A portable network graphics (PNG) file is an image format file that uses data compression in a lossless form and is the preferred image format for Apple iPhone. When you take a screen capture on your iPhone, it will be automatically saved to the camera roll as a PNG file, and you can view it directly on the iPhone screen without installing any third-party iPhone apps. To load a PNG file, you must first save it to the iPhone’s camera roll.
Press the home screen and power button at the same time to create a PNG screen capture.
Save PNG file to camera roll
Press and hold the PNG image file displayed in the email or web page. A dialog box will appear, asking you to further explain what you want to do with the picture.
Tap the “Save Picture” button. The PNG record will be duplicated to the iPhone’s Camera Roll
If the email or web page contains multiple PNG files, click the “Save All Pictures” button. All PNG files in this location will be copied to the iPhone’s camera roll immediately, so you don’t need to save each file separately.
View PNG files on iPhone
Launch the photo application on the iPhone by tapping the icon on the home screen.
Click the “Camera Roll” folder in the “Album” section to display thumbnails of all the images and videos stored in the iPhone’s Camera Roll.
Click the thumbnail of the PNG file you just saved to display the image on full screen.
Swipe left and right to move between the pictures put away in the camera roll
Tap anywhere on the screen to display the controls of the photo application, and then press the “Camera Roll” button in the upper left corner to return to the album overview.