Simple web based program that can remove background to make it transparent image for various formats

We are seeking an experienced Image app developer who can build a web based image converter that can do the following: 1 ) Remove background on an image in a variety of common formats 2) Stretch images and videos i.e re-save in different pixelations 3) Save in correct format and interpopulate (where needed) videos caputed e.g in 720p to 1080p Full HD and stretch image for horizontal or vertical playback 4) ability to save video or file in specific Format/Resolution: Video e.g video format is in .mp4 file, Max File size 20 MB, landscape, Width*Height (1280*720) Image e.g. image format is in .png file, Max File size 2 MB, Portrait, Width*Height (720*1080)