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Vignettes are great, yes they can be regarded as a lens defect, but sometimes they can add that certain something to an image. I have seen other tutorials on the web which are very similar to this one, differing only in that I like to use  Layer Modes for most of my vignettes. I particularly like the boost to contrast and saturation that the Multiply mode gives, I think it has a more retro feel. Anyway let’s begin.

 
Step 1. Open your image in GIMP, right click on the “Background” layer and select Duplicate Layer. Note that this new layer has become the active layer, as denoted by the white border.

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Step 2. Right click on the new layer “Background copy” and select Edit Layer Attributes, enter the new name “Vignette” and select OK.

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Step 3. Right click on the “Vignette” layer and select Add Layer Mask…

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Step 4. In the Layer Mask dialog box choose the default White (full opacity) and select Add.

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Step 5. Select the Blend tool from the Toolbox, or by selecting Tools > Paint Tools > Blend. Ensure that your Foreground color is Black and your Background color is White. Use the default FG to BG (RGB) Gradient and change the Shape: to Radial.

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Step 6. Turn OFF the visibility on the “Background” layer by clicking on the little eye icon. Then Click in the center of your image (or the main point of interest) and drag out toward the corner of your image. Sometimes you may need to go out beyond the edges of your photo as I did in this example. Repeat this step as many times as is necessary, the aim here was to make the majority of Mischa’s face transparent.

This is a great example of Layer Masks in action. White areas are treated as Opaque (solid) while Black areas of the mask are treated as Transparent. The information is still there in the layer but the mask controls what is displayed.

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Step 7. The Blend tool produces a very soft transition between black and white, we can sharpen the vignette by shortening this transition. Launch the Curves tool by selecting Colors > Curves… Click to add a control point in the center of the graph and then raise the right hand portion and lower the left hand portion. You may need to experiment a little here to see what works.

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Step 8. Turn ON the visibility of the “Background” layer by clicking the little eye icon and change the Layer Mode: to Multiply

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That’s it. one nice subtle vignette effect. I recommend that you experiment with some of the other Modes, Overlay can work well, Burn can give massive saturation boost and Subtract can give a very dark vignette. Also experiment with the opacity to lessen the effect.

If you are still not quite getting the vignette you want try changing the Mode back to Normal and use the Brightness/Contrast, Levels or Curves tools to manually darken the “Vignette” layer. If you are trying this make sure that you select the “Vignette” layer (as in the actual image) rather than the Layer Mask, the white border will tell you which is active.

Happy GIMPin’

T.

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Haven’t posted in ages, too many irons in the fire me thinks. I am going to show a very simple method of enhancing the existing colours in a digital photo using GIMP. This tutorial is aimed at those who are new to GIMP and new to photo editing. This is based on GIMP version 2.6.4 and requires no additional scripts or plug-ins beyond the basic default installation.

Here’s a picture I took while out walking the dog one day, some rather sorry looking birch trees. My aim is to enhance the Yellows to give a nice autumnal feel and also to give a boost to the Greens, so let’s begin.

1. Open your image and from the Colors dropdown menu select Colors > Hue-Saturation…

2. Select the Yellow radio button and move the Saturation slider to the right to increase the stauration, in this example I have increased the saturation of the yellows by 20 as I felt that it suited this image.

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3. Select the Green radio button and again move the saturation slider to the right, this time I have increased the saturation by 30. When you are happy with the results click OK.

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Well that was easy, I rarely use the Hue and Lightness sliders so I am not going to take the time to explain what they do, but feel free to experiment with them or check the GIMP Help, if you haven’t installed the Help system they are all available on http://www.gimp.org

The Hue-Saturation tool really is quite useful, some possible ways you might use this tool of your own photos include enhancing blue skies, enhancing reds and yellows in sunsets, reducing red in faces (particularly sunburnt one’s). This list of possible uses is really only limited by you imagination. Here’s an example in which I have used the Hue-Saturation tool to desaturate everything but Blue.

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Happy GIMPin’

T.

This installment in my GIMP Beginners series is about Rotating and Cropping images (just as the title suggests). The areas covered being basic orientation (portrait vs’ landscape), straightening horizons, corrective cropping (after leveling of horizons) and cropping to a specific ratio. This tutorial is based on GIMP version 2.6.2.

 
Basic Orientation (portrait vs’ landscape)

So you’ve just opened your image in GIMP but you find yourself placing your head on one shoulder to see it right. There is luckily a one step fix for this problem.

1. From the dropdown menus select Image > Transform and then select Rotate 90 clockwise or counter-clockwise as appropriate.

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Tip: Rotating a .JPG image in this fashion will cause some deterioration in quality. If you are editing an image for use on the internet you will need to rotate it, however if you are editing a file for printing you may wish to simply skip this step and perform your edits in the default orientation, your printer will not know any differently.

 
Straightening Horizons

Now check to see that the camera was level when the shot was taken, the best check for this is the horizon. If your horizon sloping to one side or all your buildings are leaning to the left or right proceed as follows.

1. Move you mouse to an area roughly in the center of the horizon and note the coordinate given at the lower left corner of the image window.

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2. From the dropdown menus select Image > Guides > New Guide…

3. In the resulting ‘Script-Fu New Guide’ dialog box select Horizontal from the dropdown box and enter the number which we memorised in step 1, then click OK. (If you are using a building to test the straightness you will select Vertical from the dropdown and enter the number from the left rather than the right).

