Add Texture to Your Photos

Here is another little trick to make you photos more interesting. How to add texture to certain parts of a photograph, using the GIMP. This short tutorial is not supposed to demonstrate any particular interesting picture, although one might think the result is kinda artsy.

Well, lets see what we got. A slightly overdone HDR shot of a beach, with some strange coloring going on in the sky. The sky indicates that during post-processing, the program ran out of color space.
Have a look:

Beach HDR, out of color space!

This shot is hard to fix. Re-doing the post-processing seems the only option. But, what if you don't have the RAW-files?

Let's try to get some artistic element to the rescue... adding texture!
This will be the texture to add, a photograph of a wall:

Pretty boring white wall...

So, I decided to take a photo of a brick wall which has been painted white, great.

Lets quickly compare the 2 images. The image of the beach in relatively dark in the lower left corner, while the image of the wall is brightest in the same region. Or, in other words, the upper right of the brick wall's image is darker than the lower left. In a way, those images are complementary.
Actually, I am not making use of this, but this will be explained later.

In the GIMP, I opened the image of the beach, as you would do normally anyways. Than, I used "Open as Layers..." to load the image of the wall.
Now, the only thing you will be able to see is the image of the wall, since this is now the first layer. By default options this layer is in mode "Normal" with an opacity of 100%.

Click on the layer that represents the wall. This should cause a white frame around the layer's icon. Now select the mode to the option "Multiply".
The intermediate result will look like this:

Like projecting a slide on a white wall...

If you are after an effect like projecting a slide on a wall, this is what you may want to do!
Note that the left and right lower corners of the image have a similar brightness; this is due to the opposing gradients of the original frames.

Let's give a further "creative" touch and change the effect of the wall.
With a layer mask, on the wall, one can add a gradient, which will fade out (or in) the contribution of the textured frame.
In this example, I use a black gradient from below. Having the following effect on the texture frame:

wall w/ gradient

After having applied the gradient to the texture frame, the left-right difference on the lower third is gone, and so is the nice compensating effect...

This results in a slightly different final image:

final result

Mind you, this is not supposed to be fine art. This technique of adding texture, as you might see, is clearly able to distract from the deficiencies, i.e. lack of color space, of the original photo.

Lunar Photography on the Cheap II (gratis/free)

Yesterday I showed how to take a lunar shot with a simple point&shoot camera with a 8x zoom lens. Of course, the trick was that this inexpensive camera is able to shoot in RAW (thanks to CHDK).

Towards the end of the post, I mentioned that I used commercial software, i.e. Photomatix, to deal with the "develop" part of things. Further I stated that this process would potentially be possible with "free" software.

Today, I gave it a try with Luminance HDR (version 2.3.1), which is free software, to my knowledge.


Preparation

Luminance HDR asks for bracketed frames. Well, with my single shot, I only got one frame. So I used a very common HDR trick, namely creating more frames, differently "exposed" by software. Mind you, I am shooting DNG (digital negative).
Here is how this trick is done (with is free software by know):

• open the shot in Rawtherapee
• go to the EXPOSURE menu
• click on 'Neutral' (this should bring everything to default values)
• export the image using TIFF-16bit (this is your 0Ev shot)
• drop the exposure to -2Ev
• export the image using TIFF-16bit (this is obviously your -2Ev shot)
• raise the exposure to +2Ev
• export the image using TIFF-16bit (this is obviously your +2Ev shot)

Done! You now got 3 frames of identical size and format with different exposure values. That's what HDR-software likes!

The first results in Luminance HDR were not that great. Actually, they were so bad (a lot of grain and noise, over-exposed bits and what not), that I decided not to show those. The software is not easy to use, so I will give it a second try (see below).


Gratis

There is another bit of HDR-software available "for free", i.e. gratis. So we are not dealing with free software here, however, one can use this program without paying for a license.
The program is called FDRTools Basic.

