Repairing Blown-Out Highlights with Inpaint

Inpainting refers to repairing or reconstructing portions of an image.  That area may have been damaged in some way or the image may include unwanted content.  Modern image editing software often offer options to automatically repair these sorts of image defects by using an Inpaint plug-in or filter.


Example of Inpaint

I use GIMP when editing images.  It's free to use and offers a large array of image editing options.  Inpaint is not included as part of the basic program, but can be added through plug-ins.  The G'MIC plug-in offers over 500 additional filters, including three different inpaint options.  I will be using one of these filters in this example.  (Inpaint filters are similar enough that the example will help illustrate how Inpaint filters work independent of program.)

 Here's the starting image chosen for this example.  It's a shot of a mushroom growing in a pile of old leaves in my yard.  There is a large area with blown-out highlights at the top of the image and the image could be drastically improved by eliminating that patch.

Note: blown-out highlights are not the only areas that can be repaired by Inpaint.  It just happens to be the reason for using it with the above image.  Also, Inpaint is not the only method available for addressing these sorts of image problems.

The example here will use the G'MIC patch-based Inpaint filter.  G'MIC also offers solidify and diffusion based filters.  I found the diffusion Inpaint filter to be far too time consuming to actually use and the patch-based filter produced far better results than solidify.

Using the Filter

Step 1.  Define the Area
This tells the software what portion of the image should be effected by the Inpaint filter.  The G'MIC plug-in for GIMP offers three methods of defining the area to be effected. 

One method applies Inpaint to transparent areas.  For this type of filter, simply erase the area to be affected.  (Make sure the image has an alpha channel first if not enabled by default.)

The second applies the filter to a particular color.  The area affected needs to be replaced with that color.  The actual method used is not important, but it must involve no feathering.  Feathering will result in part of the color being left behind after the filter is applied.

The third method uses a second transparent layer.  The area to be affected is painted in.  The filter then applies the effect to the areas under the opaque portion of this layer.  The color used for marking the area is not important.  It just needs to be opaque.


Other programs may utilize a different method for marking the area for the filter. 


Applying the "mask" for the filter.

Here the area has been marked using red by using GIMP's pencil tool set to 100% hardness to avoid feathering.

Step 2.  Run the Filter
In GIMP, the G'MIC plug-in filters are accessed by selecting filters on the top menu bar and then scrolling down to the bottom of the filters list.  G'MIC is listed at the bottom.  Clicking on it starts the G'MIC plugin and brings up all the filter options offered by that plug-in.

The Inpaint options are listed under "Repair".  Click on that option to expand it.  Scroll down until the Inpaint options are listed and select "Inpaint [patch-based].   This brings up the filter and its options.  (I just use the default settings.  They work fairly well and there is little documentation on the settings.)

After running the filter:

Better, but definitely not perfect.  The area isn't as distracting now, but there are obvious artifacts.  This leads to...

Step 3. Improve the Results
There are times when the results from running an Inpaint filter need no adjustment.  In this case, the area has obvious problems that need addressing.

Smoothing the area:

Followed by cutting and pasting leaves from other areas:

The pasted leaves are partially transparent and the edges feathered for better integration.  Part of the area filled by the Inpaint filter are still visible.


Why Use Inpaint

Using Inpaint can be useful, even if the results need to be altered after running the filter.  In the above example, Inpaint produced vague leaf-shaped results which provided a good background for manual steps.  Inpaint produced this background far quicker that doing so manually.

Combining copies of other parts of the image with this background helps limit the obvious nature of this fix.  This is one advantage of using Inpaint.  Even if the results aren't perfect, the results can be combined with other methods used to correct image flaws and the results may be better than utilize one method by itself.


One bit of advice on using Inpaint.  Keep the area selected fairly small.  200-300 pixels in diameter is a good limit on my system.  (Computers with faster processors or more memory may be handle larger areas.)  The filter can be applied in stages if dealing with larger areas.

If dealing with multiple areas, apply the filter to one area at a time.

LED Light for Photo Studio

Shutterbug has a review for the Rotolight Anova LED EcoFlood.  This is an LED designed for used in photography studios (or for shooting videos.)

The EcoFlood combines 576 LEDs to produce an the same amount of light as produced by a 1000 Watt tungsten bulb.  In comparison, the EcoFlood consumes 38 Watts of power.  The EcoFlood also produces little heat, unlike tungsten lighting.  (They're called "hot lights" for a reason.)

The low power consumption and lack of heat makes this an attractive alternative to tungsten lighting for continuous light production. 

It is a bit pricy at $2600.  Definitely targeted at professional photographers at that price.

Check the review for a full description.

New Interchangeable Lens Camera From Sony

Sony has announced the release of a new addition to their Alpha line of Interchangeable Lens Cameras.

