Artsnova Digital Art and Space

Earthrise Over the Moon

Yesterday I finished up my part in the judging of entries in the NASA Life and Work on the Moon student art contest. The theme of the contest was portrayals of people living and working on the Moon. There were some interesting submissions to the contest. There were a few submissions that ignored the fact that this was an “art” contest and instead submitted presentations, pamphlets, etc. While these were outside the bounds of the contest, it was a pleasure to read through these and learn about what these persons considered to be the benefits of humans living on the Moon. For more contest details, visit the NASA art contest site The Moon: Back to the Future.

We judges were to grade the artist’s submissions based on four different criteria: artist statement; artistic elements; creativity; validity. Scoring was 20 points for the artist statement, 30 points for artistic elements, 30 points for creativity, and 20 points for validity.

Artist Statement

The artist statement was a written explanation of the submitteed art. Unfortunately some artists failed to provide a statement. I’m not sure why someone would spend a substantial amount of time creating an artwork to submit to the contest and then not take the comparatively small amount of time to explain the nature of their submission. The artist statements spanned a wide gamut from simple explanations of the image to complex explanations of the artist’s thinking and planning process.

Artistic Elements

Judging the artistic elements involved evaluating the artist’s use of line, shape, color, texture, etc. For me this represented the most difficult component to judge because such components are highly dependent on the observer’s values.

Creativity

Being creative while adhering to the contest’s rules for validity can be a challenge. One of the more creative submissions was an art deco style advertisement for tangtini - a drink composed of Tang and vodka. Unfortunately the connection between the piece and theme of living and working on the Moon was rather tenuous.

Validity

As the theme of the contest was living and working on the Moon, the submitted artwork was expected to be realistic in its depiction of the nature of the lunar environment and what living there would be like. Artists had to balance being creative while staying within the bounds of reality. Judging the validity of some submitted art was challenging in this category. For example, there was a very nicely done terraformed moon. But just how valid is that? Unfortunately that piece did not depict any human presence on the Moon.

I must say I enjoyed the experience of being a judge in the contest. The last contest I had an opportunity to judge was the NSS Space Settlement Art Contest which ended in January. Every artist should take a crack at being a judge in an art contest. It is one thing to look at a picture and say “Oh I like that” and quite another thing to analyze the picture’s composition and artistic elements with the goal of assigning a grade to the picture. The process can be very instructive.

About Earthrise Over the Moon

I created Earthrise Over Moon to illustrate this blog entry. As a source I used one of the HDTV images from the JAXA Selene (aka Kaguya) mission to the Moon. I then brought the picture into Adobe Photoshop and used the “Find Edges” filter to create an outline map of the areas of contrast change in the source image. I then used several custom brushes of my own creation to digitally paint the picture. For my Photoshop brushes, I used custom brush tip shapes and activated the Shape Dynamics, Scattering, Texture, and Color Dynamics options. These brush controls were set to be sensitive to pen pressure as I was using a Wacom stylus to paint the picture.

Ad Astra, Jim

Photoshop FITS Liberator screen shot

A new version of the free ESA/ESO/NASA FITS Liberator plugin for Photoshop was released earlier this month. This plugin makes it possible to open FITS files with Photoshop. For you Photoshop users who are not familiar with FITS, the Flexible Image Transport System is the standard file format for astronomical data, like that of the Hubble Space Telescope for example. For more FITS information visit my Making Astronomical Art with your PC Resources page which I created for students in the astronomical art class I taught at the Adler Planetarium.

According to the release notes, the following enhancements are in this new release:

1. Universal Binary for Mac allows native CS3 operation on Intel-based systems
2. Flip image checkbox allows image orientation to be selected on import
3. Stretch Root functions now operate antisymmetrically about x=0
4. Version 1.1 of the Astronomy Visualization Metadata (AVM) standard is fully supported. For more information see http://www.virtualastronomy.org
5. Improvements to importing coordinate metadata from the FITS header

I went to the version 2.2 download page and downloaded this new version. There is also a Photoshop action called Colour_composite.atn that can be downloaded. This action automates the production of color images from the individual RGB grayscale layers. I’ve never used their action preferring to use one I created myself. I installed the plugin without difficulty. On opening a FITS file (M27 for the curious among you) I observed that the main dialog for this new version was essentially the same with the only modifications being to the Stretch Function dialog (item 3 in the list above) and the addition of a Flip Image option (item 2 in the list above).

