A simple approach to HDR-blending - Revision history

Erik Krause: 1 revision(s)

2007-03-21T18:09:00Z

1 revision(s)

Bruno: switched photomatix link

2007-03-21T18:07:00Z

switched photomatix link

Bruno: switched photomatix link

2006-08-18T10:53:15Z

switched photomatix link

Jdsmith at 06:31, 21 July 2006

2006-07-21T06:31:01Z

WikiSysop: 8 revision(s)

2006-07-13T20:27:58Z

8 revision(s)

WikiSysop: 1 revision(s)

2006-07-13T19:56:38Z

1 revision(s)

Erik Krause: categorized

2005-11-12T16:32:03Z

categorized

Erik Krause: categorized

2005-11-12T16:32:03Z

categorized

New page

<h2> or: Getting rid of ugly blending halos </h2>

=== Intro ===

One of the biggest problems in panoramic imaging is the typical high dynamic range of the scenery.
Many commercial applications address this problem but the higher the brightness differences are, the more images you need to blend to get a sophisticated result.

This tutorial addresses the generation of a blended image from 2 shots in general - with a special focus on reducing the resulting blending halos.

=== Preparation: How to shoot the images ===
[[Image:Dark.jpg|thumb|250px|The "dark" image]] [[Image:Light.jpg|thumb|250px|The "light" image]]

If your camera can do spot-metering, enable it. This will help you to measure the exact spot which you want to use for your different images. If your camera has no spot-metering, shoot the image and check it thoroughly if it fits your needs.

The "light" image:
This image will hold the information about the darker areas of your blended image. Capture it without caring about the bright areas in your image. It should look like a "normal" photo.

The "dark" image:
The enemy of digital photography is over-exposure. You need to avoid an overexposed image under any circumstances. You can restore pretty much out from darker areas in your digital image, but you can't restore any information out of a bright white area.
To avoid over-exposure, expose towards the brightest areas in your image.
{{clr}}

[[Image:Blended.jpg|thumb|250px|A standard blended image]]
=== Standard blending process ===
This is how a standard blending process will look like. Please notice the strange halo around the lamp. We're going to avoid this.
{{clr}}

===Processing the images===
==== Step 1: ''Blending'' ====

Several ways exist to blend the images together for a nice visual appearance: GUI-based with a software like [http://www.hdrsoft.com/ Photomatix] - [[Contrast Blending|Contrast Blending (Exposure Blending)]] - or some manual work with Photoshop as described below...

Load both images and copy the dark image as a separate layer over the light image. Add a layer mask with the dark image completely masked out.

* As you can see there are "burnt out" white areas in the light image. All the following steps have to be done separately for each coherent white area in the image.

[[Image:Brush1.jpg|thumb|250px|Example brush size]]
* Prepare a layer brush (=the normal brush) with soft edges and a radius which is a little larger than the area you want to get from the dark image. You can see an example of the brush size for the large area here:
{{clr}}

[[Image:Brush2.jpg|thumb|250px|Light areas blended from the dark image]]
* Click to "paint through" and don't care if the brightness doesn't fit perfect. This will be addressed in the next step.
{{clr}}

[[Image:Brush3.jpg|thumb|250px|Blended areas with brightness adapted]]
* Now adjust the color saturation of the blended areas. Reduce your layered image to one layer. Use the Sponge Tool (Photoshop shortcut: O) in saturate mode with a strength of about 10% to carefully adapt the color saturation:
{{clr}}

====Step 2: ''Removing color halos''====

Now we have to eliminate the resulting color halos for a correct image appearance. This step may sound complicated but is very straightforward as soon as you are used to the process.

[[Image:Final.jpg|thumb|250px|The final image - Color halos are removed]]
* Use the eyedropper tool to retrieve a color sample of the surrounding area where the colors are still correct. Use a multi-point matrix to have a good color sample.
* Now select the brush tool. Switch the painting mode from "Normal" to "Saturation". Paint over the color halo. Don't be irritated if the color becomes worse than before.
* Switch the painting mode from "Saturation" to "Color". Paint over the color halo.
* If you feel that colors are too intense, you may use the Sponge Tool (Photoshop shortcut o) in desaturate mode to carefully reduce the colors. A tool-strength of about 10% is strongly suggested.

--[[User:Bvogl|Bvogl]] 16:50, 18 Jul 2005 (EDT)

[[Category:Tutorial]][[Category:Tutorial:Nice to know]]

Zarl: /* Standard blending process */ typo

2005-11-03T10:56:23Z

‎Standard blending process: typo

Erik Krause: Changed layout from table based to CLR template

2005-09-05T21:36:37Z

Changed layout from table based to CLR template

← Older revision		Revision as of 18:07, 21 March 2007
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	--[[User:Bvogl\|Bvogl]] 16:50, 18 Jul 2005 (EDT)		--[[User:Bvogl\|Bvogl]] 16:50, 18 Jul 2005 (EDT)

−	~~[[Category:Tutorial]]~~[[Category:Tutorial:Nice to know]]	+	[[Category:Tutorial:Nice to know]]

← Older revision		Revision as of 16:32, 12 November 2005
Line 58:		Line 58:

	--[[User:Bvogl\|Bvogl]] 16:50, 18 Jul 2005 (EDT)		--[[User:Bvogl\|Bvogl]] 16:50, 18 Jul 2005 (EDT)
		+
		+	[[Category:Tutorial]][[Category:Tutorial:Nice to know]]

@@ Line 29: / Line 29: @@
 ==== Step 1: ''Blending'' ====
-Several ways exist to blend the images together for a nice visual appearance: GUI-based with a software like [http://www.hdrsoft.com/ Photomatix] - [[Contrast Blending|Contrast Blending (Exposure Blending)]] - or some manual work with Photoshop as described below...
+Several ways exist to blend the images together for a nice visual appearance: GUI-based with a software like [[Photomatix]] - [[Contrast Blending|Contrast Blending (Exposure Blending)]] - or some manual work with Photoshop as described below...
 Load both images and copy the dark image as a separate layer over the light image. Add a layer mask with the dark image completely masked out.

