Sunday, February 21, 2010

Artificial HDR

If only cameras were capable of capturing exactly what our eyes see it would be much easier. However the cameras are not quite at the level of human eyes yet in terms of adjusting to light.

The good news is that HDR (see a longer explanation here) can be used to increase the dynamic range in a photo to capture more details that otherwise would be hard to include in the photo.
Granted this can all be overused but as with anything else... in moderation it's awesome :-)

Doing HDR the "correct" way is of course capturing photos with different exposures to draw out details in the various areas of the photo.
However what if you got one photo and at the time didn't get a set of photos?

Here I will show you how you can use 1 photo (captured in camera raw format) to generate a HDR photo using Adobe Lightroom and Photo matrix (other tools can be used too).

Starting out with this photo (which I btw. shot out the window of the car).


In Adobe Lightroom select the photo and create two virtual copies of the photo. You can do this by right clicking the photo and selecting "Create Virtual Copy" or selecting the same from the Photo menu (ohh yeah do this twice to create two virtual copies).



Select the first virtual copy and decrease the exposure 1 stop (the double left arrows)



Select the second virtual copy and increase the exposure 1 stop (the double right arrows)



Now you have three photos where one has an exposure as captured by the camera. One is underexposed by one stop and one is overexposed by one stop.



Now you can export the photos to finish the HDR in photo matrix or select the photos and select to create HDR with Adobe Photoshop (found in the edit menu).

I have here exported the photos and selected them for processing in Photomatrix (click generate HDR and select the files).



Once the files have been selected you may have to set the exposure differences manually.



Since the photos are all based on one capture there are no need to align the photos or attempting to reduce ghosting (nothing has moved in the photo between "captures").



Now the image displayed may not look "right" since it has not yet been processed. By hovering over the image you can see a preview of the expected result though.
This step I just skip right to the part of clicking "Tone Mapping" which is where step 1 of the magic is going on.



After Tone Mapping there is a pretty good preview of what to expect. Generally Photomatrix is doing the automatic settings pretty good so I don't even try to fine tune unless there is something that "sticks out".
Continue to part 2 of the magic and click Process.



All there is left to do now is save the photo and here is my final result which is created with a single photo (captured with camera raw).
Granted this is not the "correct" way to do it and creating it with a real capture where individual photos has been captured with different exposures will reveal/capture details that may have been lost in a single capture (darkest/lightest areas missing details).
However for a polishing of a single photo I think this is pretty decent :-)





Monday, February 15, 2010

Ink and watercolor

In this tutorial I will go through the steps to transform a photo to a ink and watercolor image.
This will be with ink outlines and watercolor like colors.

For the walkthrough I selected the photo below from a medieval re-enactment we visited in Denmark during the summer time.

Start out by creating a copy of the background/image layer. Either using the "Duplicate Layer..." function from the "Layer" menu or the keyboard shortcut CTRL+J.

Select the new layer and desaturate it (Image->Adjustments->Desaturate).

This layer is to be the outline/ink layer. This could be done by tracing all the edges in the photo which will create a great result. However it will also take a long time depending on how detailed the photo is. Here is a faster way that will create good results with little effort.
From the Filter->sketch menu select "Photocopy..."

In the settings for the photocopy filter select amounts that creates outlines for your image (this may vary depending on the resolution of the photo). In most cases selecting these values will work. Detail: 4, Darkness:12.

Having applied the filter only the outlines should be visible in the photo.

Before removing the unwanted white "filling" in the layer. Add a white layer to the layer stack (this could be black as well or you could switch between the black and white).
Start by selecting the bottom layer in the layers panel and add a new layer (using the button at the bottom of the layers panel or New->Layer from the Layer menu).

White the foreground/background colors set to default (shortcut key d). Select the new layer and fill it with the background color (white).

Now select the outline layer (top layer) in the layer stack.

To delete the white background in between the outlines. Select the magic wand and make sure the "Contiguous" is off (not checked).

Click in between the outlines to make the selection. This will display the "marching ants" indicating the selected areas.

Delete the content of the selected area (using the delete key) and notice how the background in the layer changed to indicate the now transparent areas.

After deleting the background in the outline layer remove the selection Select->Deselect (or CTRL+D).
To trim the outlines and make sure all the white background is all gone. Ensure the outline layer is still selected and trim the white using Layer->Matting->Remove white matte...

To start coloring the image, select the photo layer at the bottom of the layer stack.

Duplicate the layer Layer->Duplicate Layer... (or the shortcut CTRL+J).

Hide the white fill layer by clicking the eye next to the layer.

To simplify the colors in the image, select the new painting layer (if it's not already selected) and apply a surface blur filter. Filter->Blur->Surface Blur... Settings for this may change depending on the resolution of your photo but starting out with a setting of Radius: 20 pixels andThreshold: 20 levels should do the trick in most cases

Move the painting layer up in the layer stack by simply clicking and while holding the mouse button down, drag the layer up.

Add a layer mask to the painting layer using the "Add Layer Mask..." button at the bottom of the layer stack or the menu Layer-> Layer Mask->Hide all.

If the mask didn't get created using the Hide all function it will be empty (showing all). Set it to hide all by selecting the layer mask and fill it with black.

To fill in the color with a textured watercolor look. Select the brush tool and load the wet media brushes by clicking the drop-down arrow next to the brush shape in the brush options as shown below.

After loading the set of brushes select a watercolor brush (or experiment with others). In this example I selected the watercolor brush with a textured surface. To better control the application of the color it is a good idea to lower the opacity and flow of the brush.

With the mask selected in the painting layer start painting white in the areas you want color to appear. This is an area where experimentation can change a lot. Try to use different size brushes, brush lengths. Just start brushing away. If everything goes wrong it can be undone by painting with black in the layer mask or undo everything by filling the layer mask with black.

After a good bit of brushing here is what my layer mask look like in the layer stack.

If the outlines doesn't stand out as much as you would want them to the effect can be increased by selecting the outline layer and copying the layer (see previous).

Select the new layer and change the layers blend mode to Multiply


Here is the result of the painting compared to the original photo.

Original


Ink and watercolor