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Re: laying a grid on top of an image [message #15913 is a reply to message #15829]

Fri, 18 June 1999 00:00

Daniel Peduzzi
Messages: 29
Registered: June 1999

Junior Member

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)

my_image[col_indices, *]=255
my_image[*, row_indices]=255

tvlct, [255], [0], [0], 255 ; Make last colormap entry "red"
tv, my_image

This would display a red grid, with the above spacings, over the image.

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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