imagefilltoborder

(PHP 4, PHP 5, PHP 7)

imagefilltoborder — 区域填充到指定颜色的边界为止

说明

bool imagefilltoborder ( resource $image , int $x , int $y , int $border , int $color )

imagefilltoborder() 从 x，y（图像左上角为 0, 0）点开始用 color 颜色执行区域填充，直到碰到颜色为 border 的边界为止。【注：边界内的所有颜色都会被填充。如果指定的边界色和该点颜色相同，则没有填充。如果图像中没有该边界色，则整幅图像都会被填充。】

User Contributed Notes

php at corzoogle dot com 27-Jun-2005 09:08


pritm (.a.t.) mail (.d.0.t.) ru, your jpg black areas aren't entirely black, look *real* closely at it! so the fill will "seep through". the solution is simple, use a lossless background image format. replace this line..



<?

$im = imagecreatefrompng ('map-back.png');

?>



try it with this version of your image..



http://corz.org/public/images/demo/map-back.png

(the colours may be slightly different, just a quick conversion in my regular image viewer)



as you can see, it works perfectly..

http://corz.org/public/images/demo/filled.jpg



;o)

(or

Henrik Nyh 24-Jun-2005 10:26


Reply to pritm (.a.t.) mail (.d.0.t.) ru below.



I had a similar problem and solved it thus:



I had to reduce the number of colors on the image I was using. It appeared to be a black and white map, but contained about 50 shades of almost black and almost white. I reduced this to two colors only (also going from JPG to GIF) so that the borders as well as the areas to be filled each were of a consistent shade.



Additionally, it did not work when I specified border colors as black (0,0,0), even though they seem to be of this exact shade in the map file. Instead, I used ImageColorAt() to pick the border color, and now everything seems to work.



Image: http://henrik.nyh.se/dump/map/europe.gif

In action: http://henrik.nyh.se/dump/map/map.html



Source:



<?php



$map = "europe.gif";



$img = ImageCreateFromGIF($map);



// Colors

$border = ImageColorAt ($img, 416, 111);  // Get color of borders - apparently (0,0,0) won't work

$red = ImageColorAllocate($img, 255, 0, 0); 

$green = ImageColorAllocate($img, 0, 255, 0);



// Fill

ImageFillToBorder($img, 440, 100, $border, $red);  // Sweden

ImageFillToBorder($img, 250, 290, $border, $green);  // Great Britain



// Output image as PNG

header("Content-type: image/png");

ImagePNG($img); 

ImageDestroy($img);  // Free memoryu



?>

sbuchanan at datadiver dot net 11-May-2005 12:08


edrad's pseudo-sphere is pretty nice, but a few tweeks really improve it.  (writing out the image header so a browser actually understands it and calling imagedestroy() so we clean up memory are nice things to do, too).  Try drawing it at twice the size and then resampling it down.  Takes more CPU, but it forces antialiasing, creating a smooth arc.  Also, render it at diameter = (width - 1) * 2.  Taking one pixel off the outside keeps it off the image edge, eliminating those ugly flat spots.  Render it on white first so you can really see the edge, then switch back to the cool grey...



Oh, and use imagecreatetruecolor instead of imagecreate if you have it available.



I agree that imageellipse is easier, though.  Actually, I generate rounded corners with drop-shadows for CSS with imagefilledarc (kind of a blend of the two)  Use imagefilledellipse if drawing the whole thing, use imagefilledarc if only drawing part of it (like a corner).  If you use the 'filled' functions you can skip imagefilltoborder altogether :P



Anyway, try this for a smoother image:



<?php



  $requested_width = 300;

  $render_width = ($requested_width * 2) - 1; // -1 to back away from edge, removing flat spot

  $center = $render_width / 2;  

  $colordivs = 255 / $center;

  $im_scratch = @imagecreate($render_width, $render_width);



  //$back_color = imagecolorallocate($im_scratch, 20, 30, 40);  // try it with white so you can really see the edge first..

  $back_color = imagecolorallocate($im_scratch, 255, 255, 255);



  imagefill($im_scratch, 0, 0, $back_color);



  for ($i = 0; $i <= $center; $i++) {

    $diametre = $render_width - 2 * $i;

    $el_color = imagecolorallocate($im_scratch, $i * $colordivs, 0, 0);

    imageellipse($im_scratch, $center, $center, $diametre, $diametre, $el_color);

    imagefilltoborder($im_scratch, $center, $center, $el_color, $el_color);

  }



  // resample down, causes antialiasing, nice smooth curve! 

  $im = @imagecreatetruecolor($requested_width, $requested_width); 

  imagecopyresampled($im, $im_scratch, 0, 0, 0, 0, $requested_width, $requested_width, $render_width, $render_width);



  header ("Content-type: image/png");

  imagepng($im);

  ImageDestroy($im);

  ImageDestroy($im_scratch);



?>

admin at worldlanguages dot tk 10-Sep-2004 11:54


In the example below, for those with newer GD versions, it makes more sense to replace:



imagearc($im, $center, $center, $diametre, $diametre, 0, 360, $el_color);



with:



imageellipse($im, $center, $center, $diametre, $diametre, $el_color);



This is obviously simpler.

edrad at wanadoo dot fr 11-Jun-2003 02:02


Very useful to build a pseudo-sphere with a color gradient...



<?php

 $width = 300;

 $center = $width / 2;

 $colordivs = 255 / $center;

 $im = @imagecreate($width, $width);

 $back_color = imagecolorallocate($im, 20, 30, 40);

 imagefill($im, 0, 0, $back_color); 

 for ($i = 0; $i <= $center; $i++)

 {

     $diametre = $width - 2 * $i;

    $el_color = imagecolorallocate($im, $i * $colordivs, 0, 0);

    imagearc($im, $center, $center, $diametre, $diametre, 0, 360, $el_color);

    imagefilltoborder($im, $center, $center, $el_color, $el_color);

 }

 imagepng($im);

?>



Dark Skull Software

http://www.darkskull.net

ecofarm at mullum dot com dot au 25-Jan-2001 07:18


Great for getting that rounded button look we see a lot of at php.net ... try this sample. (remember to change png to whatever image format your version of php supports)





<?php





    Header ("Content-type: image/png");








      ///// create canvas  /////





    $im = ImageCreate (80, 25);





  //define colors.. first color declared is set as background





    $blue  = ImageColorAllocate ($im, 0, 0, 255);


    $white  = ImageColorAllocate ($im, 255, 255, 255);





      // draw semi-circle arcs at each end





    ImageArc($im, 12, 12, 23, 26, 90, 270, $white);


    ImageArc($im, 67, 12, 23, 26, 270, 90, $white);





      // fill ends outside arcs with color





    ImageFillToBorder ($im, 0, 0, $white, $white);


    ImageFillToBorder ($im, 79, 0, $white, $white);





      // create the image





    ImagePng ($im);





      // destroy the image to free memory





    ImageDestroy ($im);


?>