ImageJ

Problem with drawLine

_‹ Previous Topic Next Topic _›

Classic

List

Threaded

2 messages Options

Luis Isaac Ramos Garcia

Problem with drawLine

Dear Colleges;

First, I am new with ImageJ and its macro language so sorry if this
is a not interesting.

I would like to draw a line in a centered image, i.e. the origin of
the coordinates is not the left upper corner instead is more or less the
center of the image.
The center is at (1182,963) in a 2369x1928 image.

When I tried the following lines the macro does not work:

setColor(255, 0, 0);
setLineWidth(1);
i=0;

x1=round((i-14)*(10/0.17));
y1=-750;
x2=x1;
y2=750;
drawLine(x1,y1,x2,y2);

Instead if I take the origin of the coordinates the left upper
corner the macro works:

setColor(255, 0, 0);
setLineWidth(1);
i=0;

x1=round((i-14)*(10/0.17));
y1=-750;
x2=x1;
y2=750;
drawLine(x1,y1,x2,y2);

But the if I change the 14 in the third line by 13....:

setColor(255, 0, 0);
setLineWidth(1);
i=0;

x1=round((i-13)*(10/0.17));
y1=-750;
x2=x1;
y2=750;
drawLine(x1,y1,x2,y2);

It does not work again.

At the end I suppose that there is a concept fail on the use of
drawLine but I don't know.

PD: I use i the code because in the next step I want to draw 29
lines in a 1cm step

Dear Colleges;

First, I am new with ImageJ and its macro language so sorry if this
is a not interesting.

I would like to draw a line in a centered image, i.e. the origin of
the coordinates is not the left upper corner instead is more or less the
center of the image.
The center is at (1182,963) in a 2369x1928 image.

When I tried the following lines the macro does not work:

setColor(255, 0, 0);
setLineWidth(1);
i=0;

x1=round((i-14)*(10/0.17));
y1=-750;
x2=x1;
y2=750;
drawLine(x1,y1,x2,y2);

Instead if I take the origin of the coordinates the left upper
corner the macro works:

setColor(255, 0, 0);
setLineWidth(1);
i=0;

x1=round((i-14)*(10/0.17));
y1=-750;
x2=x1;
y2=750;
drawLine(x1,y1,x2,y2);

But the if I change the 14 in the third line by 13....:

setColor(255, 0, 0);
setLineWidth(1);
i=0;

x1=round((i-13)*(10/0.17));
y1=-750;
x2=x1;
y2=750;
drawLine(x1,y1,x2,y2);

It does not work again.

At the end I suppose that there is a concept fail on the use of
drawLine but I don't know.

PD: I use "i" the code because in the next step I want to draw 29
lines, i. e. I would like to use these sentences in a for loop

Many Thanks,

--
Dr Luis Isaac Ramos Garcia
Departamento de Oncologia
Clinica Universidad de Navarra
Facultad de Medicina,Universidad de Navarra
Av. Pio XII nº36, 31008 Pamplona, Spain
Fax: +34 948255500
TEL: +34 948255400 (Ext. 4924)
E-mail: [hidden email]
Web Page: http://www.cun.es

BenTupper

Re: Problem with drawLine

Hi,

In version 1.44d it appears that drawLine accepts pixel coordinates
where the origin is at the upper left regardless how how the origin is
specified in the properties. I don't know if that is intentional or
not and the online docs don't mention it. One way around that might be
something like the following...

//newImage("Test", "8-bit Black", 1182, 963, 1);
w = getWidth();
h = getHeight();
xc = w/2;
yc = h/2;
run("Properties...", "pixel_height=1 pixel_width=1 origin="+xc+","+yc);

n = 30;
dx = w/n;
dy = h/n;
for (i = 0; i <n; i++){
y = i * dy;
drawLine(0, y, w, y);
}

Cheers,
Ben

On Jul 20, 2010, at 4:34 AM, Luis Isaac Ramos Garcia wrote:

> Dear Colleges;
>
> First, I am new with ImageJ and its macro language so sorry if
> this is a not interesting.
>
> I would like to draw a line in a centered image, i.e. the origin
> of the coordinates is not the left upper corner instead is more or
> less the center of the image.
> The center is at (1182,963) in a 2369x1928 image.
>
> When I tried the following lines the macro does not work:
> setColor(255, 0, 0);
> setLineWidth(1);
> i=0;
> x1=round((i-14)*(10/0.17));
> y1=-750;
> x2=x1;
> y2=750;
> drawLine(x1,y1,x2,y2);
>
> Instead if I take the origin of the coordinates the left upper
> corner the macro works:
>
> setColor(255, 0, 0);
> setLineWidth(1);
> i=0;
> x1=round((i-14)*(10/0.17));
> y1=-750;
> x2=x1;
> y2=750;
> drawLine(x1,y1,x2,y2);
>
> But the if I change the 14 in the third line by 13....:
>
> setColor(255, 0, 0);
> setLineWidth(1);
> i=0;
> x1=round((i-13)*(10/0.17));
> y1=-750;
> x2=x1;
> y2=750;
> drawLine(x1,y1,x2,y2);
>
> It does not work again.
> At the end I suppose that there is a concept fail on the use of
> drawLine but I don't know.
>
> PD: I use i the code because in the next step I want to draw 29
> lines in a 1cm step
>
> Dear Colleges;
>
> First, I am new with ImageJ and its macro language so sorry if
> this is a not interesting.
>
> I would like to draw a line in a centered image, i.e. the origin
> of the coordinates is not the left upper corner instead is more or
> less the center of the image.
> The center is at (1182,963) in a 2369x1928 image.
>
> When I tried the following lines the macro does not work:
> setColor(255, 0, 0);
> setLineWidth(1);
> i=0;
> x1=round((i-14)*(10/0.17));
> y1=-750;
> x2=x1;
> y2=750;
> drawLine(x1,y1,x2,y2);
>
> Instead if I take the origin of the coordinates the left upper
> corner the macro works:
>
> setColor(255, 0, 0);
> setLineWidth(1);
> i=0;
> x1=round((i-14)*(10/0.17));
> y1=-750;
> x2=x1;
> y2=750;
> drawLine(x1,y1,x2,y2);
>
> But the if I change the 14 in the third line by 13....:
>
> setColor(255, 0, 0);
> setLineWidth(1);
> i=0;
> x1=round((i-13)*(10/0.17));
> y1=-750;
> x2=x1;
> y2=750;
> drawLine(x1,y1,x2,y2);
>
> It does not work again.
> At the end I suppose that there is a concept fail on the use of
> drawLine but I don't know.
>
> PD: I use "i" the code because in the next step I want to draw 29
> lines, i. e. I would like to use these sentences in a for loop
>
>
> Many Thanks,
>
> --
> Dr Luis Isaac Ramos Garcia
> Departamento de Oncologia
> Clinica Universidad de Navarra
> Facultad de Medicina,Universidad de Navarra
> Av. Pio XII nº36, 31008 Pamplona, Spain
> Fax: +34 948255500
> TEL: +34 948255400 (Ext. 4924)
> E-mail: [hidden email]
> Web Page: http://www.cun.es