The a7 (Alpha 7) is a light-weight mirror less camera with a full-frame 24.3 MP sensor.  The camera is capable of storing images in 14-bit RAW format and ships with a 28-70mm lens.

The camera is capable of using Sony's current E-Mount lenses, but the deference in sensor size will impact the results of using one of those lenses.  The are currently only a limited number of E-mount lenses designed for use with a full-frame sensor.  Sony does plan in introducing more lenses over the next two years.

Adapters for other lenses are in the works as well.

Price for the kit is currently set at $1999.

Sony also plans a version with a 36.3MP full-frame sensor (the a7R)  This is slated to be available at the same time as the 24.3MP version.  The 24.3MP a7 is available for pre-order on Sony's website.  The a7R is not listed for sale at this time.

Types of Artificial Lighting Used in Photography

Artificial light sources allow photographers to shot without having to depend on the natural lighting conditions present.  Increasing the amount of light present also allows photographers to use lower ISO settings which decreases noise and grain, producing higher quality images.


Continuous Lighting

Continuous lighting remain designed to stay on for long periods.  Continuous lighting allows a photographer to see how the light will influence a shot before actually triggering the shutter release.  The shot can be carefully composed to produce the exact image desired.

The drawback?  Continuous lighting sources tend to be less powerful than flash sources.  The photographer may still need to use a higher ISO or slower shutter speed than required with flash photography.  Whether this matters depends on the subject being photographed.  A slower shutter speed makes little difference when subject that are immobile but may matter with live subject, like small children.

There are various types of continuous lighting sources available.  Each has advantages and disadvantages.


Incandescent Light

The original source of artificial light.  Incandescent lights work by passing an electric current through a filament that resists the flow of electricity.  This resistance causes the filament to heat up.  It glows as a result of heating up.

This is the main drawback of using incandescent light sources.  They are inefficient when it comes to light production and they produce heat..  Much of the energy is lost as heat instead of producing light.  (There is a reason why toasters, electric ranges and electric kilns use this method to produce heat.)

Incandescent lights produce "warm light" meaning they produce light with a yellow or orange cast.  The exact color temperature depends on the type of light involved.

Incandescent lights designed for home use have a color temperature around 2800K.  Halogen lights have a slightly higher color temperature (3000-3400K).

Halogen lights produce more light and heat than regular household incandescent lights.  They require the use of quartz instead of glass to deal with the heat produced by the filament.


Fluorescent Light

Fluorescent lights work by using an electrode to stimulate a small amount of mercury in a sealed tube.  This causes some of the mercury to turn into a gas.  The electrons flowing through the tube collide with the electrons of the mercury gas.  These electrons emit light when they lose the extra energy gained from this collision.  The mercury gas primarily produces ultraviolet light.

The inside of the glass tube is covered by a powder that fluoresces (produces light) when exposed to ultraviolet light.  The fluorescent coating can be altered to vary the color of light produced.   Fluorescent light bulbs typically produce "warm white" light (3000K) or "cool white" light (5000K). 

Fluorescent lights are more efficient than incandescent requiring less energy to produce a similar amount of illumination. 

The mercury used in fluorescent lights can pose a health hazard if the bulb is broken and there are disposal issues involved in the use of fluorescent lights.  They also don't emit light consistently across the entire light spectrum.  This can cause a greenish cast when shooting under fluorescent lights.  This can also cause certain colors to be rendered inaccurately.


LED Lights

Light Emitting Diodes are the latest edition to the artificial lighting market.  LED technology has been around since the 1960's but have not been suitable for producing large amounts of light until fairly recently.

Light Emitting Diodes work by passing a current across a semiconductor.  The semiconductor emits light as a result of the electric current.  LED lights are more efficient than both incandescent and fluorescent lights.  The light produced is a direct result of the electricity supplied to the LED.  Very little energy is wasted as heat. 

LED lights also offer the advantage of being able to produce a specific wavelength of light.  LED lights can produce infrared, ultraviolet or visible light of any color simply by altering the semiconductor used. 

The main problem with LED lights right now is price.  They cost much more than the alternatives, but this is changing fairly rapidly. 

LED lights also struggle to provide light consistently across the light spectrum.  Like fluorescent lights, LED lights can produce a color cast or cause colors to be rendered inaccurately.


Even with the drawbacks, LED lights fill a useful roll in photography at present.  The very low power use couple with the small size of the diodes makes LED lights well suited for portable light sources.  A rechargeable LED light panel can provide light for several hours of constant use and can provide useful amounts of light.


Flash Lighting

Flash lighting produces a bright burst of light that lasts for a short period of time.  Flash units require less power overall than consistent lighting.  They do require power to be released in more powerful bursts.

Modern electronic flash units work by applying a large voltage charge to ionized xenon gas.  The electrons in the xenon atoms get a boost from the charge and then emit light as they lose this extra energy.  This is similar to how fluorescent lights work, but the xenon gas produces visible light instead of producing light that is mostly ultraviolet in nature.

