gd

问题 I want to loop through all the pixels of an image, find the rgba value of that pixel, and do something with those pixels. Example Say I have an image that's 100x100 pixels. I want to find the value of each one of those pixels with the function I already made: function getPixel($image, $x, $y) { $colors = imagecolorsforindex($image, imagecolorat($image, $x, $y)); $inrgba = 'rgba(' . $colors['red'] . ',' . $colors['green'] . ',' . $colors['blue'] . ',' . $colors['alpha'] . ')'; return $inrgba;

问题 The following code uses the SimpleImage library I have a function that gets a pixel from an image: function getPixel($x, $y) { $colors = imagecolorsforindex($this->image, imagecolorat($this->image, $x, $y)); $n[0] = $colors['red']; $n[1] = $colors['green']; $n[2] = $colors['blue']; $str = "#"; for($x=0;$x < 3; $x++){ $n[$x] = intval($n[$x],10); if (is_nan($n[$x])) return "00"; $n[$x] = max(0, min($n[$x],255)); $bam = "0123456789ABCDEF"; $str .= $bam{($n[$x]-$n[$x]%16)/16} . $bam{$n[$x]%16}; }

问题 I want to watermark an image and save it. here is the code i am using for it. Here it is outputting the image and is storing that output to the file. I want to save it without outputting it. // Load the stamp and the photo to apply the watermark to $stamp = imagecreatefrompng('stamp.png'); $im = imagecreatefromjpeg('proverbs.jpeg'); // Set the margins for the stamp and get the height/width of the stamp image $marge_right = 10; $marge_bottom = 10; $sx = imagesx($stamp); $sy = imagesy($stamp);

问题 I am trying to take a Base64 encoded image from the database and save it to a file. For whatever reason, when I try using imagecreatefromstring & imagepng the image is completely black. I have tried many different approaches, but I still end up with a black box. Below is my best attempt to get it to work. Any ideas? Thank you so much in advance! $thefile = base64_decode($strImage); $img = imagecreatefromstring($thefile); if($img !== false) { header('Content-Type: image/png'); imagepng($img);

问题 I'm trying to re-save an already created JPEG as a progressive jpg. Basically, on the front end I have some JS that crops an image, and outputs a base64 image JPEG. Once it is passed to the PHP script, I create it as a regular JPEG file, like so: $largeTEMP = explode(',', $_POST['large']); $large = base64_decode($largeTEMP[1]); file_put_contents('../../images/shows/'.$dirName.'/large.jpg', $large); I'm wanting this jpg image to be progressive, so I was looking around and found the PHP

问题 When running Page Speed in Google Chrome it suggests to optimize/compress the images. These images are mostly uploaded by users, so I would need to optimize them during uploading. What I find about optimizing jpeg images with php is something like using the following GD functions: getimagesize() imagecreatefromjpeg() imagejpeg() Since I am resizing the images after upload I'm already pulling the image through these functions and in addition I use imagecopyresampled() after imagecreatefromjpeg

问题 how is it possible to save my image, created with gd, as an png-8? it saves as gif with transparent channel well - but I want to use png-8. Best Regards, Beerweasle 回答1: Using imagesavealpha() and a transparent bg color should do the trick... Based on dfilkovi's code: <?php // Create a new true color image $im = new imagecreatetruecolor(100, 100); // Fill with alpha background $alphabg = imagecolorallocatealpha($im, 0, 0, 0, 127); imagefill($im, 0, 0, $alphabg); // Convert to palette-based

问题 Please see this question: PHP GD Use one image to mask another image, including transparency - The rules around here say for users to create new questions rather than revisit old ones and ask for support I've been working with this script to enable transparent masking - the (possible) difference being that the source image has transparency, but it seems like the code below only works if the input PNGs have no transparency. Can someone have a look and see if I'm doing anything wrong? What I'm

问题 I've installed the GD Library on my Apache just now, and it seems that my script below doesn't work. I'm trying to add a layer "play.png" to a youtube video thumbnail (http://img.youtube.com/vi/VIDEOID/default.jpg) I've tried it with many different videoID's but the image doesn't load. There is a message that the graphic couldn't be opened because it contains errors. I'm opening the file with postimage.php?v=7yV_JtFnIwo http://img.youtube.com/vi/7yV_JtFnIwo/default.jpg opens correctly too...

问题 I'm trying to output multiline text with GD+PHP but can't get it working. my php knowledge is really basic. here's the code, any idea on how to output 2 or 3 lines of text? $theText = (isset($_GET['caption']))? stripslashes($_GET['caption']) :''; imagettftext($baseImage, $textSize, $textAngle, $textXposition, $textYposition, $textColor, $fontName, $theText); 回答1: imagettftext($baseImage, $textSize, $textAngle, $textXposition, $textYposition, $textColor, $fontName, $theText); imagettftext(