Ultimatte PhotoFusionｪ is bluescreen or greenscreen image compositing and masking software for still photography with the unique ability to maintain all detail in the foreground scene. The mask necessary to produce seamless composited images is generated automatically using the same patented Ultimatte technology as used in the television and motion picture industries.
Minimum Requirements
･ System 7 operating system.
･ Adobe Photoshop 2.0 or higher.
･ Minimum of 12Mb of RAM allocated to Photoshop.
･ 24-bit Color Monitor.
Installation
Photoshop plug-in modules are installed by dragging the icon for the module into the plug-ins folder.
Getting Started
PhotoFusion is an Adobe Photoshop acquire module. You begin the PhotoFusion process by accessing it through the File-Acquire menu in Adobe Photoshopﾕs File pull down menu. The Photoshop functions are not available until you complete the PhotoFusion process. You will exit back to Photoshop the moment you ﾒSaveﾓ or ﾒQuitﾓ the program.
Selecting PhotoFusion via the Acquire menu causes the PhotoFusion interface to open after displaying its introductory screen. The interface is laid out in functional sections. The main image area (viewing area) has an outline box around it. PhotoFusion ﾒsamplesﾓ your choice of Foreground (FG), Background (BG), Mask (also called ﾒalpha channelﾓ) and final Composite image in to this viewing area.
Three button items in the lower right hand corner are used to ﾒLoadﾓ and ﾒSaveﾓ various image choices in and out of PhotoFusion. The ﾒQuitﾓ button will cause PhotoFusion to exit to Photoshop without saving anything. Associated buttons to the left control the choice of image displayed in the viewing area. You can also use the ﾒfﾓ, ﾒbﾓ, ﾒmﾓ, and ﾒcﾓ keys on the keyboard to view the respective image.
PhotoFusion does not actually save a file to disk itself. You end up with an RGB file on the Photoshop desktop to which PhotoFusion assigns a name. You have the option to save this file in any format you wish from within Photoshop. You must however, save the file in Photoshop 2.0 or 2.5 format if you plan to recall the image again in PhotoFusion.
PhotoFusion returns you to Photoshop upon completion of the image compositing process. You can simply save the composite image you create in PhotoFusion, in Photoshop file format, or intercept the PhotoFusion process before the BG has been added to make improvements to the Mask and FG, then return to PhotoFusion for additional flare control adjustments and colorization, and finally addition of the BG. You can create intermediate composite images in PhotoFusion that can be modified or enhanced by the image processing tools available in Photoshop.
Simplified PhotoFusion Process
The PhotoFusion process starts by selecting a FG image. This is the image which was shot against blue or green backings that you plan to combine with a BG to create a new composite.
Step 1: Load the Foreground
･ Load the desired FG image into PhotoFusionﾕs viewing area. The Load button causes the Load Select Window to appear. Items in light grey prevent you from loading the FG and BG files into PhotoFusion out of sequence. Only Photoshop 2.0 or 2.5 file formats will be recognized by PhotoFusion. In this case you should start by pressing the ﾒForegroundﾓ button in the Load Select Window. This choice will be followed by the typical Macintosh file browser dialog window.
Step 2: Load the Background
･ Press the Load button again to load the desired BG image into the viewing area.
PhotoFusion limits your choice of new BG to image dimensions that are equal to, or larger than, the chosen FG image. A new window will appear to guide you in the positioning of the new BG if the image is larger than the FG.
Step 3: Sample the Backing Color
･ Click-and-drag a sample box in the backing color of the FG image that appears in the viewing area. PhotoFusion will compute the average value of the Red, Green and Blue content of this sample and list these RGB values in the lower left hand corner of the interface.
PhotoFusion automatically determines the backing color. Be careful to select an area of backing unobscured by any FG detail (smoke, hair, reflections in glass or shadow areas). Sample should be near important FG detail. It is recommended only one sample be taken. If better results are desired retake the sample from another area. You can clear the image of all the samples, and start the process again by simply pressing the Flush Points button. Normal click-and-drag samples are outlined in yellow in the viewing area.
