Code for generating proportional thumbnails for uploading images in php

Upload an image file using php and generate a scaled thumbnail. For more information, see.

The Code is as follows:

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<? Php Function _ UPLOADPIC ($ upfile, $ maxsize, $ updir, $ newname = 'date '){ If ($ newname = 'date ') $ Newname = date ("Ymdhis"); // use date as the file name $ Name = $ upfile ["name"]; $ Type = $ upfile ["type"]; $ Size = $ upfile ["size"]; $ Tmp_name = $ upfile ["tmp_name"]; Switch ($ type ){ Case 'image/pjpeg ': Case 'image/jpeg ': $ Extend = ". jpg "; Break; Case 'image/gif ': $ Extend = ". gif "; Break; Case 'image/png ': $ Extend = ". png "; Break; } If (emptyempty ($ extend )){ Echo ("warning! Only the image type can be uploaded: GIF. JPG "); Exit (); } If ($ size> $ maxsize ){ $ Maxpr = $ maxsize/1000; Echo ("warning! The size of the uploaded image cannot exceed ". $ maxpr." K! "); Exit (); } If (move_uploaded_file ($ tmp_name, $ updir. $ newname. $ extend )){ Return $ updir. $ newname. $ extend; } }   Function show_pic_scal ($ width, $ height, $ picpath ){ $ Imginfo = GetImageSize ($ picpath ); $ Imgw = $ imginfo [0]; $ Imgh = $ imginfo [1];   $ Ra = number_format ($ imgw/$ imgh), 1); // Aspect Ratio $ Ra2 = number_format ($ imgh/$ imgw), 1); // Aspect Ratio     If ($ imgw> $ width or $ imgh> $ height ){ If ($ imgw> $ imgh ){ $ NewWidth = $ width; $ NewHeight = round ($ newWidth/$ ra );   } Elseif ($ imgw <$ imgh ){ $ NewHeight = $ height; $ NewWidth = round ($ newHeight/$ ra2 ); } Else { $ NewWidth = $ width; $ NewHeight = round ($ newWidth/$ ra ); } } Else { $ NewHeight = $ imgh; $ NewWidth = $ imgw; } $ Newsize [0] = $ newWidth; $ Newsize [1] = $ newHeight;   Return $ newsize; }       Function getImageInfo ($ src) { Return getimagesize ($ src ); } /** * Create an image and return the resource type * @ Param string $ src image path * @ Return resource $ im: returned resource Type ***/ Function create ($ src) { $ Info = getImageInfo ($ src ); Switch ($ info [2]) { Case 1: $ Im = imagecreatefromgif ($ src ); Break; Case 2: $ Im = imagecreatefromjpeg ($ src ); Break; Case 3: $ Im = imagecreatefrompng ($ src ); Break; } Return $ im; } /** * Thumbnail Main Function * @ Param string $ src image path * @ Param int $ w thumbnail width * @ Param int $ h thumbnail height * @ Return mixed return the thumbnail path ***/   Function resize ($ src, $ w, $ h) { $ Temp = pathinfo ($ src ); $ Name = $ temp ["basename"]; // file name $ Dir = $ temp ["dirname"]; // folder where the file is located $ Extension = $ temp ["extension"]; // File extension $ Savepath = "{$ dir}/{$ name}"; // saved path of the thumbnail. The new file name is * .thumb.jpg.   // Obtain basic image information $ Info = getImageInfo ($ src ); $ Width = $ info [0]; // get the Image width $ Height = $ info [1]; // get the Image height $ Per1 = round ($ width/$ height, 2); // calculate the aspect ratio of the original image. $ Per2 = round ($ w/$ h, 2); // calculate the thumbnail aspect ratio.   // Calculate the scaling ratio If ($ per1> $ per2 | $ per1 = $ per2) { // If the aspect ratio of the source image is greater than or equal to the aspect ratio of the thumbnail, the width prevails. $ Per = $ w/$ width; } If ($ per1 <$ per2) { // If the aspect ratio of the source image is smaller than the aspect ratio of the thumbnail, the height prevails. $ Per = $ h/$ height; } $ Temp_w = intval ($ width * $ per); // calculates the width of the scaled source image. $ Temp_h = intval ($ height * $ per); // calculate the scaled height of the source image. $ Temp_img = imagecreatetruecolor ($ temp_w, $ temp_h); // create a canvas $ Im = create ($ src ); Imagecopyresampled ($ temp_img, $ im, 0, 0, 0, $ temp_w, $ temp_h, $ width, $ height ); If ($ per1> $ per2) { Imagejpeg ($ temp_img, $ savepath, 100 ); Imagedestroy ($ im ); Return addBg ($ savepath, $ w, $ h, "w "); // The width takes precedence and the background is added when the height is insufficient after scaling. } If ($ per1 = $ per2) { Imagejpeg ($ temp_img, $ savepath, 100 ); Imagedestroy ($ im ); Return $ savepath; // Proportional Scaling } If ($ per1 <$ per2) { Imagejpeg ($ temp_img, $ savepath, 100 ); Imagedestroy ($ im ); Return addBg ($ savepath, $ w, $ h, "h "); // The height takes precedence and the background is added when the width is insufficient after scaling. } } /** * Add background * @ Param string $ src image path * @ Param int $ w background image width * @ Param int $ h Background Image Height * @ Param String $ first determines the final position of the image. w width first h height first wh: proportional * @ Return returns the image with the background added. ***/ Function addBg ($ src, $ w, $ h, $ fisrt = "w ") { $ Bg = imagecreatetruecolor ($ w, $ h ); $ White = imagecolorallocate ($ bg, 255,255,255 ); Imagefill ($ bg, $ white); // fill the background   // Obtain the Target Image Information $ Info = getImageInfo ($ src ); $ Width = $ info [0]; // Target Image width $ Height = $ info [1]; // Target Image height $ Img = create ($ src ); If ($ fisrt = "wh ") { // Proportional Scaling Return $ src; } Else { If ($ fisrt = "w ") { $ X = 0; $ Y = ($ h-$ height)/2; // center vertically } If ($ fisrt = "h ") { $ X = ($ w-$ width)/2; // horizontally centered $ Y = 0; } Imagecopymerge ($ bg, $ img, $ x, $ y, 100, $ width, $ height ); Imagejpeg ($ bg, $ src, 100 ); Imagedestroy ($ bg ); Imagedestroy ($ img ); Return $ src; } } ?> Usage: $ Filename = (_ UPLOADPIC ($ _ FILES ["upload"], $ maxsize, $ updir, $ newname = 'date ')); $ Show_pic_scal = show_pic_scal (230,230, $ filename ); Resize ($ filename, $ show_pic_scal [0], $ show_pic_scal [1]);