After doing research and gathering a lot of information with images for many years, you face a huge number of file sizes. You may want to access your information through your iPhone or iPad apps. because of the file sizes, apps can't open them easily, can't sync them fast. And this problem will be solved by reducing the size of images.
The applications I gather my information on are:
Scrivener and TextEdit
I need to change file formats such as tiff and png to jpg and reduce the dimensions of images for example 800x800.
There are good applications such as ImageOptim and Resize to reduce the size of images, but I can't change the format of images inside "Package Content" of a file.
Sorry if you see mistakes. English is my second language.
If something is not clear, please let me know I will explain that.