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4. From the Toolbox select the Rotate tool and mouse click anywhere in your image.

5. In the ‘Rotate’ dialog box change the Angle until the horizon runs parallel to our guide, click OK when you are done.

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6. Now turn off your guides by selecting Image > Guides > Remove all Guides.

Tip: If you are using a building it is best to select one from near the center of the photo. This is due to the fact that some camera lens (wideangle) may cause buildings to slope inwards as they rise, this is called “converging verticals”, I have a feeling that we’ll be coming back to this is a later installment.

 
Corrective Cropping

If you have rotated your image in order to straighten it corrective cropping will your next step. To do this

1. From the Toolbox select the Crop tool. To keep the cropped image the same basic shape as the original make sure to select Fixed for ‘Aspect Ratio’ in the tool options.

2. Using your mouse, click and drag to roughly the size you wish to crop, you can now fine tune the crop area by using the mouse to drag the sides of the area to their final positions. When you are happy go back to the ‘Crop’ dialog box and click OK.

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Cropping to Specific Ratio

There will of course be time when you wish to use cropping to change the basic shape of your image, for instance to fit an 8 x 10 photo frame. To do this

1. From the Toolbox select the Crop tool.

2. Make sure that Fixed is selected for ‘Aspect Ratio’ in the tool options and now use your keyboard to enter “8:10” in the box. You can use the Portrait and Landscape buttons to flip the crop area if needed.

3. Using your mouse, click and drag to roughly the size you wish to crop, you can now fine tune the crop area by using the mouse to drag the sides of the area to their final positions. When you are happy go back to the ‘Crop’ dialog box and click OK.
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Happy GIMPin’

T.

I installed GIMP on a friends machine the other day, this is when I realised that there are a few steps which I carry out before I ever edit a photo. These a just a few small changes to the GIMP’s default setup which make things run a little more smoothly, for me at least. These may be of use to GIMP beginners to help get them up and editing.

OK so you’ve just installed GIMP, if not download it for free at www.gimp.org/downloads and install it as usual. You may wish to look at this post which explains how to set the GIMP’s file association during the install process, or afterwards if you already have GIMP installed.

Note that I am basing this on GIMP version 2.6.2

1. Organising on screen elements

The first thing to do after you launch GIMP is to arrange the onscreen elements to your liking. Here is a screen shot of my own preferred setup. Hint: (Open an image so you can better see where to place the ‘Toolbox’ and ‘Layers, Channels, Paths’ boxes.

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a.) Once you have things arranged to your liking, go to the “Edit” drop down menu and select “Preferences“.

b.) Now go to “Windows Management” and click on “Save Windows positions Now“, ensure that “Save window positions on exit” is checked also and click “OK“. Your windows should appear as you like them next time GIMP is started (you may however need to maximise the image window).

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2. The Grid Feature

The default setting for the grid (a very uesful tool I might add) is too small to be very useful when it comes to the large files from a digital camera. I always like to change the default to a more usable setting.

a.) Select “Edit” > “Preferences” to bring you back to the Preferences dialog and this time select “Default Grid“. in the spacing section change the “Width” and “Height” to 100 pixels (or whatever you personally like) and click on “OK“.

To activate the grid select “View” > “Show Grid“. Repeat the process to turn it off again.

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3. Ensure Best Quality

You may have read that it not good practice to repeatedly save a .JPG file. This is due to the fact that .JPG is a compressed file format, as such the file is recompressed (subsampled) each time the file is saved and this will lead to deterioration of the image.

This step will limit this subsampling as much as possible and should be OK for a few svaes, however as you become more confident I suggest that you only save a .JPG file once, at the end of editing. If you are working on an important file or making a complex edit consider first saving your file in an uncompressed format, such as .TIFF or the GIMP’s native .XCF, and save to your hearts content.

a.) Open a .JPG file and select “File” > “Save As…“. In the ‘Save Image’ dialog box enter a junk filname and click on “Save“.

b.) In the ‘Save As JPEG’ dialog’ click on “Advanced Options“. Now change the “Quality:” slider to 100% and change “Subsampling” to 1X1, !X1, 1X1 (best quality). then select “Save Defaults“. You can now click on “Cancel” as we do now want to save this image at this time.

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4. Use the Historgam

For photo editing I like to add the ‘Histogram’ dialog available as a reference. This setup guide is not really the place for a detailed explanation of what the image histogram is but, simply put the Histogram is a graphical representation of the tones in an image from pure Black on the left to pure White on the right.

As such it gives us some information about the exposure. If we see that the graph is clumped to the left, it suggests that the image is too dark (underexposed) and if we see that the graph is clumped to the right it suggests that the image is too bright (overexposed).

a.) To add the ‘Histogram’ dialog to your ‘Layers, Channels, Paths’ box select “Windows” > “Dockable Dialogs” > “Histogram“. this opens the ‘Histogram’ dialog in a new window.

b.) Now with your mouse grab the ‘Histogram’ dialog and drag and drop it onto the bottom of your ‘Layer, Channels, Paths’ as shown below.

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5. Restoring Closed Docks

AAArrghh!, where’s that Layers thingy gone?. I have had this same experience myself. If you accidentally close the ‘Toolbox’ or ‘Layers, Channels, Paths’ boxes select “Windows” > “Recently Closed Docks” > “Whichever you closed“, and your back in business.

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Happy GIMPin’,

T.