How to get autocrops offset and size?

问题

The php-function imagecropauto() can automaticly crop an image.

and I guess its do some calculations and send the offset and size as paramters to the imagecrop() function.

The size value I can get from the returned image, but is there someway to get the offset value?

回答1:

Here is an ugly solution, by swaping the color of the botom-right corner.
Is there a easier way?

function autocrop_range($image)
{
    $org_size = array(imagesx($image), imagesy($image));
    $croped = imagecropauto($image, IMG_CROP_SIDES);
    if(!$croped)
    {
        return FALSE;
    }
    $croped_size = array(imagesx($croped), imagesy($croped));
    if($org_size == $croped_size)
    {
        return FALSE;
    }
    imagedestroy($croped);
    $copy = imagecrop($image, array('x' => 0, 'y' => 0, 'width' => $org_size[0], 'height' => $org_size[1]));
    $corner_color = imagecolorat($copy, $org_size[0] - 1, $org_size[1] - 1);
    $r = ($corner_color >> 16) & 0xFF;
    $g = ($corner_color >> 8) & 0xFF;
    $b = ($corner_color) & 0xFF;
    $other_color = imagecolorallocate($copy, $r ^ 0x80, $r ^ 0x80, $r ^ 0x80);
    imagesetpixel($copy, $org_size[0] - 1, $org_size[1] - 1, $other_color); // force botom to stay uncroped
    imagesetpixel($copy, $org_size[0] - 1, $org_size[1] - 2, $other_color); // force right to stay uncroped
    $corner_croped = imagecropauto($copy, IMG_CROP_SIDES);
    imagedestroy($copy);
    $corner_croped_size = array(imagesx($corner_croped), imagesy($corner_croped));
    imagedestroy($corner_croped);

    return array('x' => ($org_size[0] - $corner_croped_size[0]), 'y' => ($org_size[1] - $corner_croped_size[1]), 'width' => $croped_size[0], 'height' => $croped_size[1]);
}

来源：https://stackoverflow.com/questions/40584754/how-to-get-autocrops-offset-and-size

标签

php