You can learn more about the plug-in, how to use, and even get some sample FITS files from the ESA/ESO/NASA Photoshop FITS Liberator Home Page.

Ad Astra, Jim

Figure 1. Viking 1 Lander color view of the martian surface.
Left: Mars as NASA shows it.
Right: Mars as Hoagland and company believe it to be using Photoshop Auto Levels.

The followers of Hoagland are at it again. They are still claiming that NASA is faking the colors of Mars - giving it a reddish sky when, according to them, the martian sky is really blue.

Quoting from their article posted 01/17/2008: “NASA has deliberately altered the colors of the images to make the Martian sky appear an absurd “Technicolor red,” when in fact all the evidence clearly shows that the true color of the Martian sky is (and must be) blue - just as it is here on Earth. In fact, when we used a simple color correction tool in Photoshop called the Auto Levels tool, Mars came out looking as Carl Sagan described it after the first Viking images in 1976 - it looked like Arizona.” Note that I am not including a link to the web site as the last thing I want to do is boost their standings in the search engines.

To illustrate what they are talking about, I went to the NASA JPL Photojournal web site and downloaded the same Viking image shown in conjunction with their story - see Figure 1 above. In Photoshop I duplicated the background layer and applied the Auto Levels command to that layer. I then cropped and downsized the image for display here. The left half of Figure 1 is Mars as shown on the NASA JPL web site. The right half has had Photoshop’s auto levels applied - resulting in a lovely blue sky. But is that really what the Martian sky looks like? Hoagland and his followers would have you believe that NASA, JPL (which is staffed and managed by the California Institute of Technology) and planetary scientists around the world are all part of a vast conspiracy that does not want us to know that the martian sky is blue. And since I am here to debunk Hoagland and company’s claims, I too must be part of that conspiracy. Cool! I’ve never been part of a conspiracy before - other than that age old parental conspiracy to convince their children that there really is a Santa Claus.

What about their claim that Auto Levels is a color correction tool? From the Photoshop Help description of the Auto Levels command: “The Auto Levels command automatically adjusts the black point and white point in an image. This clips a portion of the shadows and highlights in each channel and maps the lightest and darkest pixels in each color channel to pure white (level 255) and pure black (level 0). The intermediate pixel values are redistributed proportionately. As a result, using Auto Levels increases the contrast in an image because the pixel values are expanded (as opposed to being compressed, as in lower contrast images). Because Auto Levels adjusts each color channel individually, it may remove color or introduce color casts. Auto Levels gives good results in certain images with an average distribution of pixel values that need a simple increase in contrast.“

So Auto Levels is not a color correction tool but a contrast enhancement tool that in certain situations may introduce a color cast. Note the qualifications that Auto Levels can give good results in some images and that the quality of those results is purely dependent on the distribution of pixel values. Pixel values is a reference to the luminance of a pixel - how dark or bright it is.

Back to Photoshop, lets review one more time what Auto Levels does. For each of the color channels - red, green, blue - Auto Levels takes the lightest pixel value in the channel and remaps it to white, takes the darkest pixel value and remaps it to black, and then stretches out everything in between. Now the consequence of this is that the brightest red, green, and blue pixels will now combine to form white because they have all been arbitrarily set to a value of 255.

Figure 2. Digital photograph of an Arizona sunset

Let’s take a planet Earth example. Figure 2 is a photograph of an Arizona sunset that I took. On the left is the unmodified half of the photograph and on the right is the half as altered by the Auto Levels command. Why the large difference?

Figure 3. The Photoshop histograms for the blue channel of the Arizona sunset: before and after application of the Auto Levels command.

The histogram in figure 3 reveals what happened to the image. The histogram shows the distribution of luminance values for the blue channel before and after the application of Auto Levels. As you can see Auto Levels has significantly altered the distribution of luminance in the blue channel.

