how to detect text box in an image?

[ShivaGupta]

want to detect or cut text box in this image.........plz hep me

[Firemankurt]

Not much experience in this area but I have used "imagemagick" with PHP and I did find a possible lead for you:

 

Searching Google for "php imagemagick ocr"

 

Found:

 

http://stackoverflow.com/questions/11978986/ocr-getting-text-from-image-using-tesseract-3-0-and-imagemagick-6-6-5

[jcbones]

This is why Captcha's are getting harder for users to see.  No help from me.

[ShivaGupta]

  On 12/30/2013 at 11:19 PM, jcbones said:

This is why Captcha's are getting harder for users to see.  No help from me.

its not a captcha n i want only Get The Text  Box Position in image not text....so plz help

[Barand]

Start at the top left and look for an occurrence of many contiguous horizontal white pixels.

Then work back from bottom right looking for same.

[ShivaGupta]

  On 12/31/2013 at 8:16 AM, Barand said:

Start at the top left and look for an occurrence of many contiguous horizontal white pixels.

Then work back from bottom right looking for same.

is their any example?

[Barand]

  On 1/4/2014 at 1:04 PM, ShivaGupta said:

is their any example?

Not that I know of, you may have to roll up your sleeves and dive in.

 

It should just require a couple of nested for() loops and use of imagecolorat to test each pixel

[Barand]

I tried it with the png image you posted. It fount the top left OK but when working up from the bottom of the image it couldn't find a long chain of white pixels until it reached row 7 (should have found one at row 47). The only thing I can think of is there may be some anti-aliasing and not all pixels in the text background are a perfect white.

 

I saved the image as a a gif file to reduce the color resolution and it worked fine giving

left top (20, 0)
right bottom (462, 47)

gif image attached

 

Here's the code

<?php

$im = imagecreatefromgif('shiva1.gif');
$iw = imagesx($im);
$ih = imagesy($im);
$wht = imagecolorresolve($im,0xFF,0xFF,0xFF);

$top = $left = $bottom = $right = -1;

/***************************************
* search from top left                 *
****************************************/
for ($y=0; $y<$ih; $y++) {
    for ($x=0; $x<$iw; $x++) {
        if (countRight($im, $x, $y, $iw, $wht) >= 100) {
            $top = $y;
            $left = $x;
            break 2;
        }
    }
}
echo "left top ($left, $top)<br>";

/***************************************
* search from bottom right             *
****************************************/
for ($y=$ih-1; $y>0; $y--) {
    for ($x=$iw-1; $x>0; $x--) {
        if (countLeft($im, $x, $y, $wht) >= 100) {
            $bottom = $y;
            $right = $x;
            break 2;
        }
    }
}
echo "right bottom ($right, $bottom)";


/*******************************************************
* functions to count horizontal white pixels           *
********************************************************/
function countRight($im, $x, $y, $iw, $wht)
{
    $k = 0;
    while ($x < $iw) {
        if (imagecolorat($im, $x, $y)!=$wht) {
            return $k;
        }
        ++$k;
        ++$x;
    }
    return $k;
}

function countLeft($im, $x, $y, $wht)
{
    $k = 0;
    while ($x > 0) {
        if (imagecolorat($im, $x, $y)!=$wht) {
            return $k;
        }
        ++$k;
        --$x;
    }
    return $k;
}
?>

[ShivaGupta]

ok sir Thanks a lot ....

and again here i want to save new picture with detected pixeles left top (20, 0)
right bottom (462, 47)

 

 

i tried myself  but i am new in php so no luck plz help again.........Thank you

[Barand]

I am not sure what you mean

[ShivaGupta]

  On 1/7/2014 at 5:28 PM, Barand said:

I am not sure what you mean

cut that detected part n save as this picture

[Barand]

Delete the 2 lines that echo the left-top and right-bottom coordinates then add this code

/************************************************
* Create image of the text area                 *
*************************************************/
$im2 = imagecreate($right-$left, $bottom-$top);
imagecopy($im2, $im, 0, 0, $left, $top, $right-$left, $bottom-$top);
// output image
header("Content-type: image/gif");
imagegif($im2);
imagedestroy($im);
imagedestroy($im2);

[GetFreaky]

  On 12/31/2013 at 8:16 AM, Barand said:

Start at the top left and look for an occurrence of many contiguous horizontal white pixels.

Then work back from bottom right looking for same.

 

 

 Does PHP allow to iterate pixel by pixel... like this for example

for($y=0;$y<=$height;$y++)
{
  
  for($x=0;$x<=$width;$x++)
  {
    // pixel manipulation here
  }

}

Whenever I worked with images with php, it was always built-in functions, not sure how flexible the libraries actually are. From what I remember they had a layer of abstraction and you can invoke functions to do certain things to a group of pixels, don't know about pixel by pixel

[Barand]

GetFreaky

 

See code in #8 above

[GetFreaky]

  On 1/7/2014 at 7:46 PM, Barand said:

GetFreaky

 

See code in #8 above

 

Completely missed it,  thanks.

 

Sorry for going off-topic a little there.

[ShivaGupta]

@

Barand    Thanks A Lot Sir ...Code Working Fine.....

[Barand]

I managed to get the correct result on the original PNG image by adjusting the image brightness (line 5 in code attached)

textarea.phpFetching info...