Move: Adjust the view through panning (drag) and zooming (mouse wheel)
Transform: Move a selection along a color axis in a color view, resulting in a color shift. Use the handles to resize the selection, resulting in the stretching of the histogram.
Rectangle/Lasso/Brush Selection: Select pixels in any of the views. Hold the 'Shift' key to add pixels to the current selection, the 'Alt' key to substract, and 'Shit + Alt' for a union selection.
Paint Brush: Paint pixels in any of the views
Color palette: Open the color palette

Change the view: Rearrange the pixels as the image, as a image histogram or as a color scatterplot. Possible views are image (Image), histomagram view: lightness (Light), red channel (R), green channel (G), blue channel (B), hue (Hue), saturation (Sat), and a lightness/hue scatterplot view (Color)
New view: Duplicate the current view in a new window

Load images: Beside the traditional File > Open menu command, the 'Examples' window provides a quick access to image collections. From this panel, it is possible to add a single image or a directory of images through the buttons at the bottom. Clicking on an image in the list loads the new image, causing all the changes in the current image to be lost.

Precomputing color conversion: Color conversions are costly and can affect histomages performances. At the loading of the first image, histomages automatically starts the pre-computation of color lookup tables to improve performances when manipulating pixels in color spaces other than the R, G, B channels. This caching pre-computation can take time and requires memory resources. This process can be cancelled through the dialog window, Histomages will still work.