Now the question is which of these two images is a more accurate reflection of reality? Since I was there taking the photograph this is an easy question to answer. Auto Levels has both lightened the image and introduced a significant blue color cast and is not an accurate reflection of the sunset that I personally witnessed.

In closing, the claim that NASA, and the rest of the planetary science community, are lying about the true color of Mars and that the Photoshop Auto Levels command provides supporting evidence is baseless and without merit.

Ad Astra, Jim

Mars Global Surveyor Image:
Spring Thaw in Northwestern Planum Australe

Saturday I taught the first of a two part four hour class on astronomical image processing at the Adler Planetarium. The class, No Telescope, No Camera? No Problem: Making Astronomical Art with Your PC covers locating and downloading planetary and astronomical image data from the Internet and then using various image processing techniques to create finished pictures.

The first session covered both the basics of image processing and manipulation with Adobe Photoshop and how to use these techniques to transform raw PDS (Planetary Data System) image files into attractive colorized pictures. An added bonus was that these techniques are also applicable to the processing of images produced by digital cameras. The class consisted of both a lecture component and a demonstration component. Images used during the class were all downloaded from NASA JPL PDS Missions site.

For the demonstration component of the class, I demonstrated the following techniques:

• contrast enhancement and colorization of a single Viking Lander image of the Martian surface
• combining separate red, green, and blue Viking Lander images in order to produce a color picture while employing the contrast manipulation techniques previously illustrated
• combining red and blue filter images from the Mars Global Surveyor Wide Angle Camera and synthesizing a green channel to create a color picture
• using a Galileo image of asteroid Gaspra to explain enlarging and sharpening.

For some of the techniques, I showed that there was more than one way to get the job done and that the choice of methods really depended on the picture that was being worked. There was a lot of ground to cover and the class ran longer than its scheduled two hours. In addition to using Photoshop, I used both GIMP (with the PDS plug-in) and NASAView software to demonstrate how to open PDS image files and save them in standard graphics formats.

One of the exercises was to create a color picture of Mars by combining the image data from two Mars Global Surveyor Wide Angle Camera images: one taken using the blue filter, the other using the red filter. A small section of that picture is shown above. For purposes of comparison, you can compare this image with the Spring Thaw in Northwestern Planum Australe version posted on the Malin Space Science Systems web site.

Part two of the class will be held this Saturday and will cover the processing of astronomical images stored in the FITS (Flexible Image Transport System) format. For a list of this and other classes currently available from the Adler Planetarium, visit their classes page.

There are times when I have my laptop disconnected from the network and I want to do some serious graphics work. Because graphics software is very CPU intensive, I want my graphics program to have as little CPU competition as possible. This is especially true when I am working on very large images in Photoshop or running a render using one of my 3D applications, be it Lightwave, Mojoworld, or Bryce.

Now I could use the Windows Task Manager to go in and one by one shut down processes that I know aren’t needed. Or I could use the Windows XP System Services tool services.msc to accomplish the same thing.

There are a few problems with this approach. First I need to remember what processes to shut down each time. Being disconnected from the network allows me to shut down quite a few additional processes like antivirus, firewall, and other internet-related processes. On a typical Windows PC, this can be a rather lengthy list. And once I know what I want to shut down, I have to find each process in the list of processes and manually shut them down one by one. What a pain.

My solution was to automate the process. I had previously created a directory on my laptop called a_Utils which contained a variety of DOS batch programs I had written. One thing I did when I created this directory was to make sure that it was in the Windows Path environment variable - a variable that tells Windows where to look for programs. This variable can be set on Windows XP as follows:

1. Right click the My Computer icon and select Properties
2. Click on the tab labeled Advanced
3. Click on the Environment Variables button
4. In the System variables window, locate the variable Path and select it by clicking it once.
5. With Path selected, click on the Edit button at the bottom of the window.
6. In the Variable value field, go to the end of the field, add a semicolon if one is not already there and type in the full path to the directory that contains your batch file.
7. Click the trail of OK buttons back to the System Properties window
8. Click the OK button

In my directory a_Utils I created a DOS batch program file named !KillTasks.bat. This file consists of a list of taskkill commands. Taskkill is a Windows command line program that is used to terminate one or more tasks or processes which are identified by either their process ID or image name. I use the command in the following form:

taskkill /f /im ImageName

The parameters I specify are:

• /f which tells Windows to “forcefully” terminate the process. In other words, don’t take no for an answer.
• /im tells Taskkill that I am specifying the image name of the process to be terminated.
• ImageName gives Taskkill the name of the process to terminate.

