Making New Look Old - Refining Photographs with Gimp

Martin Sommer

Introduction

Many users who have migrated to Linux will surely be familiar with various procedures and tricks for common image editing programs such as Adobe Photoshop or Paintshop Pro. Of course, many of these procedures work in the same manner in Gimp. Individual functions may simply have different names or be located at unfamiliar positions . This article covers a number of procedures that may be useful for editing photographs for web pages. Naturally, these solutions are not exclusive, i.e. the same results can often be obtained in a variety of ways. In the first part we will try to enhance a photograph with a border with a soft transition to white. Additionally, the picture is supposed to look like an old black/white (or rather, sepia/white) photograph.

Refining Photographs

Gimp critics sometimes maintain that this program lacks some of the functionalities that can be found in e.g. Photoshop. This might be true, but in contrast Gimp provides a host of functions not available in any other image editing program. True, Photoshop allows you to write your own macros which consecutively apply several functions to a picture. However, Gimp has a lot of pre-implemented macros at its disposal. These macros - which are located in the first menu (right mouse button) under Script-Fu - are based on Gimp's custom language Script-Fu and can be executed with a simple mouse click. When you test these functions one after another, you will discover incredible effects that you have missed in other image editing programs, or for which much time was needed because they could only be accomplished by means of a complex sequence of filters and effects.

First of all, we will use one of these Script-Fu macros to transform a normal color photograph into an "old" one and furnish it with a border with a soft transition to white. This can be done in no time with a Script-Fu program which will produce very nice results. Yet, unless you are able to modify the script yourself, this procedure is rather unflexible, as you can not adjust the colors, border width, blur intensity, etc. Therefore, this article provides a description of the more complex, but much more flexible procedure for modifying a photograph manually as desired. By the way, a Script-Fu editor which enables you to write your own Script-Fu macros is located under:

Xtns -> Script-Fu -> Console

The Script-Fu "Old Photo"

The sample picture we have used is an extract of a picture from the "Linux 2.5 Kernel Summit" in Spring 2001 in San Jose, California.

Start Gimp, open the picture to be edited and click on it with the right mouse button. Then select

Script-Fu -> Decor -> Old Photo

Mark the following options: Border (creates a white border with a soft transition), Sepia (changes the colors to sepia/white), Work on Copy (applies the effect to a copy instead of the original). By activating Defocus the photo will appear older. By default these four points are usually marked. Confirm by clicking on OK - there you are!

Manual Procedure

The "aging" process is performed as follows: First, apply a very light blur to the picture, remove the colors, and modify the colorscale (or grayscale) by means of a filter. Then, turn our attention to the border: Duplicate the layer, select the border, cut out the inside, change the border color to white, and modify it with the Gaussian Blur.

The best way to obtain a light blur is to use either the Gaussian Blur or the Motion Blur. The option Blur can be found under Filters -> Blur. In the case of Gaussian Blur, the radius in both directions should be approximately 3 pixels. As for the Motion Blur, the suitable settings are Linear, Length 4-5, Angle 0. Needless to say these are reference values and you are free do select your own settings.

Continue by removing all colors, i.e. decrease the hue saturation by selecting (again with the right mouse button):

Image -> Colors -> Hue Saturation

The option Master must be activated. In order to visualize the effects directly, the option Preview, too, should be selected. Set the saturation slider to -100 and press OK. Now the picture is black/white.

In order to modify the colors (grayscale) select:

Image -> Colors -> Filter Pack...

The settings on the left remain unchanged, on the right side we click on Hue. A pop-up window displaying the picture various color filter options appears. The really tricky thing is to find the right combination or sequence of color alterations. This means that several changes can be applied successively, and each of them will be superimposed on the previous one. At this point you should try to find out what produces the best results. To start off you should reduce the Roughness to 0.10, so that alteration steps are not too dramatic. Then try out the following combinations (just click one after the other):

• red -> green
• yellow -> red
• yellow -> red -> yellow
• yellow -> red -> cyan
• yellow -> magenta -> green

Save the result under a different name, preferably in Gimp format (extension .xcf).