Step 4: Press the Backing Color Button
･ Pressing the Backing Color button will causes PhotoFusion to create a black and white linear mask of the FG image. The viewing area displays the result of this process. White values in the Mask represent those parts of the FG image that will be replaced by the new BG. Black values of the Mask are those parts of the image that PhotoFusion considers opaque. The white to black/gray levels in-between represent the intensity level of the BG to be combined with the FG.
Step 5: View the Composite Image
･ Press the View Composite button to view the combination of the original FG with the new BG image. This is called the Composite image by PhotoFusion.
Step 6: Save the Composite
･ Press the Save button. Select Composite from the window of choices offered by PhotoFusion. PhotoFusion exits from its Acquire mode and returns you to Photoshop with an RGB image and fourth channel Mask. Use Photoshop to save the image in your choice of file format.
Select ﾒCompositeﾓ to exit PhotoFusion. This is the default choice. The other three choices are used when you wish to intercept the PhotoFusion process. All files saved by PhotoFusion, when you exit the process, are 24 bit RGB images with a Mask (alpha channel) except for the Control File, which is a pure data file. PhotoFusion pre-names the files and attaches extension names by default. You may rename any of the files (with or without an extension attached) if you choose. You must save the Control File first if you plan to interrupt the PhotoFusion process midstream. PhotoFusion exits to Photoshop the moment you save any one of the three image file choices, but not when you save the Control file.
The procedure outlined above will create image composites of exceptional quality and believability, as long as the FG imageﾕs backing color can be reasonably differentiated from the rest of the image---and especially if the FG scene is properly lit. This compositing process also assumes that the color composition of the FG and BG image are properly matched to one another. This is equally important if you are to create a truly flawless composite. Unfortunately, ideal conditions like these are the exception and not the rule. For this reason, PhotoFusion is equipped with a host of controls to enhance the image compositing process. The experienced user can create virtually flawless composites by properly using the array of controls available in PhotoFusion.
Understanding the Mask
The PhotoFusion process uses a patented algorithm to perfectly suppress the presence of the backing color in the FG image. This technique takes advantage of the fact that the ratio of Red, Green and Blue, in the backing color of the FG image, remains relatively consistent throughout---through glass, smoke, in the shadow areas and even in reflections.
Rather than allow the process to rely on the value of any one single pixel color sampled in the image, or a range of colors centered about a given pixel, PhotoFusion averages all the pixels in the sampled area to come up with a nominal value for Blue, Green and Red in the backing color. Your initial goal is to find a sample whose average values of RGB show the greatest range of separation between the target color of the backing and the other two colors. For this reason, you should be very aware of the backing color area you sample in the FG image. The mask that this sample ultimately creates will depend on sampling the backing area appropriately.
The greater the difference in value between the target backing color and the other two colors (as enumerated in the PhotoFusion display in the lower left hand corner of the interface) the easier it is for PhotoFusion to distinguish the backing from the FG subject matter that should remain. For this reason you need to be aware of the effect your sample will have on the final results. In general, the more color separation between the target backing color and the other two colors, the easier it is for PhotoFusion to discriminate between the backing color and any other similar colors that are meant to remain with the FG subject matter.
Typically best results are achieved when the sample is taken near important FG detail such as hair detail. The sample should not be obscured by any FG subject information (hair, smoke, reflections on glass, or shadows falling on the backing).
In effect, the Mask created by PhotoFusion controls the intensity of the BG image in the final composition. Your sample is the reference PhotoFusion uses to determine full level for the BG in the final composite. The new BG combines with the FG at unity gain for all portions of the image that match the brightness level of the sampled area. Likewise the BG darkens in proportion to the darker areas of the backing color. However, the new BG will not increase in brightness beyond unity gain for areas of the backing color brighter than the sampled area. This is a form of artificial level ﾒclippingﾓ used quite often to compensate for unwanted and uneven shading in the FG image.
