You can apply most image editing commands to a single paint object if it’s selected or in Edit mode.You can also apply most commands to multiple selected paint objects. You can set image modes, apply filters, and adjust settings for multiple paint objects at the same time.
In most cases, a command affects an active selection, or an entire image if nothing is selected in Edit mode.
When you apply an image-editing command to more than one selected paint object, you can’t use the Preview option if the dialog box has it. Preview is available when a single image is in Edit mode.
You can apply a command by choosing Image | Adjust or by using the Adjust menu located in the Properties bar.
The following summarizes how image-editing commands can be applied.
Some dialog boxes for image-editing commands include histograms and preview options to help you achieve the effect you want.
Most dialog boxes for image-adjustment commands include a Preview checkbox. Select the Preview option to see how settings affect the image. Preview is available only when a single paint object is in Edit mode.
A histogram plots the relative number of pixels in each brightness level in an image.
In the above, shorter bars on the left indicate that the image doesn’t contain large areas of very dark pixels. Higher bars toward the right of the graph show that the image contains large areas of medium and very bright pixels.
With an image selected or in Edit mode, choose Image | Histogram.