You change the amount of pixels for both the width and height to resize a JPEG file image. Add pixels to increase the size, or decrease pixels to reduce size. Resize images in JPEG format by using a photo resizing tool or site, such as PicResize.com, as of 2015.
Select a photo to resize. Choose to customize your photos by entering the pixel height and width that you require. PicResize.com allows you to resize photos of the BMP, GIF and PNG formats, in addition to the JPEG format. Furthermore, photo editing tools allow you to crop, flip and rotate images to your desired specifications.