You must take your first backing color sample while viewing the FG image. Once you create a Mask, you can regenerate the Mask by sampling the image in the viewing area from within any view. The click-and-drag box(s) you make in the viewing area, followed by the pressing of the Backing Color button, cause PhotoFusion to generate a new Mask by referring back to the sample as if it were made in the FG image. In many cases, it is very useful to visualize the Mask from another point of view.
Making Masks and Solving Problems
Overall, the PhotoFusion process faithfully ﾒtracksﾓ the brightness value of the backing color to create a Mask and reproduce the new BG in the composite by adding it to the ﾒProcessed Foreground.ﾓ
There are many times when the backing color in an image may exhibit changes in value due to undesirable factors. An example of this is an unwanted seam , or texture or ﾒgrainﾓ on the backing material that is visible in the FG image---or maybe a shadow that is the by-product of difficult lighting circumstances. These unwanted defects are difficult to distinguish from the parts of the FG image that should remain in the final composite. These kinds of corrections are best made to the picture in Photoshop before it is sent to PhotoFusion. Other times itﾕs more convenient to alter the PhotoFusion mask and processed FG in Photoshop.
Try sampling the backing color from within the Mask view in the viewing area. The advantage to sampling the backing color from this view is that the mask is showing you where improvements may be needed. It is sometimes difficult to differentiate subtle shades of unwanted gradation in the backing color, from the FG view. The gray scale makeup of the Mask, on the other hand, can easily help you identify areas that need to be improved upon. Regenerating the Mask from the Mask View will help you decide when and where you want to convert an undesirable grey area in the Mask to white. Note however, that you are likely to sacrifice detail in the image that would otherwise have the same level of grey had you not made the change.
You can experiment a bit with this technique by resampling the black or dark gray portions of the Mask. (Donﾕt forget to press the Backing Color button after each sample.) The changes you will see in the Mask will begin to give you a sense of the importance of taking the sample in the appropriate part of the picture. Resampling the mask in the slight grey portion of the Mask will cause the Mask to approach pure white---the equivalent of 100% transparency in the final composite.
Throughout all the previous operations, the controls in the upper left hand corner of the interface played no direct role in making the Mask or influencing the final composite. None of the default control values changed under any circumstance. Choose from one of seven control menus located in the upper left hand corner, each with their own set of controls, to manually modify the elements of the PhotoFusion process and the color makeup of the FG and BG image. All the controls initialize to a default set of values.The user determines which control(s) to change to effect the desired changes in the final image.The Matte controls provide solutions for varying the makeup of the Mask. Flare controls provide solutions for reducing the effects of the backing color. Color controls provide solutions for achieving a perfect match of the FG and BG.
All control values are pre-set by PhotoFusion at first. Not until you change these values from their nominal settings, and click on ﾒPreview Allﾓ or ﾒPreview Selectionﾓ, will you possibly see any effect in the composite. The experienced PhotoFusion user will learn when it is best to leave the settings at their default value, particularly values like the Matte Density, and use the retouch tools available in Photoshop.
To reset the controls to default values, hold down the Command key while clicking on the name of the control.
Flare Control
The Flare controls are designed to limit the backing color spill on the FG subjects so that the subjects will appear to have been photographed in a neutral environment instead of one contaminated by the highly saturated backing. The adjustment of these controls should occur after the Matte controls have been set to optimize the mask and edge detail, and before any other color adjustments are made. Flare suppression is automatic and the factory presets represent our guess at the best compromise. For the sake of flawless composites, these controls are the most important to master. Perfecting these adjustments to create the appearance of a neutral environment is absolutely a prerequisite for successful color matching adjustments to follow.
