Function read

Create a reader which can be used to load an exr image. Allows you to exactly specify how to load the image, for example:

use exr::prelude::*;

// the type of the this image depends on the chosen options
let image = read()
    .no_deep_data() // (currently required)
    .largest_resolution_level() // or `all_resolution_levels()`
    .all_channels() // or `rgba_channels(constructor, setter)`
    .all_layers() // or `first_valid_layer()`
    .all_attributes() // (currently required)
    .on_progress(|progress| println!("progress: {:.1}", progress * 100.0)) // optional
    .from_file("image.exr")
    .unwrap(); // or `from_buffered(my_byte_slice)`

You can alternatively use one of the following simpler functions:

1. read_first_flat_layer_from_file
2. read_all_rgba_layers_from_file
3. read_all_flat_layers_from_file
4. read_all_data_from_file