Flash units have drawbacks. 

Flash units require a burst of high voltage to work correctly.  This means storing energy up over time.  This makes the flash unit unavailable as a light source while this charge is building.

Flash units can cause red eye when photographing living subjects.  This can be addressed using software.

Flash units powerful enough for studio use can also be very expensive.  There are inexpensive alternatives, but these have drawbacks as well.  The least expensive alternative uses individual flash units.  Each unit has to be plugged into a different outlet which can be a problem if multiple lights are desired.

Why We Use Temperature to Describe Light Sources

Photographs are impacted by the lighting conditions that exist at the time the photo is taken and photographers need to consider this impact when shooting pictures.

Modern digital cameras provide options for compensating for different lighting conditions.  Usually the options include multiple presets described based on the type of lighting present.  These settings include daylight, incandescent and fluorescent with other options present on many cameras.  Some cameras offer the ability to manually set the camera's color correction.  (Described as setting the white balance since the photographer is telling the camera that a specific color should be rendered as white.)

Determining what setting to use does require knowing a little about the quality of light involved.


Describing Light

Light is described using a temperature scale.  There is an historic reason for this that dates back over 100 years to the work of Lord Kelvin.

The Kelvin temperature scale is used when describing the color or quality of light produced by a particular light source.  The Kelvin scale is the same as the Celsius scale, but adjusted so starting point is absolute zero instead of the freezing point of water.  Subtract 273 from the Celsius temperature to get the Kelvin equivalent.

Why Temperature?

Credit Lord Kelvin for this.  He is the one that developed a system of describing light sources based on temperature.  Lord Kelvin started by heating a piece of carbon.  Carbon glows when it is heated and the color produced depends on the temperature to which the carbon is heated.  It starts at a dark red, shifts to a brighter red, then orange, followed by yellow, white and then shifts to blue.

Lord Kelvin then assigned light sources a temperature number based on the temperature to which carbon had to be heated to produce a similar light.

The quality of light produced by a particular source is described using temperature based on this work by Lord Kelvin.  (The modern value is based on theoretical physics and a "black body" instead of carbon.)   Both natural and artificial lighting conditions can be described using this method.

Examples of Temperature Values

Knowing the value assigned to the lighting conditions present when taking photographs can be useful when using a camera with a limited number of lighting presets.  The lighting conditions present may be similar to one of the lighting conditions covered by one of the preset options.  Using this setting may result in better results than the camera's automatic white balance results.  (Try the overcast/cloudy sky setting when shooting in heavily shaded areas.)

Some values:

Incandescent light bulb: 2800K
Halogen light:                3000K
Direct Sunlight:             4800K
Cloudy Sky:                 6000K
Blue Sky:                   10,000K (and up)

Fluorescent lights can manufactured to mimic incandescent light or daylight.  Warm white fluorescent lights are rated at 3000K, Cool white or daylight at 5000K.

LED lights can produce a variety of light.  Daylight LED lights produce light in the 5500 to 6000K range.  LED lights that mimic incandescent lights are available as well.

Note on Fluorescent Light:
Fluorescent lights usually produce light that falls outside the black body temperature chart.  Fluorescent lights don't produce light across the entire spectrum.  These missing wavelengths result in a color of light that does not directly correspond to any present in the temperature scale.

The same is true to a certain extent to LED lights.

Another Reason Why Adobe's Subscription Model Was a Bad Idea

As if annoying its customers by switching to a Creative Cloud/Subscription business wasn't enough, Adobe just announced that it was hacked and almost 3 Million customers had their information stolen.

The information stolen includes Credit Card information.  The information was apparently encrypted, which should prevent the thieves from being able to use it.  There is the possibility that the information could be decrypted  (probably not that likely with modern encryption techniques).  There is also the possibility that the thieves managed to access the decrypted Credit Card information.

Adobe has reset the password of any account believed to have been compromised.  Other Adobe account holders may want to change their passwords as well.  Adobe account holders should also keep an eye on the Credit Card used in conjunction with their Adobe account.

This was almost predictable after Adobe forced Photoshop users into cloud computing.  These users had privacy concerns and those concerns have just been realized.  The question is, how many customers will be in a position to leave Adobe for a competing product?

MostPhotos Stock account

I now have an account at MostPhotos.

I currently only have a couple of pictures I took of a 1938 Plymouth loaded on the site.  Interestingly, if you do a search for "1938 Plymouth" it only brings up one result.  Mine.

Don't know how many people are going to search for that term, but I currently have a monopoly on it.

I have more photos to upload.  I just have to decide which ones are appropriate to offer as stock and edit them so they look as good as possible.  I''ll probably try applying to other stock sites later.  MostPhotos does not have a review process for photos offered for sale, unlike other stock sites.