Screenshot: Filter Pack for altering the B/W picture

Result: B/W picture in old sepia shades, color alteration: yellow -> red -> yellow, Roughness: 0.10

The Border Transition - Basics of Working with Layers

The first stage has been reached and the picture colors now resemble a photograph from the turn of the century. Now the border needs to be blurred. This requires the use of layers, so you should have some experience with layers. If the layer window is not open yet, please open it in the Dialogs menu (by clicking on the picture with the right mouse button or by selecting Files-> Dialogs in the main menu). If your picture is in jpeg or tiff format, it consists of a layer called Background after it is opened. This is also the case if you have followed the above steps and saved your picture in xcf format. The background layer is "off-limits", i.e. it is a security image that should never be edited. As a cautionary measure, the actions that Gimp allows on the background layer are quite limited.

Accordingly, the layer needs to be duplicated. This can be done by dragging it with the left mouse button to the double-page symbol below (in the layer window). The duplicate will be displayed above the original one and is called Background copy. You can rename it by double-clicking on it. Now repeat the procedure once more so that you have two copies of the picture. Hide the original (background layer) by clicking on the eye located on its left. You can only work on the layer that is highlighted in blue by clicking on it.

Caution:
Individual layers are often hidden/displayed in order to see the effects which have been applied. It can easily happen that one layer is visible while another one is invisible but active. This means that you actually work on the hidden layer while seeing the one that is not being edited. After a while you will wonder why you cannot see any effects, until you realize (often too late) that you have been working on the wrong layer. In most cases you can just as well discard the layers in the trash (lower right corner of the layer window).

Now hide the lower of the two visible layers. The top layer (currently the only visible one) must be active. Clicking on the rectangular selection tool and select a section inside the picture, leaving only a narrow outer border. Delete the selected inner section with STRG+K or using the menu Edit -> Clear. Then mark the remaining border by reversing the selection (menu: Select -> Invert). The border will be filled with white (or the color of your choice, see below). The main menu will show whether white is the foreground or background color (black/white double page). If it is e.g. the foreground color, select: Edit -> Fill with FG Color.

Tip: Choose Your Color
If you want to integrate the picture in a web page with a color background, you should use the color surrounding the picture. To do this open your web page or a file containing the color and make a screenshot with Gimp. Screenshots can be made with File -> Acquire -> Screenshot in the main menu. Once the screenshot is available, select the pipette tool from the main menu and pick the color you like. It will be displayed in the "double page" as foreground color. Now you can close the screenshot.

Then, deselect the selection with Select -> None. To obtain the blur effect, select Filter Packs -> Blur -> Gaussian Blur (both types are suitable). Set the radius to 25-35 pixels and confirm with OK. The result is a soft transition in the white border. Now make the layer below visible - voilà, the picture is ready.

You can add the final touch by letting the picture look even older, as it still looks relatively new. For this purpose, "noisify" it with

Filter -> Noise -> Noisify

Disable the Independent button and increase the sliders to about 0.1. After confirmation with OK, the picture has the coarse appearance of an old film. The achieved result truly resembles a very old picture.

Save

As long as several layers exist, the image is in Gimp format, even if it is called .jpg. When you save it in .jpg format, the layers will be merged. (You can also merge them manually: Click with the right mouse button on the layers window -> Merge visible layers). When saving as .jpg, select Export in the next window. The compression window will be displayed. The quality slider allows you to define how much space your picture will occupy (this will is displayed at the upper left of the window). Confirm with OK and you're done!

Summary: Admittedly, the latter method is much more complex than the Script-Fu. However, it is infinitely more flexible and it does not put any limits to your imagination. For example, try to get the blurred border by using the oval select tool instead of the rectangular one. In this way the picture will have the typical shape of the days you want to recreate, and a much more authentic look...