Опис

imagefilter(GdImage $image, int $filter, array|int|float|bool ...$args): bool

imagefilter() applies the given filter filter on the image.

Параметри

image

Об'єкт GdImage, що повертається однією з функцій створення зображення, такою як imagecreatetruecolor().

filter

filter can be one of the following:

IMG_FILTER_NEGATE: Reverses all colors of the image.
IMG_FILTER_GRAYSCALE: 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_BRIGHTNESS: Changes the brightness of the image. Use args to set the level of brightness. The range for the brightness is -255 to 255.
IMG_FILTER_CONTRAST: Changes the contrast of the image. Use args to set the level of contrast.
IMG_FILTER_COLORIZE: Like IMG_FILTER_GRAYSCALE, except you can specify the color. Use args, arg2 and arg3 in the form of red, green, blue and arg4 for the alpha channel. The range for each color is 0 to 255.
IMG_FILTER_EDGEDETECT: Uses edge detection to highlight the edges in the image.
IMG_FILTER_EMBOSS: Embosses the image.
IMG_FILTER_GAUSSIAN_BLUR: Blurs the image using the Gaussian method.
IMG_FILTER_SELECTIVE_BLUR: Blurs the image.
IMG_FILTER_MEAN_REMOVAL: Uses mean removal to achieve a "sketchy" effect.
IMG_FILTER_SMOOTH: Makes the image smoother. Use args to set the level of smoothness.
IMG_FILTER_PIXELATE: Applies pixelation effect to the image, use args to set the block size and arg2 to set the pixelation effect mode.
IMG_FILTER_SCATTER: Applies scatter effect to the image, use args and arg2 to define the effect strength and additionally arg3 to only apply the on select pixel colors.

args

IMG_FILTER_BRIGHTNESS: Brightness level.
IMG_FILTER_CONTRAST: Contrast level.
IMG_FILTER_COLORIZE: Значення червоного компонента.
IMG_FILTER_SMOOTH: Smoothness level.
IMG_FILTER_PIXELATE: Block size in pixels.
IMG_FILTER_SCATTER: Effect substraction level. This must not be higher or equal to the addition level set with arg2.

arg2

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

arg3

IMG_FILTER_COLORIZE: Значення синього компонента.
IMG_FILTER_SCATTER: Optional array indexed color values to apply effect at.

arg4

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

Значення, що повертаються

Повертає true у разі успіху або false в разі помилки.

Помилки/виключення

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

Журнал змін

Версія Опис

8.4.0 Now throws a ValueError if sub or plus would cause over-/underflow with the IMG_FILTER_SCATTER filter.

8.0.0 Тепер image має бути примірником GdImage. Раніше очікувався gd-resource.

7.4.0 Scatter support (IMG_FILTER_SCATTER) was added.

Версія	Опис
8.4.0	Now throws a ValueError if `sub` or `plus` would cause over-/underflow with the `IMG_FILTER_SCATTER` `filter`.
8.0.0	Тепер `image` має бути примірником GdImage. Раніше очікувався `gd`-resource.
7.4.0	Scatter support (`IMG_FILTER_SCATTER`) was added.

Приклади

Приклад #1 imagefilter() 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.';
}
?>

Приклад #2 imagefilter() 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.';
}
?>

Приклад #3 imagefilter() 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.';
}
?>

Приклад #4 imagefilter() 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.';
}
?>

Приклад #5 imagefilter() 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);
?>

Поданий вище приклад виведе щось схоже на:

Приклад #6 imagefilter() 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);
?>

Поданий вище приклад виведе щось схоже на:

Output of example : imagefilter() scatter

Примітки

Зауваження: The result of IMG_FILTER_SCATTER is always random.

Прогляньте також

imageconvolution() - Apply a 3x3 convolution matrix, using coefficient and offset