GET the index of the closest color to the specified color in an image file.
<?php
int imagecolorclosest( GdImage $image,
int $red,
int $green,
int $blue )
where,
$image = The image identifier
$red = The value of red component color
$green = The value of green component color
$blue = The value of blue component color
?>
EXERCISE
<?php
echo 'PHP VERSION: ' . PHP_VERSION . '<br><br>';
$lang = 'en';
$tst_img01 = "gif/GIF 009 01.gif";
$exact_col_img01 = "gif/GIF 009 01-exact color.gif";
$closest_col_img01 = "gif/GIF 009 01-closest color.gif";
$cs_red01 = 204;
$cs_green01 = 204;
$cs_blue01 = 0;
echo $tst_img01; ?>
<br><br><img src="<?php echo $tst_img01; ?>"
alt="<?php echo $tst_img01; ?>" width="400"><br><br>
<?php
$im01 = imagecreatefromgif($tst_img01);
$ndx_exc_pal01 =
imagecolorexact($im01, $cs_red01, $cs_green01, $cs_blue01);
if ($ndx_exc_pal01 == -1)
{
$im01s = imagecreate(imagesx($im01), 30);
imagecolorallocate($im01s, $cs_red01, $cs_green01, $cs_blue01);
imagegif($im01s, $exact_col_img01);
$en = 'The reported color is not part of the image!';
echo $exact_col_img01 . '<br><br>';
echo '<img src="' . $exact_col_img01
. '" alt="' . $exact_col_img01 . '"' . ' width="400">';
echo '<br><br>RGB = ( ' . $cs_red01 . ', ' . $cs_green01
. ', ' . $cs_blue01 . ' )<br>' . $$lang ;
$en = 'Index = ' . $ndx_exc_pal01;
echo '<br>' . $$lang;
$ndx_closest_pal01 =
imagecolorclosest($im01, $cs_red01, $cs_green01, $cs_blue01);
$color_ndx_closest_pal01 =
imagecolorsforindex( $im01, $ndx_closest_pal01);
$ct_red01 = $color_ndx_closest_pal01['red'];
$ct_green01 = $color_ndx_closest_pal01['green'];
$ct_blue01 = $color_ndx_closest_pal01['blue'];
$im01t = imagecreate(imagesx($im01), 30);
imagecolorallocate($im01t, $ct_red01, $ct_green01, $ct_blue01);
imagegif($im01t, $closest_col_img01);
$en = '<br>The closest color!';
echo '<br><br><br>' . $closest_col_img01;
echo '<br><br><img src="' . $closest_col_img01
. '" alt="' . $closest_col_img01 . '"' . ' width="400">';
echo '<br><br>RGB = ( ' . $ct_red01 . ', ' . $ct_green01
. ', ' . $ct_blue01 . ' ) ' . $$lang;
$en = 'Index = ' . $ndx_closest_pal01;
echo '<br>' . $$lang . '';
}
else
{
$im01s = imagecreate(imagesx($im01), 30);
imagecolorallocate($im01s,$cs_red01, $cs_green01, $cs_blue01);
imagegif($im01s, $exact_col_img01);
echo '* ' . $exact_col_img01 . ' ';
$en = '<br><br>
* The reported color is part of the image!
<br>';
echo '<br>* RGB = ( ' . $cs_red01 . ', ' . $cs_green01
. ', ' . $cs_blue01 . ' )' . $$lang;
echo '<br><img src="' . $exact_col_img01
. '" alt="' . $exact_col_img01 . '"' . ' width="400">';
$en = '<br>* Index = ' . $ndx_exc_pal01;
echo '<br>' . $$lang . '<br>';
}
?>
EXERCISE
<?php
echo 'PHP VERSION: ' . PHP_VERSION . '<br><br>';
$lang = 'en';
$tst_img02 = "gif/GIF 014 01 white-red.gif";
$exact_col_img02 = "gif/GIF 014 01 white-red-exact color.gif";
$closest_col_img02 = "gif/GIF 014 01 white-red-closest color.gif";
$cs_red02 = mt_rand(0, 255);
$cs_green02 = mt_rand(0, 255);
$cs_blue02 = mt_rand(0, 255);
/*
// Try this values for the color to see the difference
$cs_red02 = 0;
$cs_green02 = 0;
$cs_blue02 = 254;
*/
echo $tst_img02; ?>
<br><br><img src="<?php echo $tst_img02; ?>"
alt="<?php echo $tst_img02; ?>"><br><br>
<?php
$im02 = imagecreatefromgif($tst_img02);
$ndx_exc_pal02 =
imagecolorexact($im02,
$cs_red02, $cs_green02, $cs_blue02);
if ($ndx_exc_pal02 == -1)
{
