Me and my wife had a quick winter holiday visit in Suomenlinna. On these pictures I simply used Elsamuko's 'National geography' filter: https://sites.google.com/site/elsamuko/gimp
In this tutorial I used two different images. On first one there is just a single tree against snow, and two trees on another. First I just open both using 'File > Open as layers...' on GIMP (hold Ctrl key down when selecting multiple images). Then I changed the layer mode to 'Darken only' for the upper layer (image with two trees).
Now comes the tricky part. Follow the instructions on my previous tutorial but instead of using 'Radial gradient', keep the default 'Linear gradient' to select half of the image. When done you should get dotted selection line that vertically split the image from the middle. Now you can use 'Select > Invert' to toggle between left and right side of the image.
In this example I first used left side selection for image with two trees to blur left side of it 10 pixels 'Filters > Blur > Gaussian blur...'. Then I used 'Colors > Curves' to brighten the left side of the image a little.
Next I changed the selection for right side of the two trees image. For that side of the image I gave heavier Gaussian blur (20 pixels), and made it even lighter with Curves. As a result I got image with three trees where one of them looks sharp on the front middle of the image, another tree slightly blurred on left, and more heavily blurred tree on the right. A clever way to create shallow depth of field look on the image, I think. And also a clever way to adjust brightness only for selected part of the image.
Today I discovered 'quickmask'. On bottom left corner of the picture area on GIMP there is so called 'quickmask' button. To use it first make sure you select all: 'Select > All'. Then just click that quickmask button. Now the picture should turn into reddish mask.|
EDIT: For some reason the image does not always turn reddish when mask becomes applied. Do not let that bother but just continue to next stage.
|Next stage is to decide what you select, and for this you can use 'Blend tool' with different 'Gradients'. In this example I picked 'Radial Gradient' because I want to treat the edges differently than the center of the image. When you are done you get the reddish mask blending gradually from darker red to lighter.|
|Now all you need is to click the quickmask button again, and the mask turns into selection. Now make sure you get selected what you wanted. If just the border of circle flickers, then circle it is what you get. But if you choose 'Select > Invert', then it is the area between the circle and edges of the image.|
|Finally you can for example duplicate the layer, run 'Filters > Artistic > Photocopy...' for the edge part of the image, and then turn the overlapping layer to 'Soft light' layer mode. As a result you get nice white vignetting (edges are lighter than center of the image).|
|Here it comes, as I somewhere promised, a stage by stage instructions how to merge images creatively. First of all you need at least two images to work with. Here's the first one I used for this example.|
|And here's the other one. As you can see, this is somewhat similar with the first shot, but the tree is different. You can also shoot the same subject and try to change something else like angle of shoot, zoom, or use different light. At twilight you can for example shoot one shot with flash and another without it.|
|What you then do on image editor (GIMP or PhotoShop) is that you open the two (or more) images on separate layers. Next you need to try and decide what layer mode you use for topmost layer(s). Try for example 'Soft light', 'Hard light' and 'Darken' layer modes. Which one is the best depends much on subject and outcome you want to achieve. Here I wanted to multiply the branches against snow, thus selecting 'Darken' layer mode.|
|Next stage is the "blurring stage". The idea is to blur one of the layers either just a little or quite much, depending again on what you want to achieve. With 'Gaussian blur' 50 for 1000 pixel wide images you get just tones enhanced, which can be cool when pictures are differently lit. Here I wanted to achieve something similar as on so called "tilt and shift" images, thus giving only 'Gaussian blur' 10 for the image with a house on background.|
|Quite often one may wish to enhance the image using so called "contrast mask". What you do then is that you first merge the image onto one layer, then duplicate, change the duplicate into 'Soft light', invert the duplicate, turn the duplicate to balck and white, and finally blur the duplicate with Gaussian blur (e.g. 50). Now you get image that may look flat (little contrasts) but you also get more tones on shadows and highlights.|
|The final stage is where you do your usual magic. Just remember to merge the image onto one layer once again. You may just try to increase contrast and lightness. Here I first ran Elsamuko's LOMO script, and after that I increased the lightness for middle tones with 'Curves tool'. Not quite finished yet though, but hopefully you got the idea. Click here to see the final image in full size.|