PHP 使用PHP调整图像大小

Posted 2021-05-15

<?php
function resampimagejpg( $forcedwidth, $forcedheight, $sourcefile, $destfile )
{
    $fw = $forcedwidth;
    $fh = $forcedheight;
    $is = getimagesize( $sourcefile );
    if( $is[0] >= $is[1] )
    {
        $orientation = 0;
    }
    else
    {
        $orientation = 1;
        $fw = $forcedheight;
        $fh = $forcedwidth;
    }
    if ( $is[0] > $fw || $is[1] > $fh )
    {
        if( ( $is[0] - $fw ) >= ( $is[1] - $fh ) )
        {
            $iw = $fw;
            $ih = ( $fw / $is[0] ) * $is[1];
        }
        else
        {
            $ih = $fh;
            $iw = ( $ih / $is[1] ) * $is[0];
        }
        $t = 1;
    }
    else
    {
        $iw = $is[0];
        $ih = $is[1];
        $t = 2;
    }
    if ( $t == 1 )
    {
        $img_src = imagecreatefromjpeg( $sourcefile );
        $img_dst = imagecreatetruecolor( $iw, $ih );
        imagecopyresampled( $img_dst, $img_src, 0, 0, 0, 0, $iw, $ih, $is[0], $is[1] );
        if( !imagejpeg( $img_dst, $destfile, 90 ) )
        {
            exit( );
        }
    }
    else if ( $t == 2 )
    {
        copy( $sourcefile, $destfile );
    }
}
?>