Run DStretch from the web using an ImageJ Applet.

An applet is a neat way to run a program from your web browser.

Be patient!  The applet version of ImageJ should open in a separate "ImageJ" window. With a slow connection, this may take a minute or two. When it is loaded a popup should appear asking if you trust this applet.   I have "signed" the ImageJ applet.  If you accept the certificate you can use DStretch on your own files!  If not you can use the sample images (File->Open Samples).  The applet works with the latest versions of Internet Explorer,  Firefox and Opera.

Quit ImageJ by clicking on the "ImageJ" window's close button.

Note that ImageJ may require an updated browser or Java platform  If you have a PC or Linux you can get the latest Java platform from here.  Sun is changing the Java site faster than I can keep up, hope you can find the latest JRE.

ImageJ and DStretch will work like an application on your computer.  You can open and save your own files. 

Java limits applet memory which will limit the size of files you can open and enhance.  If you can't open images or enhancement mysteriously does nothing suspect memory problems.  You set the applet memory limit by entering something like "-Xmx200m" in the Java Plug-in's "Java Applet Runtime Settings" field.  Here 200 is the amount of memory (in megabytes) allocated to applets.  Change this number according to your computer's resources.  On Mac OS X,  the Java Plugin is in Applications/Utilities. On Windows, it is in Control Panel->Java Control Panel->Java->Java Applet Runtime Settings.  Note: the applet memory limit is separate from the ImageJ application memory limit.  If running ImageJ as an application use the "ImageJ->Edit->Options->Memory and Threads" menu item to change memory.

If you can at least load one image then another way to deal with memory problems is to reduce the image size using Image->Scale (Choose the defaults).   After scaling delete the original and then run DStretch on the scaled version.

Once ImageJ opens then choose a file to open.  You can access some of my pictograph images by using the file->”open samples” menu.

There are several images to choose from.  Including all the images from the examples.  It may take a little while to open.

After you have loaded an image then open DStretch using the plugins->”DStretch...Run” menu item.

08-16-2007:  I have added a Kachina Rockshelter image from my ARARA presentation to the samples.  Red enhancements work well on it.  Try CRGB, LRE or the Y Red Enhance values for YXX.   YBK and L Black Enhance help make some charcoal scratches more visible.

I have found the new color balance routine to be useful when the background rock is reddish.  Use it before or after doing a stretch,
Use the Sat button to tame the wild colors you can sometimes get after a stretch.

DStretch has user adjustable colorspaces, see below.  My experiments with this feature have produced several colorspaces that I think will be very useful.  I have made these available in the plugin menu.  They are LDS, LRE, YBK, YBR. Try out LDS on San Borjita 3174 or the Catavina cave image.  It often gives truer colors and less jpeg artifacts than YDS, but unfortunately is slower to calculate.  I think LRE will become an alternative to CRGB on red pigments.  It gives less wild colors, less jpeg artifacts,  but like LDS it is slower to calculate.  Try it on  the Catavina abstract image.  Try YBK on the famous "rooted man" from El Vallicito in Baja California near Mexicali.  Another interesting image is the lion from Santa Gertrudis Norte.  A very difficult image to enhance well, LAB BTN produces a beautiful result.  I have also included an image of a very beautiful human figure from Tulare County.  LRE or CRGB works well on this.

You can create your own colorspaces.  Use the YXX and LXX buttons.  The parameter values that I used to create LDS, LRE, YBK and YBR are shown there, but you can try your own.  I even have suggested coefficients for Y Red Enhance and L Black Enhance.  If you find a useful colorspace please let me know!

Original image from which the Stories on Stone logo was made.    This is image 8, the Green Anthro image.

Green Anthro Stories on Stone, the Rock Art of the Colorado Plateau at Museum of Northern Arizona in Flagstaff, 2005-2006.

The image was taken by David Sucec and enhanced by Bob Mark, Rupestrian Cyberservices

Bob used DStretch to get that remarkable image from the "Green Anthro" image, but I am not sure what settings he used.  To get nice enhancements that show the little sheep on the right use DStretch LDS or YBK.  Bob is the person who first suggested decorrelation stretch to me as a possible useful enhancement technique for rock art.  Thanks Bob!

For help in using DStretch look at the Examples or Help pages

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