SwiftUI ObservedObject causes undesirable visible view updates

Question

I am working on an app that applies a filter to an image. The filter has a number of parameters that the user can modify. I have created an ObservableObject that contain said parameters. Whenever one of the parameters changes, there is a visible update for views, even if the view displays the same value as before. This does not happen when I model the parameters as individual @State variables.

If this is to be expected (after all the observed object does change, so each view depending on it will update), is an ObservedObject the right tool for the job? On the other hand it seems to be very inconvenient to model the parameters as individual @State/@Binding variables, especially if a large number of parameters (e.g. 10+) need to be passed to multiple subviews!

Hence my question:

Am I using ObservedObject correctly here? Are the visible updates unintended, but acceptable, or is there a better solution to handle this in swiftUI?

Example using @ObservedObject:

import SwiftUI

class Parameters: ObservableObject {
    @Published var pill: String = "red"
    @Published var hand: String = "left"
}

struct ContentView: View {

    @ObservedObject var parameters = Parameters()

    var body: some View {
        VStack {

            // Using the other Picker causes a visual effect here...
            Picker(selection: self.$parameters.pill, label: Text("Which pill?")) {

                Text("red").tag("red")
                Text("blue").tag("blue")

            }.pickerStyle(SegmentedPickerStyle())

            // Using the other Picker causes a visual effect here...
            Picker(selection: self.$parameters.hand, label: Text("Which hand?")) {

                Text("left").tag("left")
                Text("right").tag("right")

            }.pickerStyle(SegmentedPickerStyle())
        }
    }
}

Example using @State variables:

import SwiftUI

struct ContentView: View {

    @State var pill: String = "red"
    @State var hand: String = "left"

    var body: some View {
        VStack {

            Picker(selection: self.$pill, label: Text("Which pill?")) {

                Text("red").tag("red")
                Text("blue").tag("blue")

            }.pickerStyle(SegmentedPickerStyle())

            Picker(selection: self.$hand, label: Text("Which hand?")) {

                Text("left").tag("left")
                Text("right").tag("right")

            }.pickerStyle(SegmentedPickerStyle())
        }
    }
}

Answer 1

Fast forward to 2023. The original example with ObservedObject no longer causes undesired visible updates, which seems to indicate that this was indeed a minor 'bug' in SwiftUI. Note that you need to use @StateObject instead of @ObservedObject in case ContentView instantiates parameters. Otherwise, you should pass Parameters to ContentView.