So far this has all been rather straight forward. Now the trick is in identifying what tasks or processes you can safely terminate. My method of doing this was to open Windows Task Manager and go to the Processes tab. Looking over the list of processes, the function of several was obvious and I knew whether or not it was a process that must run or a process I could kill. For others, I plugged the Image Name into a Google search in order to determine what the process does and whether or not I could kill it.

Following is an extract of what my !KillTasks.bat looks like. In this extract I am only including the commands for terminating my Nikon camera monitor and Copernic desktop search tool. The actual list is much longer.

I close my program with the PAUSE command. This prevents the DOS window from closing until I press the Enter key, giving me the opportunity to look over the command output. This is just a personal preference on my part.

Now whenever I want to disconnect from the network and do some serious graphics work all I have to do is run my batch program. To make it really easy I created a shortcut to the program on my desktop. One double-click and my laptop is ready for some heavy duty graphics work.

Ad Astra, Jim

A lot of the images that I work on in Photoshop are big. Really big. And no, I’m not digitally manipulating pictures of Paris Hilton, though that is an interesting thought. I can see her sporting a stylish goatee and mustache. Now when I say big, I generally am addressing pictures whose smallest dimension is larger than 3000 pixels.

As it happens I frequently want to experiment with the Photshop filter set to see what impact different filters have on the image. It is especially interesting to see the results of combined filter effects. The problem is that even with a fast PC with loads of memory, Photoshop will take some time to process the complete image and I am just to impatient to wait.

My solution is as follows. First, I identify a section of my original image which is not only representative of the entire image but includes part of the image area for which I am most interested in seeing the filter’s effects. I try to keep the dimensions of this area to that of my screen at 100% resolution - so we’re talking approximately 1400 by 1000 pixels. Using the Rectangular Marquee tool, I then select that area of my image and Ctrl-C to copy it. Then Ctrl-N to open the new document dialog. Just click the OK button and then Ctrl-V to paste the selection into the new document. For the pictures that I work with, on average this new document represents about a 90 percent or more reduction in the number of pixels Photoshop has to work with.

I am now free to speedily experiment with different filters and different combinations of filters. Once I’ve figured out what I want to do, I then go back to the source image and apply the desired filter effects.

So next time you have a really big image and want to test out some filter effects, consider working with a only a portion of your image.

Ad Astra, Jim

Chicago Society for Space Studies web site.

Saturday I completed a total redesign of the Chicago Society for Space Studies web site - which in part explains why I haven’t been posting new entries here lately. And since I was in the process of doing the redesign, I took the opportunity to also write an article outlining the process. That article - A Web Site Redesign - appears on my Astrodigital web site.

The redesign I performed would not have been possible without the use of 2D graphics software. Of course my software of choice is Adobe Photoshop. While I have used Photoshop before to create buttons, logos, banner images, and web page elements, I had never used it to create a total graphic page design. That design, shown above, was actually quite easy to create.

For the banner image, I felt that a night view of the Chicago skyline would be most appropriate since it combines the elements of Chicago and space via the presence of the night sky. The Chicago skyline is a composite of two photographs taken at night from the site of Chicago’s Adler Planetarium. To capture the two images, I set my camera up on one of my tripod’s and shot in manual mode, which allowed me to control ISO, speed, and aperture. I also created a new version of the CSSS logo that fit in better with the banner image color wise.

The most time consuming part of the design process was not the actual creation of the design, but rather coming up with the mental image of the type of design I wanted to create. I was guided in this process by looking through free web site template sites. There is more on that in the A Web Site Redesign article.