The FG subject matter may include shades of color that approach the same tint as the backing color. Color spill from the backing on the FG subject, that has not been completely removed by the flare removal algorithm, can cause a similar problem. Both will cause the Mask to be something other than pure black in these parts of the FG image. The resulting grey tone in the Mask translates into a slight degree of unwanted FG transparency in the final composition. The picture is said to be ﾒprinting throughﾓ in this area of the composite. PhotoFusionﾕs Matte menu includes an array of controls capable of solving this, and many other problems.
The making of the Mask goes beyond the simple process of sampling the backing color to create this linear black and white signal. In the real world of image compositing, you may face problems such as black ﾒglossyﾓ objects that reflect the backing color, or scuff marks, seams and unwanted shadows in the FG image that, if left untouched, will create an undesirable effect in the final composite. These kinds of problems go beyond the scope of simply re-sampling the color backing in another part of the image in hopes of influencing the makeup of the Mask.
Great care must be taken when using either Black Mask or White Mask functions or when making adjustments to the manual Matte controls. The ideal use of these controls is not necessarily to a fully dense mask wherever the subject was solid. Excessive backing color spill, shiny surfaces or colors that are too similar to the backing color will result in print through. It is possible to use the Matte controls to adjust the density of the mask to solve these problems, but at the same time edges of the FG subject will be darkened because the mask has become darker in the soft linear edges at the same time. The philosophy guiding the use of these controls should primarily be the creation of perfect edges or transparencies with just the right density. Once the matte adjustments have been made and the desired edge and transparency quality has been achieved, any remaining print through on the mask should be filled-in with the paint tools within Photoshop. For this purpose you must save the Processed Foreground or Foreground & Mask, and combine the BG after you complete the mask corrections in Photoshop.
Sometimes the backing color spill is excessive (which can be influenced by lighting, lens flare, subject reflectivity, etc.), and advancing the Matte Density and Black Gloss controls help only marginally and at the same time create undesirable edge effects. When this occurs, it is advisable to take the raw FG image, before any PhotoFusion processing, into Photoshop, go into Color Balance under Image ﾔAdjustﾕ and reduce the color of the backing (blue or green) by 10 to 20 units overall in either Shadows or Midtones. This will reduce the need for overdriving the Matte controls in PhotoFusion.
Whenever Matte Density or Black Gloss have been advanced above their defaults, edges on flesh tones sometimes become too dense and darkening may result. When this occurs it is advisable to reduce the Red Density control to a level where flesh tone edges are again proper. The Red Density control thins the mask in reddish colors. Similarly, the Green Density control thins the mask for greenish colors.
Black Mask and White Mask
The Black Mask and White Mask buttons, located below the Backing Color button, cause PhotoFusion to automatically change the default control values in the Matte menu. For example, re-sample the Mask in an area you wish to be totally opaque to the new BG. Typically a dark gray area of the Mask that you want to convert to pure black. Pressing the Black Mask button will adjust the value of the Matte Density and/or the Black Gloss controls. No change will occur in the Mask itself until you press the ﾒPreview Allﾓ or ﾒPreview Selectionﾓ button. In this case, the light values of the Mask will remain relatively unchanged. However, the dark values will become more opaque, further obscuring the new BG in these parts of the final composition.
The White Mask button solves problems of an opposite nature. Perhaps there are defects on the backing color, like seams in the backing material, scuff marks, or simply uneven lighting that shows up in the Mask. These elements, if not corrected, will be interpreted by PhotoFusion as valid content and thus transferred to the BG of the new composite. Sampling a portion of the Mask with one of these defects, then pressing the White Mask button, will cause PhotoFusion to increase the Cleanup control, converting these low level grays to white, or near white in the Mask. Think of Cleanup as a threshold control for the Mask. The higher the value, the darker the Mask value must be before PhotoFusion will allow it to influence the final image. The use of the Clean-up control or the White Mask function will typically result in some loss of FG detail. Shadows will become thinner, as will smoke and reflections on glass.
