A) Simple introduction

You can make, by using this frame of compositing between two images (or two sets of images). Compositing is the possibility to superimpose two images and thus create a single one; one single image (which is used as a bottom view → somehow a background and which do not includes an alpha canal [transparency]) and another image (which can be used as a foreground, and which usually includes [and in this case] an alpha canal). In EKD you have the possibility to work on a set of images creating the background (in case of mouvement) or on one single image (in case of a fixed background → fixed camera).

Compositing can be really useful if, for instance, you wish to remove a character in action previously shoot on a plain blue background (and set into EKD by Image > Alpha mask/3D) out of his context (decontextualising) and copy it on some other images (have a look at the case described soon after).

B) Loading images with alpha canal

Go to the Image(s) with alpha canal tab and click on the button Add.

A dialogue box appears, unfold then the directory and choose the one in which you have your images (on the left side), your images are shown as thumbnails (by default) on the right side. To select several images, click on the first thumbnail, then, by keeping the SHIFT key pushed, click on the last thumbnail, then click on Add. In this dialogue box the selected images have to be in the foreground.

For information ; in the Image(s) with alpha canal tab, you can only open PNG or GIF images, you can check it out by clicking on the Filtres button (images with .png and/or .gif extensions includes an alpha canal, which means transparency … and they are in RGBA mode).

Here are the images (represented by the thumbnails) onced you’re in the main window (in the Image(s) <ith alpha canal tab).

C) Loading images without alpha canal

Go now in the Image(s) without alpha canal tab and click on the Add button.

A dialogue box appears, unfold then the directory and choose the one in which you have your images (on the left side), your images are shown as thumbnails (by default) on the right side. In our exemple we opened one image only, you just have to select it and then click on Add. In this dialogue box the selected images have to be in the foreground.(here we choose just one image for the background).

Here’s the image (represented by its thumbnail) once in the main window (in the Image(s) without alpha canal tab).

D) Intermediate display

We’re now going to display the background image so that you will be able to compare this image with one of those that we’re going to obtain at the final step of the compositing, select the thumbnail and click on Add.

Once you’ve done it, the image is shown on a new window (click on Return to go back to the main window.

E) Settings

Go now to the Settings tab and leave the settings by default. If you wish to know what these settings are about, follow this link).

F) See the result

You can see the result in image in a new window (and before the final treatment) by the See the result button.

If your images are not at the same size, a dialogue box asks you if you wish to resize your images (it’s better to answer Yes, otherwise, the treatment is not going to work).

Here’s the result in the display window (this is the compositing between the last image among all in the Image(s) without alpha canal tab and the first image among all in the Image(s) without alpha canal), click on the button Return to go back to the main window.

G) Final treatment

It’s time now to deal about the final treatment, to do this click on the Apply ans save button.

If your images are not at the same size, the previously dialogue box asks you if you want to resize your images (it’s better to say Yes, otherwise, the treatement is not going to work). The saving window (Save) gets open, in this one, on the left side, select the directory of destination (if you need it, unfold the directories), write the title in the text frame File name : and click on the button Save.

During the treatement, the progress bar is in action.

H) Final display

At the end of the treatment your images are displayed in the Image(s) after treatment tab.

In this tab, you can see the images (the result of the compositing) by selecting the thumbnails, you can also start the slide show, display the images at their real size, zoom in …, if you wish to know more, you are requested to check details here (the last image of the tutorial).

I) Informations about the paths

To end it up go to the Infos tab, to see the path of the images before and after the treatment.

J) Result by the image

Here’s one of the images coming from the compositing (images overwrite).