Monday, April 23, 2012

How to "Miniaturize" A Photo



Is this real or a scale model? Fooled ya, didn't I? No, this is not a scale model you are looking at, but a real-life scene taken at an upstate apple farm a couple of years ago. Using some image manipulations in Photoshop it is possible to create the impression that something is very small using something that is very big.

When looking at a photo, the visual cortex interprets various cues in the image to give the viewer a sense of scale, proximity and space, as well as a sense of live reality. Among them are depth of field, color saturation, the rate of sharpness falloff from front to back, lighting intensity and direction, contrast , point of view - to mention a few.

Depth of field is an important clue. Images of large areas with great depth that are sharp from foreground to background suggest a large space, and you are, in a sense, removed from the immediacy of the setting. Sort of like looking through a window onto the scene. A very shallow depth of field suggests intimacy and closeness where distances are measured in inches and fractions of inches.

Using a point of view  that looks down enhances the impression of smallness, since scale models are rarely seen at what would be ground level (in scale, of course).

Color Saturation is another important cue. In scale models colors are highly saturated and vibrant. Model making materials and colorants usually come this way. But another contributing factor is the intense, directional light that models are often viewed under.

Models of exterior spaces in particular lack the diffuse skylight and "radiosity" that enriches illumination in real life. In simplest terms, radiosity is the diffuse light that is reflected from surfaces in a scene. And this light can be either direct or reflected as well.  Think of sunlight coming through a window - there is a shaft of light falling on a wall or a floor, but the entire room is illuminated, even dark areas under tables and chairs, and shadows are very soft in areaas that are not directly lit. By increasing the contrast the impression is created that there is a single strong and directional light source. Here are a couple of illustrations that might help to explain this phenomenon. The first is an example of ray tracing vs radiosity in a computer generated image, the second is a series of examples when radiosity is progressively applied to a simply lit image.

borrowed from Wikipedia article on radiosity http://en.wikipedia.org/wiki/Radiosity_(computer_graphics)


borrowed from Wikipedia article on radiosity http://en.wikipedia.org/wiki/Radiosity_(computer_graphics)


I've created a simple tutorial that explains how to create a "miniaturized" scene in Photoshop. Load an image that has a high vantage point, some foreground and background, and a focal point in the middle. Here I will be creating a plane of focus that includes the two buildings in the middle left, and the orange tree in the middle right.


I Press Q or select Quick Mask Mode. I use this to define the areas that will receive a lens blur filter and those that won't.



I Select The Gradient tool, or press G. This will apply a graduated mask, with a maximum density that will hold back the blur effect which fades to clear, allowing the full effect to be applied to the image.


I pick the Mirrored Gradient tool option. This will create a blurred area above and below the center, with the effect fading to zero in the exact middle, much as how a lens with limited depth of field would record the image.


The kind of mask I will use will fade the foreground color, black to background color, white. Check to make sure these are correct at the bottom of the toolbar.


I left click in the center of the image, the area that I want to be in focus. Holding the mouse button I press Shift to restrict cursor movement to 90 deg vertical, and drag upwards. This will be mirrored, so the amount of movement up is duplicated below the starting point. When I release the cursor, I see a band of red, the default mask color, with the greatest density horizontally across the image at the starting point of the drag and click operation.



I press Q to remove the mask, revealing the "marching ants" designating the areas that will be blurred.




I use the lens blur filter to create a realistic blur in the image.Here its best to play with the settings in preview. A word of warning - the more realistic you want the blur effect you are looking for, the longer it will take to process. The preview really helps here.




When I get it the way I want, I click OK and take a break while Photoshops calculates and applies the effect.



Scale models use materials that have highly saturated colors, so I open the image adjustment Hue Saturation and Lightness command and kick up the saturation a bit. While I am here, I make a slight adjustment to the brightness level.










Last finishing touch is to apply a little vignette in the Lens Correction filter.





It's that easy! Except for the lens blur calculation, it doesn't take much time at all.

Here is another example.


This is a lot of fun, plus it gives you a chance to explore some features in Photoshop that you will be able to use in other situations. Enjoy!





























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