imagefilter

Applies a filter to an image

bool **imagefilter** GdImage $image int $filter  $args

applies the given filter
on the .

imagefilter``filter``image

filter can be one of the following:

  `filter`- : Reverses all colors of           the image.          `IMG_FILTER_NEGATE`

: Converts the image into grayscale by changing the red, green and blue components to their weighted sum using the same coefficients as the REC.601 luma (Y') calculation. The alpha components are retained. For palette images the result may differ due to palette limitations. IMG_FILTER_GRAYSCALE
: Changes the brightness of the image. Use to set the level of brightness. The range for the brightness is -255 to 255. IMG_FILTER_BRIGHTNESS``args
: Changes the contrast of the image. Use to set the level of contrast. IMG_FILTER_CONTRAST``args
: Like , except you can specify the color. Use , and in the form of , , and for the channel. The range for each color is 0 to 255. IMG_FILTER_COLORIZE``IMG_FILTER_GRAYSCALE``args``arg2``arg3``red``green``blue``arg4``alpha
: Uses edge detection to highlight the edges in the image. IMG_FILTER_EDGEDETECT
: Embosses the image. IMG_FILTER_EMBOSS
: Blurs the image using the Gaussian method. IMG_FILTER_GAUSSIAN_BLUR
: Blurs the image. IMG_FILTER_SELECTIVE_BLUR
: Uses mean removal to achieve a "sketchy" effect. IMG_FILTER_MEAN_REMOVAL
: Makes the image smoother. Use to set the level of smoothness. IMG_FILTER_SMOOTH``args
: Applies pixelation effect to the image, use to set the block size and to set the pixelation effect mode. IMG_FILTER_PIXELATE``args``arg2
: Applies scatter effect to the image, use and to define the effect strength and additionally to only apply the on select pixel colors. IMG_FILTER_SCATTER``args``arg2``arg3

args

  - : Brightness level.          `IMG_FILTER_BRIGHTNESS`

: Contrast level. IMG_FILTER_CONTRAST
: gd.value.red IMG_FILTER_COLORIZE
: Smoothness level. IMG_FILTER_SMOOTH
: Block size in pixels. IMG_FILTER_PIXELATE
: Effect substraction level. This must not be higher or equal to the addition level set with . IMG_FILTER_SCATTER``arg2

arg2

  - : gd.value.green          `IMG_FILTER_COLORIZE`

: Whether to use advanced pixelation effect or not (defaults to false). IMG_FILTER_PIXELATE
: Effect addition level. IMG_FILTER_SCATTER

arg3

  - : gd.value.blue          `IMG_FILTER_COLORIZE`

: Optional array indexed color values to apply effect at. IMG_FILTER_SCATTER

arg4

  - : Alpha channel, A value            between 0 and 127. 0 indicates completely opaque while 127 indicates            completely transparent.          `IMG_FILTER_COLORIZE`

return.success

Throws a if or would cause over-/underflow with the . ValueError``sub``plus``IMG_FILTER_SCATTER``filter

Voorbeeld: grayscale example

<?php
$im = imagecreatefrompng('dave.png');

if($im && imagefilter($im, IMG_FILTER_GRAYSCALE))
{
    echo 'Image converted to grayscale.';

    imagepng($im, 'dave.png');
}
else
{
    echo 'Conversion to grayscale failed.';
}
?>

Voorbeeld: brightness example

<?php
$im = imagecreatefrompng('sean.png');

if($im && imagefilter($im, IMG_FILTER_BRIGHTNESS, 20))
{
    echo 'Image brightness changed.';

    imagepng($im, 'sean.png');
}
else
{
    echo 'Image brightness change failed.';
}
?>

Voorbeeld: colorize example

<?php
$im = imagecreatefrompng('philip.png');

/* R, G, B, so 0, 255, 0 is green */
if($im && imagefilter($im, IMG_FILTER_COLORIZE, 0, 255, 0))
{
    echo 'Image successfully shaded green.';

    imagepng($im, 'philip.png');
}
else
{
    echo 'Green shading failed.';
}
?>

Voorbeeld: negate example

<?php
// Define our negate function so its portable for 
// php versions without imagefilter()
function negate($im)
{
    if(function_exists('imagefilter'))
    {
        return imagefilter($im, IMG_FILTER_NEGATE);
    }

    for($x = 0; $x < imagesx($im); ++$x)
    {
        for($y = 0; $y < imagesy($im); ++$y)
        {
            $index = imagecolorat($im, $x, $y);
            $rgb = imagecolorsforindex($index);
            $color = imagecolorallocate($im, 255 - $rgb['red'], 255 - $rgb['green'], 255 - $rgb['blue']);

            imagesetpixel($im, $x, $y, $color);
        }
    }

    return(true);
}

$im = imagecreatefromjpeg('kalle.jpg');

if($im && negate($im))
{
    echo 'Image successfully converted to negative colors.';

    imagejpeg($im, 'kalle.jpg', 100);
}
else
{
    echo 'Converting to negative colors failed.';
}
?>

Voorbeeld: pixelate example

<?php
// Load the PHP logo, we need to create two instances 
// to show the differences
$logo1 = imagecreatefrompng('./php.png');
$logo2 = imagecreatefrompng('./php.png');

// Create the image instance we want to show the 
// differences on
$output = imagecreatetruecolor(imagesx($logo1) * 2, imagesy($logo1));

// Apply pixelation to each instance, with a block 
// size of 3
imagefilter($logo1, IMG_FILTER_PIXELATE, 3);
imagefilter($logo2, IMG_FILTER_PIXELATE, 3, true);

// Merge the differences onto the output image
imagecopy($output, $logo1, 0, 0, 0, 0, imagesx($logo1) - 1, imagesy($logo1) - 1);
imagecopy($output, $logo2, imagesx($logo2), 0, 0, 0, imagesx($logo2) - 1, imagesy($logo2) - 1);

// Output the differences
header('Content-Type: image/png');
imagepng($output);
?>

Voorbeeld: scatter example

<?php
// Load the image
$logo = imagecreatefrompng('./php.png');

// Apply a very soft scatter effect to the image
imagefilter($logo, IMG_FILTER_SCATTER, 3, 5);

// Output the image with the scatter effect
header('Content-Type: image/png');
imagepng($logo);
?>

Opmerking: > The result of is always random. IMG_FILTER_SCATTER

imageconvolution

Vorige ← imagefilltoborder Volgende imageflip →

imagefilter

imagefilter

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