Pixel Manipulations

[PyPK]

Does anyone know of a simple implementation for detecting straight line
..So something like if we have a 2D arary of pixel elements representing
a particular Image. How can we identify lines in this Image.
for example:

ary =
{{1,1,1,1,1},
{1,1,0,0,0},
{1,0,1,0,0},
{1,0,0,1,0},
{1,0,0,0,1}}
So if 'ary' represents pxl of an image which has a horizontal line(row
0),a vertical line(col 0) and a diagonal line(diagonal of ary). then
basically I want identify any horizontal or vertical or diagonal line
anywhere in the pxl array and return true if its composed of only lines
else false...

[Howard]

"PyPK" <su*******@gmail.com> wrote in message
news:11**********************@g44g2000cwa.googlegr oups.com...

Does anyone know of a simple implementation for detecting straight line
.So something like if we have a 2D arary of pixel elements representing
a particular Image. How can we identify lines in this Image.
for example:

ary =
{{1,1,1,1,1},
{1,1,0,0,0},
{1,0,1,0,0},
{1,0,0,1,0},
{1,0,0,0,1}}
So if 'ary' represents pxl of an image which has a horizontal line(row
0),a vertical line(col 0) and a diagonal line(diagonal of ary). then
basically I want identify any horizontal or vertical or diagonal line
anywhere in the pxl array and return true if its composed of only lines
else false...

Not really a c++ language question, but...

Loop through that row or column (or diagonal), and if any cell is 0, return
false. Otherwise, return true if the loop completes.

Implement that in c++ code, and if you have trouble, show us your attempt at
the code, let us know exactly which part is the problem, and what that
problem is (i.e., you get a compiler error, a run-time error, or simply
incorrect behavior).

-Howrd

[Victor Bazarov]

PyPK wrote:

Does anyone know of a simple implementation for detecting straight line
.So something like if we have a 2D arary of pixel elements representing
a particular Image. How can we identify lines in this Image.
for example:

ary =
{{1,1,1,1,1},
{1,1,0,0,0},
{1,0,1,0,0},
{1,0,0,1,0},
{1,0,0,0,1}}
So if 'ary' represents pxl of an image which has a horizontal line(row
0),a vertical line(col 0) and a diagonal line(diagonal of ary). then
basically I want identify any horizontal or vertical or diagonal line
anywhere in the pxl array and return true if its composed of only lines
else false...

Do you have a C++ _language_ question?

V

[ajitho]

Hi:
Look up the "Hough transform"

[PyPK]

was trying to understand it..is there any demo code that could
demonstrate its behaviour

[Victor Bazarov]

PyPK wrote:

was trying to understand it..is there any demo code that could
demonstrate its behaviour

There probably is. Try googling for it.

Again, any particular algorithms for doing something particular are
not really on topic here. Try a different newsgroup.

V

[mlimber]

PyPK wrote:

was trying to understand it..is there any demo code that could
demonstrate its behaviour

The key word for this concept is "edge detection". Any book on image
processing will cover it, and I'm sure you can find some code online.
If you have a C++ question, post it here. Otherwise, you should
probably post to sci.image.processing or comp.dsp.

Cheers! --M