Dear Simon,
after having inspected the images you've posted to the Forum, I
understand that you are interested in the point of intersection of what
you call the "superficial fascia"-line and the "true fasciular length"-line.
It is not clear to me how you define the latter line, i.e. apart from
its inclination, that is given by the structure, how do you position the
line?
For the time being let's assume both lines are correctly positioned,
then you need the coordinates of two points on each line.
Here are the processing steps that work for me:
0.
From the ImageJ "Plugins"-Menu Select "New > Macro"
Paste the following code to the "Macro.txt"-window
// Begin line intersection coordinates macro
run( "Set Measurements...", " redirect=None decimal=3" );
roiManager("multi-measure measure_all");
selectWindow( "ROI Manager" );
run( "Close" );
x = newArray( 4 );
y = newArray( 4 );
for ( i = 0; i< 4; i++ ) {
x[i] = getResult( "X", i );
y[i] = getResult( "Y", i );
}
selectWindow( "Results" );
run( "Close" );
//superficial fascia line
b_1 = ( y[0] - y[1] ) / ( x[0] - x[1] );
a_1 = y[0] - b_1 * x[0];
//true fasciular length line
b_2 = ( y[2] - y[3] ) / ( x[2] - x[3] );
a_2 = y[2] - b_2 * x[2];
//intersection coordinates
xx = ( a_1 - a_2 ) / ( b_2 - b_1 );
yy = a_1 + b_1 * xx;
print( "Intersection Coordinates:" );
print( "x = " + xx + ", y = " + yy );
exit();
// End
1.
Select the "Point"-tool from the tool bar
2.
Click on a point of the "superficial fascia"-line, then type Cmd-t
3.
Click on a different point of the "superficial fascia"-line, then type Cmd-t
4.
Click on a point of the "true fasciular length"-line, then type Cmd-t
5.
Click on a different point of the "true fasciular length"-line, then
type Cmd-t
6.
Bring the "Macro.txt"-window with the code to the front and typs Cmd-r
7.
A "Log"window opens showing the desired coordinates.
Please note that a negative x-coordinate means that the intersection is
(to the left) outside the image canvas.
In fact you don't really need to draw the lines, you only need to set
the four points that define the lines accordingly.
HTH
Herbie
:::::::::::::::::::::::::::::::::::::::::
Am 06.01.17 um 02:40 schrieb Simon Locke:
> Dear Herbie,
>
> Thank you for your patience.
>
> I have manage to upload the images, definition and measurement goal using
> the upload function. I hope this makes it clearer
>
> Regards
> Simon
>
> Dr Simon Locke
> MBBS BMedSc FACSP FFSEM(UK) FRACGP
> Sport and Exercise Medicine Physician
> Bendigo Orthopaedic and Sports Medicine Clinic
> 176 Barnard st., Bendigo, Victoria, 3550
>
> P:613 5442 5288 F:613 54425399 W:sportmovementcentre.com
>
> -----Original Message-----
> From: Herbie [mailto:
[hidden email]]
> Sent: Friday, 6 January 2017 6:12 AM
> To: Simon Locke;
[hidden email]
> Subject: Re: measuring fasciular length inside/outside image - posted
> previously now has image
>
> Dear Simon,
>
> you write:
>
> "If it is not possible in ImageJ to measure outside the image"...
>
> ...but you don't tell us what exactly you would like to measure and what the
> meaning of the yellow line is and how it is constructed.
>
> It is no problem to enlarge the image canvas. But does it help with your
> processing that I don't understand?
>
> And please use terms that can be understood by people who are not in your
> field.
>
> Tell us how you construct the lines and how you would like to determine the
> intersection etc.
>
> If you have the definition of the lines, you can determine their
> intersection without drawing them outside the image. Just do the math.
>
> Best
>
> Herbie
>
> ::::::::::::::::::::::::::::::::::::::::
> Am 05.01.17 um 19:59 schrieb Simon Locke:
>> Good morning Herbie.
>>
>> Thanks for replying. As you realised this is a cross post mainly
>> because I could not "copy and paste" images into the blog. This is a
>> direct consequence of my capacities - sorry.
>>
>> However, If it is not possible in ImageJ to measure outside the image
>> as the yellow line indicates, then it is wasting everyone's time to
>> look at the next question which is drawing 2 lines that intersect
>> outside the image. Angles are easy but I have not been able to
>> measure a line that starts inside the image and extends beyond the
>> image.
>>
>> So if it is simply not possible to measure then I need to find another
>> way to measure FL in muscles - trigonometry is well described as well
>> as using multiple US transducers. But if it is possible then I may
>> need to ask the next question which is simply multiple lines
>> (done) and determining the intersection point outside the image.
>>
>> I am limited to using the program as I do not have script skills.
>>
>> Measuring FL requires tracing the fascicles along its length until it
>> intersects with the aponeurosis either deep or superficial depending
>> on choice. There are a number of assumptions here but the error is
>> minimal and consistent.
>>
>> Again thanks for your reply. I do enjoy reading the enormous material
>> that comes with this community even outside my field.
>>
>> Regards Simon
>>
>> Simon Locke Sport and Exercise Medicine Physician 176 Barnard st.,
>> Bendigo P: 61354425288 W: www.sportmovementcentre.com Sent from my
>> iPad
>>
>>> On 6 Jan 2017, at 12:52 am, Herbie <
[hidden email]> wrote:
>>>
>>> Good day Simon Locke,
>>>
>>> this is a cross-post from the Forum.
>>>
>>> Evidently you could post some images here but without careful
>>> description they appear worthless.
>>>
>>> If you want help, then please be more specific about the desired task
>>> and about the example images.
>>>
>>> Best
>>>
>>> Herbie
>>>
>>> :::::::::::::::::::::::::::::::::::::::::::
>>>> Am 05.01.17 um 03:32 schrieb Simon Locke:
>>>>
>>>>
>>>> Hi, Is it possible using ImageJ to measure length of a fascicle and
>>>> continue the measurement outside the image?
>>>>
>>>> Sometimes the fascicles sampled during US scanning extend beyond the
>>>> image. It is possible to measure this using trigonometric
>>>> principles. I would prefer to be able to measure the FL in real time
>>>> from its intercept with either superficial or deep aponeurosis. I
>>>> have attached a copy of a relevant muscle.
>>>>
>>>> I have tried to add a relevant image but cannot do so here. I would
>>>> appreciate any thoughts. Thank you for looking and I will repeat
>>>> this in email with image
>>>>
>>>> Regards Simon Locke
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Dr Simon Locke
>>>>
>>>> MBBS BMedSc FACSP FFSEM(UK) FRACGP
>>>>
>>>> Sport and Exercise Medicine Physician
>>>>
>>>> Bendigo Orthopaedic and Sports Medicine Clinic
>>>>
>>>> 176 Barnard st., Bendigo, Victoria, 3550
>>>>
>>>>
>>>>
>>>> P:613 5442 5288 F:613 54425399
>>>> W:sportmovementcentre.com
>>>>
>>>>
>>>>
>>>>
>>>> -- ImageJ mailing list:
http://imagej.nih.gov/ij/list.html>>>>
>>>
>>> -- ImageJ mailing list:
http://imagej.nih.gov/ij/list.html>>
>>
>
>
--
ImageJ mailing list:
http://imagej.nih.gov/ij/list.html
Locked
image001.gif (128 bytes) Download Attachment