You are not limited to only those Matte values PhotoFusion computes from the Black and White Mask buttons. You can make manual changes to any of the Matte control values, and preview these changes in the viewing area. You are free to experiment with any of the values, in any of the control menus, and then apply them to the image. Each has a specific purpose, and affects the final composite in a specific way.
Some of these control changes do not come without compromise. You can increase the Matte Density, for example, in order to darken parts of the Mask that would otherwise allow the BG to print through, but not without sacrificing the quality of some edges that may be darkened. Ultimately, the nature of the FG content will determine how far you can go with the controls before you compromise the final results. It is a worthwhile experiment to see the results of different Matte Density settings on the Mask---and final composite too. Increasing the Matte Density up from zero value, just to the point where the Mask captures fine detail and subtle components of the FG image, is the theoretical optimum setting.
PhotoFusion attempts to reach this condition when it creates the Mask from the initial sample of the backing color. You begin the process of refining automated decisions by increasing or decreasing the control values from their nominal setting.
Input/Output Files
PhotoFusion enables you to save your work midstream and return to Photoshop where you will have the opportunity to retouch the Mask and/or FG component of the image. You have the option to either finish the composite from within Photoshop or return to PhotoFusion to combine the images. You can use Photoshop to do the final composite but the patented technique of PhotoFusion eliminates the typical ﾒglowﾓ around the FG subject you often get with Photoshop.
PhotoFusion saves, and loads, four different types of file:
The first choice is the most obvious one. You load a FG image into PhotoFusion that is shot against either a Blue, Green or Red backing color. Next load the BG image into PhotoFusion. Click on the View Foreground button, and sample the backing color (creating a Mask). To view the composited image, click on the View Composite button. Clicking the Save button returns you to the Photoshop application with a new four channel image ready to save in your choice of file format.
The second choice in the Save Window saves an image, and exits PhotoFusion with an image called ﾒProcessed Foreground.ﾓ Processed Foreground refers to an image that is the same as the original FG but with the backing color suppressed to black and the FG subject ﾒde-flared.ﾓ It includes the fourth channel mask created by PhotoFusion---as is the case with all the PhotoFusion results, except the Control File.
The third choice for saving your work is called ﾒForeground & Mask.ﾓ This choice returns the same FG image you started with to Photoshop, with the same backing color, but with the addition of a Mask. The original FG image has not been subjected to any changes.
The fourth file saving choice is called the Control File. This is a special file format saved by PhotoFusion that contains a record, in ASCII format, of the all the Control values set by PhotoFusion and a record of how the Mask was generated. You are required to save and recall this file if you plan to exit PhotoFusion and return to it again with the same image to complete the process. PhotoFusion does not look for any kind of historical match between the Control File and the FG image. It is the userﾕs responsibility to load the proper Processed Foreground and matching Control File.
You normally save the Processed Foreground if you plan to interrupt the PhotoFusion process midstream. To further enhance this image, re-enter PhotoFusion selecting the ﾒProcessed Foregroundﾓ option in the Load window.
PhotoFusion is a resolution independent process. However, it only works with a ﾒsampleﾓ of the FG, BG and Mask image in the viewing area. You cannot assess the full impact of the results you will get until you actually view the saved file in Photoshop. The Viewing area reduces the time it takes to preview your work and the creative decisions you make. However, it still takes a finite amount of time to display these results.
To help speed the process, PhotoFusion allows you to apply certain controls to a portion of the image in the viewing area instead of having to wait for the entire viewing area to update.
The ordinary click-and-drag box draws a box (or multiple boxes) outlined in yellow in the viewing area. Holding down the Apple Command-Key while you click-and-drag creates a sample box outlined in purple. A purple box in the viewing area is used to confine the PhotoFusion process, or control adjustment, to this one specific section of the viewing area. This is particularly useful for focusing your attention on specific areas of the image where specific controls may apply. PhotoFusion limits its preview display in the viewing area to the confines of this purple box by selecting the ﾒPreview Selectionﾓ button instead of the ﾒPreview Allﾓ button.
