Thursday, November 13, 2014
Thursday, August 9, 2012
Southern Exposure
In this short lesson you will learn a quick, easy procedure to use when you need to recover a badly underexposed photograph. A photograph is described as underexposed when there is not enough light in the photo, so it has a loss of shadow detail. This GIMP tutorial is based on a method described by Dave Johnson in PCWorld.
Open the image you want to make a bit more presentable.
Duplicate the background layer (right-click on the layer and select Duplicate Layer or select Duplicate Layer from the Layer menu) so that there are two identical layers in the Layers pallet.
Be certain the duplicate layer, [image name] copy, is the active layer. From the Colors menu select Hue-Saturation... . Slide the Saturation control left to reduce the saturation to -50.
Again from the Colors menu, choose Invert.
The top layer should now look more or less like the negative of a black-and-white photo.
In the Layers pallet, change the Mode of the duplicate layer to Overlay.
You should now have a somewhat better looking photo than you started with.
I'm going to flatten the image merging the two layers (Image > Flatten Image), and repeat the entire process once more (saturation reduced to -30 this time) to further enhance the image.
Although this isn't a great fix, it will make an underexposed photo much better for casual use, say for Twitter or Facebook, with very little time and effort.
Friday, July 31, 2009
Create a Bright Neon Pattern of Repea...
To complete this exercise you will need to have the GIMP Layer Effects plug-in installed. If you don't have it, you can download it here.
You will also need a simple black-and-white line art shape like these ...
Download either shape or use one of your own. I chose to use the star shape.
Some of the things you'll do in this lesson ...
- Use the Layer Effects tools
- Paste as a new layer
- Move layers
- Rename layers
- Hide and show layers
- Merge layers
- Use the Select by Color tool
- Shrink a selection
- Use guides
1) From the image menu, click Image > Image Properties to get the dimensions of your chosen shape image. As you see, the star image is 479 pixels high by 455 pixels wide.
2) You're going to create a new image (File > New...) based on multiples of these dimensions. To get the height of the new image, multiply the star's height by 1.2. 479 x 1.2 = 575. The width of the new image is 4 to 6 times the width of the shape to allow plenty of room to work. If you multiply the star's width (455) by 6, you'll get 2730, or about 2800 pixels.
3) Now return to the star image. Use the Select by Color tool to select the black star shape.
4) Then shrink the selection by 3 pixels, Select > Shrink... .
5) From the star's image menu select Edit > Copy.
6) Now switch to your new image and paste the star as a new layer, Edit > Paste as > New Layer.
You should now see the pasted layer in the upper left corner of the new image.
If, as in the screenshot above, you aren't seeing all of the new image in the window, the key combo Ctrl-Shift-E will fit the entire image into the window.
8) Use the Move tool to slide the star to the right edge of the image and position it roughly vertically centered.
At this point you should rename this layer in the Layers Palette to make things easier to keep sorted out. Double-click on the name "Clipboard" in the layer list and rename it as "blue".
9) drag a Guide down from the top ruler to help you align the rest of the stars.
Now you can begin creating the neon effects using the Layer Effects plugin.
10) First you'll give the star a bright blue outer glow. Script-Fu > Layer Effects > Outer Glow...
Set the Size: to 8 and use the other defaults.
12) Next comes the inner shadow using a darker shade of blue, Script-Fu > Layer Effects > Inner Shadow... . Click on the color swatch in the Inner Shadow dialog, choose a darker shade of blue. I used 00008a. Set the Size: to 8 and use the other defaults.
13) The next step is to merge the three layers of the blue star into a single layer. Make the Background layer invisible by clicking on the eye next to it in the Layers Palette. Right-click on any of the visible blue layers and select Merge Visible Layers... . Use the default settings.
There should now be just a single blue layer. Make the Background layer visible again by clicking where the eye should be.
This is what you should have right now, the black star with a blue glow around it.
Your next task will be to add a second star with a green glow.
14) Repeat step 6 to get another star and position it with the Move tool. Judge the amount of overlap you'd like to your taste. (You should not need to copy the star from the original image again. It should remain on your clipboard throughout this exercise.)
15) Rename this layer "green" as shown previously in step 8.
16) Repeat step 10 to open the Outer Glow dialog.
17) Click the color swatch and choose a bright green. In the example I used 0bf805. The Size: should again be 8, other settings are defaults.
18) Do the inner shadow as in step 12 using a darker shade of green (144716).
19) Hide the non-green layers and merge the three green layers into a single layer (See step 13).
You should now see two completed stars in the new image when you make all the layers visible again.
Continue this process until you've added as many shapes as you like to your new image.
To finish up, you need to paint the Background layer black with the Bucket Fill tool. You may be wondering why I didn't simply create a black background in the first place. I could have done, but manipulating the black stars on a black background ..., well, you see the point :-).
20) Be sure the Background is the active layer in the Layers Palette, the default color swatches are shown in the Toolbox, and the selected Fill Type is FG Color Fill. Now paint the Background layer.
22) Finally, in the View menu, uncheck Show Guides.
You likely have a bit of unused canvas so you'll probably want to crop the image to suit your needs. In the immortal words of Porky Pig,"That's all, f-f-f-folks!"
Hopefully, you've learned something new in this tutorial. If you found it useful, please share it with others. Any constructive comments are appreciated as well as donations through PayPal.