@@ Line 3: / Line 3: @@
 === Intro ===
-One of the biggest problems in panoramic imaging is the typical high dynamic range of the scenery.
+One of the biggest problems in panoramic imaging is the typical high [[dynamic range]] of the scenery.
 Many commercial applications address this problem but the higher the brightness differences are, the more images you need to blend to get a sophisticated result.

← Older revision	Revision as of 20:27, 13 July 2006
(One intermediate revision by one user not shown)

@@ Line 23: / Line 23: @@
 [[Image:Blended.jpg|thumb|250px|A standard blended image]]
 === Standard blending process ===
-This is how a standard blending process will look like. Pleace notice the strange halo around the lamp. We're going to avoid this.
+This is how a standard blending process will look like. Please notice the strange halo around the lamp. We're going to avoid this.
 {{clr}}

@@ Line 1: / Line 1: @@
-== or: Getting rid of ugly blending halos ==
+<h2> or: Getting rid of ugly blending halos </h2>
 One of the biggest problems in panoramic imaging is the typical high dynamic range of the scenery.
@@ Line 6: / Line 8: @@
 This tutorial addresses the generation of a blended image from 2 shots in general - with a special focus on reducing the resulting blending halos.
-----
+=== Preparation: How to shoot the images ===
-{|
+[[Image:Dark.jpg|thumb|250px|The "dark" image]]  [[Image:Light.jpg|thumb|250px|The "light" image]]
-| '''Preparation: How to shoot the images'''
 [[Image:Dark.jpg|thumb|The "dark" image]]  [[Image:Light.jpg|thumb|The "light" image]]
 If your camera can do spot-metering, enable it. This will help you to measure the exact spot which you want to use for your different images. If your camera has no spot-metering, shoot the image and check it thoroughly if it fits your needs.
@@ Line 19: / Line 19: @@
 The enemy of digital photography is over-exposure. You need to avoid an overexposed image under any circumstances. You can restore pretty much out from darker areas in your digital image, but you can't restore any information out of a bright white area.
 To avoid over-exposure, expose towards the brightest areas in your image.
-|}
+{{clr}}
-----
-{| width=100%
-| This is how a standard blending process will look like: [[Image:Blended.jpg|thumb|A standard blended image]]
-|}
-----
-'''Processing the images:'''
-Step 1: ''Blending''
+[[Image:Blended.jpg|thumb|250px|A standard blended image]]
 Several ways exist to blend the images together for a nice visual appearance: GUI-based with a software like [http://www.hdrsoft.com/ Photomatix] - [[Contrast Blending|Contrast Blending (Exposure Blending)]] - or some manual work with Photoshop as described below...
-{| width=100%
+Load both images and copy the dark image as a separate layer over the light image. Add a layer mask with the dark image completely masked out.
-| Load both images and copy the dark image as a separate layer over the light image. Add a layer mask with the dark image completely masked out.
-|-
-| * As you can see there are "burnt out" white areas in the light image. All the following steps have to be done separately for each coherent white area in the image.
-|-
-| * Prepare a layer brush (=the normal brush) with soft edges and a radius which is a little larger than the area you want to get from the dark image. You can see an example of the brush size for the large area here:
-[[Image:Brush1.jpg|thumb|Example brush size]]
-|-
-| * Click to "paint through" and don't care if the brightness doesn't fit perfect. This will be addressed in the next step. [[Image:Brush2.jpg|thumb|Light areas blended from the dark image]]
-|-
-| * Now adjust the color saturation of the blended areas. Reduce your layered image to one layer. Use the Sponge Tool (Photoshop shortcut: O) in saturate mode with a strength of about 10% to carefully adapt the color saturation:
-[[Image:Brush3.jpg|thumb|Blended areas with brightness adapted]]
-|}
-Step 2: ''Removing color halos''
+* As you can see there are "burnt out" white areas in the light image. All the following steps have to be done separately for each coherent white area in the image.
 Now we have to eliminate the resulting color halos for a correct image appearance. This step may sound complicated but is very straightforward as soon as you are used to the process.
 * Use the eyedropper tool to retrieve a color sample of the surrounding area where the colors are still correct. Use a multi-point matrix to have a good color sample.
 * Now select the brush tool. Switch the painting mode from "Normal" to "Saturation". Paint over the color halo. Don't be irritated if the color becomes worse than before.
 * Switch the painting mode from "Saturation" to "Color". Paint over the color halo.
 * If you feel that colors are too intense, you may use the Sponge Tool (Photoshop shortcut o) in desaturate mode to carefully reduce the colors. A tool-strength of about 10% is strongly suggested.
 --[[User:Bvogl|Bvogl]] 16:50, 18 Jul 2005 (EDT)