Digital Workshop

Hi,

I don't hold out much hope, but is there a way to alter an image's contrast and brightness from within a publication?

I am creating an interactive exercise where people will view b&w x-ray images. Normally when viewing these we would alter contrast and brightness to visualise different aspects of the anatomy better, and wondered if there was any way at all to do it, either with up/down buttons or sliders etc?

As I said, I doubt it is possible, but thought I'd ask.

Many thanks

RB

There is at least one action to Fade in and out, or to Fade-to a specified level.
For starters, you can use a basic Mouse-over trigger, on a Mouse-click trigger.

You can search the forum to find one or more Slider controls you can use.
One way to "tie" a slider to your image control, is to have the slider set a variable -- let's say between 1 and 100 (or use 0 and 99). Then stack your "Fade to" action under that and have it fade-to the value of that variable.

Thanks Lar, I'd not thought of doing it that way, I'll give it a go.

RB

RB,

Sure.

Once you get it working basically, you can do a couple simple refinements to make it a better User experience.

Try either one of these, or both together.
1) add a Delay action after changing the variable (when slider is moved). The delay can be something like 0.05 seconds, or 0.01

2) is a little harder to explain.... so maybe someone else can jump in here to walk through it. And... there are several nice ways to approach this (create a Ticker/Loop, or else a "variable changed" trigger. And there are more ways.)

Let's say you create these actions with TWO triggers, and each having their own set of actions.
The first part is as above. Trigger is based upon the slider being dragged, and dropped. Then it sets some variable to the right value or range. (we can help you more with that).

The second part is to create a "variable changed" trigger... based on that same variable.
Under that trigger:
add an action for Delay 0.02 (or other time you like)
add an action to perform the Fade To of the object.

Intuitively, I would guess the delay under the slider should be 1/2 to 1/5th the delay under the detection of variable changed. But maybe that is backward?

Using Opus 8's new restrict to parent function, a simple slider is simple.

Here's a variation of Lar's Theme (sounds like something John Williams wrote ). The simulation of 'brightness' of the image is controlled by varying the amount of white light beneath the translucent x-ray image.

I don't think contrast would be possible without using a DLL.

Mack

P.S The slider can be used by anybody simply wanting to control any varying aspect such as rotation, object size, volume, etc.

I do apologise for the delay in replying to these suggestions, but they are brilliant. Mack, I can't thank you enough, that is really brilliant.

Thank you so much.

RB

Since this is a training application, you can prepare the imges before, so you have several images of different contrast and brightness, then map the slider positions to the image. It wouldn't have the resolution of an analogue system, but the user would understand the concept.

HI sandyn,

I had thought about this, and had a play with it, but to get one step either side of a nominal mid point, for both brightness and contrast, would require a total of nine versions each image. I got excessively confused trying to create those nine accurately, even going so far as to try and create a Photoshop action to do it automatically. It did get the general idea, but ultimately wasn't close enough to what the delegates will be used to, and so didn't feel as if it was worth the time that would need to be put into it.

Two steps each side of a mid point would have been closer, but probably too much for my brain to cope with

RB