Having loaded the 3 frames into FDRTools, the results were better, but not really satisfying yet. It appeared that the +2Ev frame was not serving any reasonable purpose, hence, I excluded this frame from the process (this is a very nice feature of FDRTools, it is like making invisible a layer in GIMP).
And guess what, the result was instantaneously much better than yesterday's Photomatix results!
Here is the re-sized output, converted into PNG:

2 frames pseudo HDR using FDRTools Basic

To me, that was a stunning result, coming from gratis software! A lot less noise than in yesterday's attempt.

Still, this photo could be slightly improved in GIMP, using the masking technique I explained in the previous post, i.e. the sky was treated with 'wavelet denoise' and the moon with 'wavelet sharpen'.

after GIMP

In the original 16 Megapixels image, the difference is somewhat visible. The above shown scaled down versions look almost identical to me.


Free

And here is the promised text about the entirely free solution.
Learned from my experience with FDRTools, I only loaded the -2Ev and the 0Ev frame into Luminance HDR. So for so good, but now the hard part.
Luminance HDR offers a lot of different algorithms to combine the frames. I went for "Profile 1".
Luminance HDR offers even more algorithms to tone-map the image. And this is where it went wrong in the earlier attempts. Having tried all different options, I selected "Reinhard '02", pulled 'Key Value' to 0.01 (none of the other tone-mapping parameters have any effect at this stage). In order to darken the image, I use the 'Adjust Levels' histograms. And voilà, we got a presentable result created by free software.

2 frames pseudo HDR using Luminance HDR

There is still more noise in the image than in the image created by FDRTools. Again, this calls for the GIMP.
Here we go, same technique as described previously... and here is the result:

denoise / sharpen by the GIMP

Yep, the differences are getting really subtle now, which of course speaks for the use of free software!

I hope you enjoyed this little journey from commercial to gratis to free. Personally, I am not sure if gratis or free won the contest. But certainly commercial produced the least favorable result in this particular case. But than, using software of this nature is somewhat of an unfair abuse, isn't it?

GIMP Your Photos!

To me, photography has got several steps. Those steps, I learned in the beginning of the 1980s, when I was learning B&W-photography the classical way.

• taking the shot by
  - measuring your lighting
  - deciding of aperture and shutter speed
  - framing the picture
• developing the film, according to the "exposure compensation" (A.A.'s Zone System)
• enlarging the print by
  - taking exposure test strips
  - thinking of effects and cutting out masks from paper
  - exposing the print and potentially using said paper masks
  - developing & fixing
  - drying the prints

Yes, that was a lot of work to get a photo at that time!

Today we have computers and software like Adobe Photoshop. And there is also GIMP is a pretty powerful replacement for Photoshop. The advantage of GIMP is, not only is it entirely free, it is also available for all popular platforms. I have to admit, it is not the easiest program to use and the user manual is pretty massive.

Occasionally, I learn a trick, e.g. when people demonstrate the use of Photoshop, which can be transferred to GIMP.

Here is one, it is pretty simple and allows for some artistic improvement of photos, I hope that blogger does not "improve" the images too much (although it ugly-fied the plain image pretty good).

plain shot

after the little trick

Here is the workflow:

1. duplicate the layer (drag&drop layer icon to the duplicate icon)
2. set the layer mode to "multiply" (pull down menu on top)
3. add a layer mask to the top layer (right-click on the top layer icon)
   => select "white"
4. activate the layer mask (by clicking on the white icon)
5. select the airbrush tool with a soft brush and adjust the size
6. be sure the color selected is black (!)
7. selectively paint your talent with the airbrush 

In the above example, blogger helped me to make the unmodified photo look even more terrible and flat as is originally.

I decided to add more depth to the statute by bringing the forehead and the close shoulder more to the attention of the viewer by lighten it. This is done by removing the influence of the top layer by masking parts out.

You will see, this little trick will help you to make dull photos a lot more interesting.

BTW, in the good old wet darkroom times, I would have done more or less the same! I would have screened portions of an image, which I wanted brighter, with a little mask, so that said portions would be less exposed (the test-strips are your friends!), creating the effect I was after.