Realization of the site graphic/design was accomplished by creating a multi-layered Photoshop document. I started by creating a solid background, the color for which I was sure to note as I would use this color to define the web page’s background color in the CSS (Cascading Style Sheet) file. This was layer one. On layer two I made a rectangular selection of an area of the same size as the page area, feathered the selection, and filled it with a dark gray: this would serve as the shadow area around the page content area. Back to the rectangular marquee, on layer three I selected a rectangle and filled it with white: this would serve as the content area background. On layer four I added the Chicago skyline image. I placed the CSSS logo on layer five. By putting the logo on its own layer, I was free to experiment with positioning the logo and while keeping my options open for any future changes. Next up the layer ladder, on layer six I created a rectangular selection and filled it with gray: this would be the area used to hold the horizontal navigation bar. Layer seven was used to create the frame that serves as the page border. The frame around the page was made by simply creating a rectangular selection, feathering the selection, converting the selection to a border selection, and then stroking the path. I then used a layer style to give the border a 3D effect.

It was all pretty simple actually. The final step was to switch to ImageReady and slice up the image into the appropriate components. It was then necessary to create the CSS that would reassemble the individual graphic components while allowing for content control within each of those individual areas.

Once I had my CSS and XHTML template created, it was just a matter of replacing the old page layout code with the new code. Not mentally challenging but tedious. The worst part of the whole process was validating all the HTML associated with the content as I had decided to change from coding using an HTML doctype to an XHTML doctype.

If you want to take a closer look at the design, and learn a little bit about space in the process, I encourage you to visit the Chicago Society for Space Studies web site.

Ad Astra, Jim

Mars Reconnaissance Orbiter Image of Polar Layers

At long last instrument data files from the Mars Reconnaissance Orbiter have been added to the NASA PDS Imaging Node web site. Present is data from the High Resolution Imaging Science Experiment (HiRISE), Context Camera (CTX), and Mars Color Imager (MARCI). While the Context Camera has returned some great imagery, it is entirely overshadowed by the pictures captured by the High Resolution Imaging Science Experiment. Most impressive was a HiRISE image that showed not only the Mars Exploration Rover Opportunity but the shadow from the PanCam mast. This picture can be seen on the Victoria Crater at Meridiani Planum TRA_000873_1780 page.

For those not familiar with the NASA PDS Imaging Node, this is the place to go to obtain the raw data files for various instruments from a variety of NASA planetary missions. Quoting from the news release about the addition of MRO data, “a PDS data node is designed to provide access to a particular data set during an active mission, when the data are of greatest interest” The Data Holdings Catalog page provides a full index to the data resources available. Note that as of this writing, the Mars Reconnaissance Orbiter data has not been added to the list. However, you can bypass the PDS home page and go directly to the Mars Reconnaissance Orbiter Online Data Volumes.

The image used to illustrate this entry (see above) is a 100 percent resolution subsection of a Context Camera image. To process the image I used Adobe Photoshop. I began by doing a dual High Pass Filter effect to sharpen the image. I then colorized the image using both a color layer and a Hue Saturation Adjustment layer, applying the two in tandem. The final step was to add a Curves Adjustment layer to increase contrast in the picture.

Some Useful Mar Reconnaissance Orbiter Links

• NASA’s Planetary Data System (PDS)
• Mars Reconnaissance Orbiter web site
• MRO HiRISE camera web site
• MRO HiRISE image search tool

Ad Astra, Jim

Which Flag Do You Prefer? Before and After Using Serif PanoramaPlus 1

I was in a local bookstore last week going through the magazine section and pulled the current issue of the astronomy magazine BBC Sky at Night. I’m in the habit of going through all the astronomy magazines in search of interesting articles. Unfortunately for Sky at Night I’ve never came across an article in their magazine that would make it worth its price. Looking at the May 2007 issue, it wasn’t what was inside the magazine that grabbed my interest but what was on the CD that comes with the magazine.

