There's probably better ways to do, but I'm loathe to try and figure them out, since I'll probably have forgotten them the next time I use the program.

TTFN

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Much appreciated.

Mike

• ###### Re: Digitize Trace

MIke Armstrong wrote:

Jean,

You managed to clean the graph and show the top section of the curve. I thought you had extrapolated to get those values - my mistake sorry.

Have you any tips on how to use the tracer software - Do you remove the grid lines using paint or tracer?

Mike

How I digitize :

1. sufficiently clean graph ==> Valery

2. zoned image-graph ==> Mathsoft digitizer

3. more ambiguous graphs ==> Tracer

4. RGB, Gray and any unfeasible graph ==> Hyper-Digitize [jmG]

5. specific value or "range value" ==> Mathcad EXTRACT(,,,) ... extract(,,,)

The Hyper-Digitize is manual only, works on the "mouse numeric pad".

APPEND to file. For images, a great lot of images processing can be

applied to help extract. Nothing special about using Tracer. Some web plot

have grid lines in gray, then no need to remove the lines. Generally, wise

to remove lines for the Mathsoft digitizer. Just too bad the "Hyper-Digitize"

can't be automated . The matter would be to code the "mouse-left-click".

That was suggested but ignored !

Cheers Mike, enjoy.

Jean

• ###### Re: Digitize Trace

Cheers for the explanation Jean.

Mike