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Re: laying a grid on top of an image [message #15910 is a reply to message #15829]

Fri, 18 June 1999 00:00

Daniel Peduzzi
Messages: 29
Registered: June 1999

Junior Member

Daniel Peduzzi wrote in message <6Rja3.16621$AB2.371314@wbnws01.ne.mediaone.net>...
>
> Brian Nagy wrote in message <37684EAA.334F0A42@gte.net>...
>> Does anyone know of a quick easy way to put a grid of lines over top of
>> an existing image. I want to be able to specify the spacing on the grid
>> (in pixels), for example 40 columns by 100 rows, and have a grid placed
>> over top of an image which is already displayed in a window.
>>
>
>
> Could you alter the image before you display it in a window?
>
> If I had a 2D array called "my_image", and I wanted different spacings in the
> row and column directions, I'd do something like this:
>
> row_freq=20
> col_freq=40
>
> s=size(my_image)
> col_indices = indgen(s[1]/col_freq+1)
> row_indices = indgen(s[2]/row_freq+1)
>

Oops, forgot the multipliers. These lines should be

col_indices = indgen(s[1]/col_freq+1) * col_freq
row_indices = indgen(s[2]/row_freq+1) * row_freq

Dan Peduzzi
peduzzi@mediaone.net

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[Message index]

		laying a grid on top of an image By: Lazzar on Wed, 16 June 1999 00:00
		Re: laying a grid on top of an image By: Vapuser on Fri, 18 June 1999 00:00
		Re: laying a grid on top of an image By: Daniel Peduzzi on Fri, 18 June 1999 00:00
		Re: laying a grid on top of an image By: Daniel Peduzzi on Fri, 18 June 1999 00:00
		Re: laying a grid on top of an image By: mirko_vukovic on Thu, 17 June 1999 00:00

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