A couple of supplementary notes to the many words of wisdom from @inq and Ron @zander.

I haven't checked my thoughts and facts, so please take these notes as suggestions to find out more, rather than hard facts from me, but:

I suspect a lot of the basic video processing, such is image resizing, is done in the camera chip itself, possibly to fixed sizes, etc. that match various industry norms. These may be very useful if they match your requirements, but you may find it hard or impossible to meet your requirements if the chip does not support your needs.

Plus, check the amount of RAM in the ESP32 is enough for any processing you intend to do on it. Depending on the frame size you select, and the algorithms you wish to run, you might not have enough to hold even a single frame, which could preclude some operations.

Of course, as the web server and other examples show, it is possible to do a lot of things with the ESP32 CAM, but to minimise the risk of disappointment, it is worth checking that the hardware has the basic capabiities to meet your aspirations.

Best wishes, Dave

And there are other tutorials that will let you control the ESP32-CAM.  The CAM interface is extremely detailed and seems like there were a lot of API's you'd have to master.  If you Google very specific aspects like "Arduino ESP32-CAM zoom settings" you might come up with very pointed code that you can study, learn and incorporate into a bigger program.  

I imagine as you get into it and start showing some skin in the game and show specific pieces of code that you are having trouble, we can help you in understanding or even debugging.  

Besides, I'd still recommend you just add the pertinent pieces (zoom, ASA settings) to the existing UNO/C++ server code and to the HTML/JavaScript user interface code and use it with phone, tablet, Windows, Mac without having to learn Android or iOS.

My main objectives to create an application is to control the camera parameters such as ISO, Exposure time and the digital zoom of the image (say 2x,3x,5x,10x, etc.). I want to control these parameters using the camera app

@biprav Can you elaborate on the following? How many years of software development do you have and in what languages are you qualified? Then we will have a better idea how to help.

The main problem is that I don't have any such programming knowledge.

Let me understand this...  You have the complete web solution working, but it is not going to be satisfactory for your needs.  So you want to learn the Arduino INO and C++ so you can create your own server that will work directly with an Android app say... via Bluetooth.  AND then you want to learn all that is necessary to creating that native Android application, but you have never written any code?

If this is correct... then I would suggest start with Google and look for Arduino programming tutorials, then C++ tutorials and then Android programming tutorials.  You will find that the code in that web version is huge and extremely advanced.  I must be misunderstanding you or you are totally underestimating how monumental that task is for even a decade senior programmer.

Besides... I think you will be disappointed in the results if magnification is what you are after.  OV5640/OV2640

The best resolution of those two are 2592x1944.  Neither of them have an optical zoom.  Therefore at 10x you will only have an effective resolution (of the entire image) of 259 x 194.  Is this acceptable resolution for your project?

My main objectives to create an application is to control the camera parameters such as ISO, Exposure time and the digital zoom of the image (say 2x,3x,5x,10x, etc.). I want to control these parameters using the camera app

Most if not all that is already done. I would not advise digital zoom, the tiny sensor is already quite poor for any meaningful image capture.

My main objectives to create an application is to control the camera parameters such as ISO, Exposure time and the digital zoom of the image (say 2x,3x,5x,10x, etc.). I want to control these parameters using the camera app