The CD has a full version of Serif’s PanoramaPlus, version 1. This program automates the creation of panoramic images given a list of individual source images. Previously I had created my panoramas by using Adobe Photoshop’s Transform Tool and layer masks. Needless to say the Transform Tool is definitely suboptimal - especially when it comes to altering the geometry of the individual images. While I wasn’t thrilled that as a part of the software activation process I had to call the UK offices of Sky at Night, I figured that would be cheaper than going out and buying the software. What bugged me about this is that for all other magazines containing CDs with full versions of software being offered, I’ve never had to make a phone call to activate the product: either it was ready to go or all I had to do was point my browser at the specified web page to complete the registration.

Fortunately the software did have a one time use without registering so that I could fire it up and test it out. I fed the program a total of 11 images from an Apollo 16 EVA to merge. Their combined file size was 8.5 megabytes. PanoramaPlus quickly stitched them together and as far as I could tell from the software’s preview window, had done a good job of it.

The final step was to export the newly created panorama. Therein lies the source of my disappointment. The only export format available was to save as a jpeg. Not only that but there was no option to specify image quality and no documentation identifying what compression setting the software was using. The other shock was the size of my new panorama - just 3000 pixels wide. PanoramaPlus had taken 11 separate images with a combined width of 25,740 pixels and combined file size of 8.57 megabytes and created a panorama just 3000 pixels wide with a file size of 880K.

As a before and after comparison I took the American flag from the panorama and enlarged it to match the flag in one of the source images. The comparison of the two flags is shown at the top of this article. Note that the image shown is a scaled down version of the full size comparison. On the left is the original source flag image and on the right is the flag image from the PanoramaPlus panorama, upsized to match the size of the original flag. The qualitative difference is obvious.

Going to the Serif web site, I see that they are now on version 3 of the software so it is probably no longer the same product. Bottom line: if you’re thinking of buying the May 2007 issue of Sky at Night because of the PanoramaPlus version 1 software, don’t - big mistake. And the special upgrade offer they are running in the magazine: if you’re in the U.S. and paying in U.S. dollars, the standard price for the software is cheaper than the Sky at Night special “discount.”
Ad Astra, Jim

Photoshop National Space Society Banner Let’s Build a Future Together by Jim Plaxco

Last night I submitted an entry to the NSS (National Space Society) Banner Design Contest. What made my submission unusual is that I am one of the judges for the contest. This left my fellow judges wondering what my intentions were - was I dropping out as a judge to become a contestant? Did I want a crack at the $500.00 cash prize? Not at all I explained. The night before (Wednesday) I had gone to the NSS Banner Design Gallery to look over the submissions that I would be voting on. Unfortunately I didn’t see any that I really liked. Most were far too science fictiony for my tastes given that these designs are to be used to produce a banner promoting the NSS and its chapters. I expressed my negative feelings to my fellow judges in an e-mail. After sending that e-mail, I thought “why just criticize - what can I come up with?” I figured that I would see what I could do so later that night I set out to create my own banner design. It is that design which is the illustration for this post. You can see a larger version on my submission page.

In creating this banner, there were five basic elements to consider:

• the background image
• the NSS logo
• the NSS name
• an appropriate slogan
• creating a composition from these individual elements

For a background, I decided to go with a lunar landscape that featured an Apollo LEM (Lunar Excursion Module). To achieve this, I composited together a series of Apollo 16 70mm Hasselblad images. These became a single layer in my Photoshop document. I located a separate image of the Earth, also from the Apollo 16 mission, taken en route to the Moon. I brought this into Photoshop as another layer. To this I added a Hue/Saturation adjustment layer as a clipping mask and slightly increased both the saturation and lightness of the Earth.

I now had to come up with a slogan. A page full of scribbled ideas later, I decided to go with “Let’s Build a Future Together.”

Lastly, with the Moon, the Earth, my slogan, the NSS logo, and the NSS name all on separate Photoshop layers, I began to work with both the placement and the sizing of the individual elements. At this point the only element that remained static was the lunar background. I eventually arrived at a composition that I was happy with and called it a night.

Yesterday after work I used the automated design submission form to enter my design in the contest. Why not give it a try yourself. You can find all the details about the contest at the National Space Society Banner Design Contest web page.

Ad Astra, Jim