$im02s = imagecreate(imagesx($im02), 30);
imagecolorallocate($im02s,
$cs_red02, $cs_green02, $cs_blue02);
imagegif($im02s, $exact_col_img02);
$en = 'The reported color is not part of the image!';
echo $exact_col_img02 . '<br><br>';
echo '<img src="' . $exact_col_img02
. '" alt="' . $exact_col_img02 . '"' . '>';
echo '<br><br>RGB = ( ' . $cs_red02 . ', ' . $cs_green02
. ', ' . $cs_blue02 . ' )<br>' . $$lang;
$en = 'Palette Index = ' . $ndx_exc_pal02;
echo '<br>' . $$lang;
$ndx_closest_pal02 =
imagecolorclosest($im02,
$cs_red02, $cs_green02, $cs_blue02);
$color_ndx_closest_pal02 =
imagecolorsforindex( $im02, $ndx_closest_pal02);
$ct_red02 = $color_ndx_closest_pal02['red'];
$ct_green02 = $color_ndx_closest_pal02['green'];
$ct_blue02 = $color_ndx_closest_pal02['blue'];
$im02t = imagecreate(imagesx($im02), 30);
imagecolorallocate($im02t,
$ct_red02, $ct_green02, $ct_blue02);
imagegif($im02t, $closest_col_img02);
$en = '<br>The closest color!';
echo '<br><br><br>' . $closest_col_img02;
echo '<br><br><img src="' . $closest_col_img02
. '" alt="' . $closest_col_img02 . '"' . '>';
echo '<br><br>RGB = ( ' . $ct_red02 . ', ' . $ct_green02
. ', ' . $ct_blue02 . ' ) ' . $$lang;
$en = 'Palette Index = ' . $ndx_closest_pal02;
echo '<br>' . $$lang . '';
}
else
{
$im02s = imagecreate(imagesx($im02), 30);
imagecolorallocate($im02s,
$cs_red02, $cs_green02, $cs_blue02);
imagegif($im02s, $exact_col_img02);
echo '* ' . $exact_col_img02 . ' ';
$en = '<br><br>
* The reported color is part of the image palette!
<br>';
echo '<br>* RGB = ( ' . $cs_red02 . ', ' . $cs_green02
. ', ' . $cs_blue02 . ' )' . $$lang;
echo '<br><img src="' . $exact_col_img02
. '" alt="' . $exact_col_img02 . '"' . '>';
$en = '<br>* Palette Index = ' . $ndx_exc_pal02;
echo '<br>' . $$lang . '<br>';
}
?>
EXERCISE
<?php
echo 'PHP VERSION: ' . PHP_VERSION . '<br><br>';
$lang = 'en';
$tst_img03 = "jpeg/JPEG 019 03 white-red.jpg";
$exact_col_img03 = "jpeg/JPEG 019 03 white-red-exact color.jpg";
$closest_col_img03 = "jpeg/JPEG 019 03 white-red-closest color.jpg";
$cs_red03 = mt_rand(0, 255);
$cs_green03 = mt_rand(0, 255);
$cs_blue03 = mt_rand(0, 255);
/*
// Try this values for the color to see the difference
$cs_red03 = 0;
$cs_green03 = 0;
$cs_blue03 = 254;
*/
echo $tst_img03; ?>
<br><br><img src="<?php echo $tst_img03; ?>"
alt="<?php echo $tst_img03; ?>"><br><br>
<?php
$im03 = imagecreatefromjpeg($tst_img03);
$ndx_exc_pal03 =
imagecolorexact($im03, $cs_red03, $cs_green03, $cs_blue03);
if ($ndx_exc_pal03 == -1)
{
$im03s = imagecreate(imagesx($im03), 30);
imagecolorallocate($im03s, $cs_red03, $cs_green03, $cs_blue03);
imagegjpeg($im03s, $exact_col_img03);
$en = 'The reported color is not part of the image!';
echo 'RGB = ( ' . $cs_red03 . ', ' . $cs_green03
. ', ' . $cs_blue03 . ' )<br>' . $$lang . '<br><br>';
echo $exact_col_img03 . '<br><br>';
echo '<img src="' . $exact_col_img03
. '" alt="' . $exact_col_img03 . '"' . '>';
$en = 'Index = ' . $ndx_exc_pal03;
echo '<br><br>' . $$lang;
$ndx_closest_pal03 =
imagecolorclosest($im03, $cs_red03, $cs_green03, $cs_blue03);
$color_ndx_closest_pal03 =
imagecolorsforindex( $im03, $ndx_closest_pal03);
$ct_red03 = $color_ndx_closest_pal03['red'];
$ct_green03 = $color_ndx_closest_pal03['green'];
$ct_blue03 = $color_ndx_closest_pal03['blue'];
$im03t = imagecreate(imagesx($im03), 30);
imagecolorallocate($im03t, $ct_red03, $ct_green03, $ct_blue03);
