image-resolution

问题 I try to change the size and the resolution of an image programmatically, afterwards I save this image. The imagesize in the imageView is changing, but when I look at my file "file3.png" it always has the original resolution of 640x1142. I googled around but can't find a solution. I try to redraw the image. But maybe it's the wrong strategy. thanks @IBAction func pickOneImageBtn(sender: AnyObject) { //load image from path pickedImage.image = loadImageFromPath(fileInDocumentsDirectory(

问题 I try to change the size and the resolution of an image programmatically, afterwards I save this image. The imagesize in the imageView is changing, but when I look at my file "file3.png" it always has the original resolution of 640x1142. I googled around but can't find a solution. I try to redraw the image. But maybe it's the wrong strategy. thanks @IBAction func pickOneImageBtn(sender: AnyObject) { //load image from path pickedImage.image = loadImageFromPath(fileInDocumentsDirectory(

问题 I want to Retrieve Image Resolution(DPI) of an image (JPEG,PNG,SVG,GIF) without using any PHP extension (like imageMagick). I searched everywhere, but I couldn't find a perfect solution. I tried below code (got from link) function get_dpi($filename){ $a = fopen($filename,'r'); $string = fread($a,20); fclose($a); $data = bin2hex(substr($string,14,4)); $x = substr($data,0,4); $y = substr($data,0,4); return array(hexdec($x),hexdec($y)); } But I am not getting the correct Horizontal and vertical