如何使用 php imagefilter 创建带有 jpg 图像的矢量图像

Question

请帮我在下面创建这样的矢量图像，我尝试使用图像过滤灰度，但是它没有创建我想要的深黑色，所以如果你可以帮助我在 PHP 中创建这样的深黑色矢量，那就是很棒。

这是我之前尝试过的下面的代码，它创建了一个矢量，但它是灰色而不是黑色

来自这张图片

this

到图片

this

我的代码是

if($effect){

            imagefilter($dst_img, IMG_FILTER_GRAYSCALE);
             
            
           //imagefilter($dst_img, IMG_FILTER_CONTRAST, -100);
        }

我的完整代码是

    function createThumbnail($imageName,$newWidth,$newHeight,$effect)
    {
        $uploadDir="assets/front/collage/images/9fd0c8fe";
        $path = $uploadDir . '/' . $imageName;

        $mime = getimagesize($path);

        if($mime['mime']=='image/png'){ $src_img = imagecreatefrompng($path); }
        if($mime['mime']=='image/jpg'){ $src_img = imagecreatefromjpeg($path); }
        if($mime['mime']=='image/jpeg'){ $src_img = imagecreatefromjpeg($path); }
        if($mime['mime']=='image/pjpeg'){ $src_img = imagecreatefromjpeg($path); }

        $old_x = imageSX($src_img);
        $old_y = imageSY($src_img);

        if($old_x > $old_y)
        {
            $thumb_w    =   $newWidth;
            $thumb_h    =   $old_y/$old_x*$newWidth;
        }

        if($old_x < $old_y)
        {
            $thumb_w    =   $old_x/$old_y*$newHeight;
            $thumb_h    =   $newHeight;
        }

        if($old_x == $old_y)
        {
            $thumb_w    =   $newWidth;
            $thumb_h    =   $newHeight;
        }

        
        $dst_img        =   ImageCreateTrueColor($thumb_w,$thumb_h);

        imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);

        if($effect){

            imagefilter($dst_img, IMG_FILTER_GRAYSCALE);
             
            
           //imagefilter($dst_img, IMG_FILTER_CONTRAST, -100);
        }
        // New save location
        //$new_thumb_loc = $moveToDir . $imageName;

        if($mime['mime']=='image/png'){ $result = imagepng($dst_img); }
        if($mime['mime']=='image/jpg'){ $result = imagejpeg($dst_img); }
        if($mime['mime']=='image/jpeg'){ $result = imagejpeg($dst_img); }
        if($mime['mime']=='image/pjpeg'){ $result = imagejpeg($dst_img); }
        
        

        imagedestroy($dst_img);
        imagedestroy($src_img);
        return $result;
    }

Answer 1

这对我有用：

<?php

createThumbnail('test.png',50,50,true);
function createThumbnail($imageName,$newWidth,$newHeight,$effect)
    {
        $uploadDir="assets/front/collage/images/9fd0c8fe";
        $path = $uploadDir . '/' . $imageName;

        $mime = getimagesize($path);

        if($mime['mime']=='image/png'){ $src_img = imagecreatefrompng($path); }
        if($mime['mime']=='image/jpg'){ $src_img = imagecreatefromjpeg($path); }
        if($mime['mime']=='image/jpeg'){ $src_img = imagecreatefromjpeg($path); }
        if($mime['mime']=='image/pjpeg'){ $src_img = imagecreatefromjpeg($path); }

        $old_x = imagesx($src_img);
        $old_y = imagesy($src_img);

        if($old_x > $old_y)
        {
            $thumb_w    =   $newWidth;
            $thumb_h    =   $old_y/$old_x*$newWidth;
        }

        if($old_x < $old_y)
        {
            $thumb_w    =   $old_x/$old_y*$newHeight;
            $thumb_h    =   $newHeight;
        }

        if($old_x == $old_y)
        {
            $thumb_w    =   $newWidth;
            $thumb_h    =   $newHeight;
        }
        
        $dst_img        =   imagecreatetruecolor($thumb_w,$thumb_h);
        
        imagecopyresampled($dst_img,$src_img,0,0,0,0,$thumb_w,$thumb_h,$old_x,$old_y);



        if($effect){

            imagefilter($dst_img, IMG_FILTER_GRAYSCALE);
            imagefilter($dst_img, IMG_FILTER_CONTRAST, -100);
             
        }
        // New save location
        //$new_thumb_loc = $moveToDir . $imageName;
        header('Content-Type: ' . $mime['mime']); //Changed for my test
        if($mime['mime']=='image/png'){ $result = imagepng($dst_img); }
        if($mime['mime']=='image/jpg'){ $result = imagejpeg($dst_img); }
        if($mime['mime']=='image/jpeg'){ $result = imagejpeg($dst_img); }
        if($mime['mime']=='image/pjpeg'){ $result = imagejpeg($dst_img); }
            return $result;
    }