imagejpeg($im03t, $closest_col_img03);
$en = '<br>The closest color!';
echo '<br><br><br><br><br>RGB = ( ' . $ct_red03 . ', ' . $ct_green03
. ', ' . $ct_blue03 . ' )' . $$lang . '<br><br>';
echo $closest_col_img03;
echo '<br><br><img src="' . $closest_col_img03
. '" alt="' . $closest_col_img03 . '"' . '>';
$en = 'Index = ' . $ndx_closest_pal03;
echo '<br><br>' . $$lang . '';
}
else
{
$im03s = imagecreate(imagesx($im03), 30);
imagecolorallocate($im03s, $cs_red03, $cs_green03, $cs_blue03);
imagejpeg($im03s, $exact_col_img03);
echo '<br>' . $exact_col_img03 . '<br><br>';
$en = '<br>The reported color is part of the image!<br>';
echo '<img src="' . $exact_col_img03
. '" alt="' . $exact_col_img03 . '"' . '>';
echo '<br><br>RGB = ( ' . $cs_red03 . ', ' . $cs_green03
. ', ' . $cs_blue03 . ' )' . $$lang;
$en = 'Index = ' . $ndx_exc_pal03;
echo $$lang . '<br>';
}
?>
EXERCISE
<?php
// RUN this code several times
echo 'PHP VERSION: ' . PHP_VERSION . '<br><br>';
$lang = 'en';
$tst_img04 = "png/PNG 033 04-test image.png";
$exact_col_img04 = "png/PNG 033 04-exact color.png";
$closest_col_img04 = "png/PNG 033 04-closest color.png";
$cs_red04 = mt_rand(0, 255);
$cs_green04 = mt_rand(0, 255);
$cs_blue04 = mt_rand(0, 255);
$xf04 = 20;
$yf04 = 20;
$im04 = imagecreate(384, 288);
$blue04 = imagecolorallocate($im04, 0, 0, 255);
imagefill($im04, $xf04, $yf04, $blue04);
imagepng($im04, $tst_img04);
echo $tst_img04; ?><br><br>
<img src="<?php echo $tst_img04; ?>"
alt="<?php echo $tst_img04; ?>"
title="<?php echo $tst_img04; ?>">
<?php
$ndx_exc_pal04 =
imagecolorexact($im04, $cs_red04, $cs_green04, $cs_blue04);
if ($ndx_exc_pal04 == -1)
{
$im04s = imagecreate(imagesx($im04), 30);
imagecolorallocate($im04s, $cs_red04, $cs_green04, $cs_blue04);
imagepng($im04s, $exact_col_img04);
$en = 'The reported color is not part of the image!';
echo '<br><br>' . $exact_col_img04 . '<br><br>';
echo '<img src="' . $exact_col_img04
. '" alt="' . $exact_col_img04 . '"' . '>';
echo '<br><br>RGB = ( ' . $cs_red04 . ', ' . $cs_green04
. ', ' . $cs_blue04 . ' )<br>' . $$lang;
$en = '<br>Index = ' . $ndx_exc_pal04;
echo $$lang;
$ndx_closest_pal04 =
imagecolorclosest($im04, $cs_red04, $cs_green04, $cs_blue04);
$color_ndx_closest_pal04 =
imagecolorsforindex( $im04, $ndx_closest_pal04);
$ct_red04 = $color_ndx_closest_pal04['red'];
$ct_green04 = $color_ndx_closest_pal04['green'];
$ct_blue04 = $color_ndx_closest_pal04['blue'];
$im04t = imagecreate(imagesx($im04), 30);
imagecolorallocate($im04t, $ct_red04, $ct_green04, $ct_blue04);
imagepng($im04t, $closest_col_img04);
$en = '<br>The closest color!';
echo '<br><br>' . $closest_col_img04;
echo '<br><br><img src="' . $closest_col_img04
. '" alt="' . $closest_col_img04 . '"' . '>';
echo '<br><br>RGB = ( ' . $ct_red04 . ', ' . $ct_green04
. ', ' . $ct_blue04 . ' )' . $$lang;
$en = '<br>Index = ' . $ndx_closest_pal04;
echo $$lang . '';
}
else
{
$im04s = imagecreate(imagesx($im04), 30);
imagecolorallocate($im04s, $cs_red04, $cs_green04, $cs_blue04);
imagepng($im04s, $exact_col_img04);
echo '<br><br>* ' . $exact_col_img04 . ' ';
$en = '<br>* The reported color is part of the image!
<br>';
echo '<br>* RGB = ( ' . $cs_red04 . ', ' . $cs_green04
. ', ' . $cs_blue04 . ' )' . $$lang;
echo '<br><img src="' . $exact_col_img04
. '" alt="' . $exact_col_img04 . '"' . '>';
$en = '<br>* Index = ' . $ndx_exc_pal04;
echo '<br>' . $$lang . '<br>';
}
?>
