PHP uploads and compresses images

This article mainly introduces the related information for PHP to upload and compress images, upload images and then scale the thumbnails according to the proportion, if you are interested, you can refer to the examples in this article to explain how to upload and compress PHP images and share them with you for your reference. the specific content is as follows:

Use three files

• Connect. php: connect to the database
• Test_upload.php: execute the SQL statement
• Upload_img.php: upload and compress images
  

The code for the three files is as follows:
Connect to the database:Connect. php

<?php$db_host = '';$db_user = '';$db_psw = '';$db_name = '';$db_port = '';$sqlconn=new mysqli($db_host,$db_user,$db_psw,$db_name);$q="set names utf8;";$result=$sqlconn->query($q);if (mysqli_connect_errno()) { printf("Connect failed: %s\n", mysqli_connect_error()); exit();}?>

Run the SQL statement test_upload.php.

<?phprequire ("connect.php");require ("upload_img.php");$real_img=$uploadfile; $small_img=$uploadfile_resize;$insert_sql = "insert into img (real_img,small_img) values (?,?)";$result = $sqlconn -> prepare($insert_sql);$result -> bind_param("ss", $real_img,$small_img);$result -> execute();?>

Upload and compress images:Upload_img.php

<? Php // Set the file storage directory $ uploaddir = "upfiles/"; // set the type of the file to be uploaded $ type = array ("jpg", "gif", "bmp ", "jpeg", "png"); // gets the file extension function fileext ($ filename) {return substr (strrchr ($ filename ,'. '), 1);} // function of generating random file name random ($ length) {$ hash = 'cr-'; $ chars = 'abcdefghijklmnopqrstuvwxyz0123456789abcdefghijklmnopqrstuvwxyz '; $ max = strlen ($ chars)-1; mt_srand (double) microtime () * 1000000); for ($ I = 0; $ I <$ le Ngth; $ I ++) {$ hash. = $ chars [mt_rand (0, $ max)];} return $ hash ;} $ a = strtolower (fileext ($ _ FILES ['filename'] ['name']); // Determine the file type if (! In_array (strtolower (fileext ($ _ FILES ['filename'] ['name']), $ type) {$ text = implode (",", $ type ); $ ret_code = 3; // file type error $ page_result = $ text; $ retArray = array ('ret _ code' => $ ret_code, 'page _ result' => $ page_result); $ retJson = json_encode ($ retArray); echo $ retJson; return ;} // Generate the target file named else {$ filename = explode (". ", $ _ FILES ['filename'] ['name']); do {$ filename [0] = random (10 ); // set the length of the random number $ name = implode (". ", $ filen Ame); // $ name1 = $ name. ". mcncc "; $ uploadfile = $ uploaddir. $ name;} while (file_exists ($ uploadfile); if (move_uploaded_file ($ _ FILES ['filename'] ['tmp _ name'], $ uploadfile )) {if (is_uploaded_file ($ _ FILES ['filename'] ['tmp _ name']) {$ ret_code = 1; // Upload failed} else {// Upload succeeded $ ret_code = 0 ;}}$ retArray = array ('ret _ code' => $ ret_code ); $ retJson = json_encode ($ retArray); echo $ retJson;} // compress the image $ uploaddir_resize = "upfiles_r Esize/"; $ uploadfile_resize = $ uploaddir_resize. $ name; // $ pic_width_max = 120; // $ pic_height_max = 90; // The above and the following annotations can be used in combination, allows the image to be compressed according to the calculated ratio $ file_type = $ _ FILES ["filename"] ['type']; function ResizeImage ($ uploadfile, $ maxwidth, $ maxheight, $ name) {// get the current image size $ width = imagesx ($ uploadfile); $ height = imagesy ($ uploadfile); $ I = 0.5; // Generate the thumbnail size if ($ width> $ maxwidth) | ($ height> $ maxheight) {/* $ widthratio = $ maxwidth/ $ Width; $ heightratio = $ maxheight/$ height; if ($ widthratio <$ heightratio) {$ ratio = $ widthratio;} else {$ ratio = $ heightratio ;} $ newwidth = $ width * $ ratio; $ newheight = $ height * $ ratio; */$ newwidth = $ width * $ I; $ newheight = $ height * $ I; if (function_exists ("imagecopyresampled") {$ uploaddir_resize = imagecreatetruecolor ($ newwidth, $ newheight); imagecopyresampled ($ uploaddir_resize, $ uploa Dfile, 0, 0, 0, 0, $ newwidth, $ newheight, $ width, $ height);} else {$ uploaddir_resize = imagecreate ($ newwidth, $ newheight ); imagecopyresized ($ uploaddir_resize, $ uploadfile, 0, 0, 0, 0, $ newwidth, $ newheight, $ width, $ height);} ImageJpeg ($ uploaddir_resize, $ name ); imageDestroy ($ uploaddir_resize);} else {ImageJpeg ($ uploadfile, $ name) ;}} if ($ _ FILES ["filename"] ['size']) {if ($ file_type = "image/p Jpeg "| $ file_type =" image/jpg "| $ file_type =" image/jpeg ") {// $ im = imagecreatefromjpeg ($ _ FILES [$ upload_input_name] ['tmp _ name']); $ im = imagecreatefromjpeg ($ uploadfile );} elseif ($ file_type = "image/x-png") {// $ im = imagecreatefrompng ($ _ FILES [$ upload_input_name] ['tmp _ name']); $ im = imagecreatefromjpeg ($ uploadfile);} elseif ($ file_type = "image/gif") {// $ im = imagecreatefromgif ($ _ FILES [$ uplo Ad_input_name] ['tmp _ name']); $ im = imagecreatefromjpeg ($ uploadfile);} else // Default jpg {$ im = imagecreatefromjpeg ($ uploadfile );} if ($ im) {ResizeImage ($ im, $ pic_width_max, $ pic_height_max, $ uploadfile_resize); ImageDestroy ($ im) ;}}?>

Change the information in connect. php and test_upload.php according to the actual situation.

The above is the PHP method for uploading and compressing images. I hope it will be helpful for you to learn php programming.