Unlike the multiple click-and-drag of an ordinary sample box, you can only have one preview selection box in the viewing area at a time. Each click-and-drag, while holding down the Command-Key, will clear the previous box to create a new one. The ﾒFlush Pointsﾓ button only clears ordinary sampled boxes from the viewing area. Remove the selection box from the viewing area by un-checking the ﾒEnabledﾓ box in the Options menu, or by pressing the ﾒpﾓ key on the keyboard.
Color Controls
The PhotoFusion process goes beyond the task of stripping away the backing color from the FG and replacing it with a new BG. A truly realistic composite must deal with the possibility that the color balance of the FG and new BG may not be matched. PhotoFusion is equipped with a host of controls to make color matching changes to either the FG image, BG image or both.
There are seven major groups of controls to select from (plus an ﾒoptionsﾓ menu) in the upper left hand corner pull down menu group. Each group of controls starts out with preset values. We briefly explored the application of one of these sets of controls when we made changes to the Matte controls by using the Black Mask and White Mask buttons.
As a group, the Level, Black, Gamma and Saturation items contain parameters that offer control of these values for both the FG and BG image. As an example, the Level control can change individual RGB levels in both the FG and BG image. You can see the results of any changes to these controls by selecting ﾒCompositeﾓ in the viewing menu and pressing the ﾒPreview Allﾓ or ﾒPreview Selectionﾓ button after each change in value.
Color Conformance
PhotoFusion offers you the capability to make the matching adjustments to the FG and BG image by manually adjusting the controls in the Level, Black, Gamma and Saturation menus.
Of course it takes a certain degree of skill to determine which control(s) to change in order to accomplish the desired results. Alternatively, PhotoFusion has the capability to automatically compute the control changes required to make the images match. The process is called Color Conformance.
Using automatic color conformance requires that you select the desired control menu (Level, Black or Gamma) sample the composite image in FG and BG locations that are appropriate for the menu you are in, press either the ﾒFG to BGﾓ or ﾓ BG to FGﾓ button to affect the matching change to the controls values, then press ﾒPreview Allﾓ or ﾒPreview Selectionﾓ to see the results of the change in the composite image.
If you select ﾒFG to BGﾓyou will note that the BG RGB Level controls remain unchanged while the FG takes on new values. Similarly, you can cause the FG and BG ﾒBlacksﾓ to match by selecting the Black menu and pressing either one of the FG to BG or BG to FG buttons, followed by the ﾒPreview Allﾓ or ﾒPreview Selectionﾓ button.
The Color Conformance process responds to the ﾒFG to BGﾓ and ﾒBG to FGﾓ buttons on a menu by menu basis. For example, selecting the Gamma menu limits the process to the controls in Gamma menu only.
Automatic color conformance works with the Level, Black, and Gamma menus only. You must make changes to the FG and BG Saturation manually.
You may sample unlimited portions of the FG and BG image when using the automatic Color Conformance technique. Consistent with its sampling methods, PhotoFusion averages the pixel values within the total sampled area. The sampling process does not require the same number of samples in the FG and BG. You may sample in any order you wish and accumulate as many samples as you wish. Based on information it derives from the Mask, PhotoFusion knows whether a particular sample should be analyzed as belonging to the FG or BG.
The experienced PhotoFusion user additionally may manually refine the control values computed by the automatic Color Conformance mode.
You have been taken through the basic working functions of PhotoFusion. The caliber of the final composite is a combination of careful shooting conditions and lighting and an understanding of what sample information PhotoFusion needs to perfect the combined image.
The experienced PhotoFusion user knows how and when to take advantage of the vast array of image processing tools available in Photoshop to perfect the Mask. In general, you will realize your best results if you use PhotoFusion near or at its default settings and use Photoshop to refine the critical Mask image.
