There are a lot of options available in this plugin.  To configure it, you find a top-level Gallery menu in the admin menu.  The main page looks very similar to the WordPress Dashboard page.  The one thing that is missing is a link to the plugin page itself.

Before you do anything else, go to the Options sub-page.  From here you’ll notice a number of options pages for configuring different parts of the plugin, including General, Thumbnails, Images, Gallery, Effects, Watermark, and Slideshow.

General Options

• Gallery path
  Most people won’t have to change this.  I needed to because I share the same WordPress installation using a modification of MultiBlog by Stephen Rider, so the default location (wp-content/gallery/) would place the images for all sites using that installation in the same directory.
• Delete image files
  Check if you want to the image files to be deleted from the disk when you delete images from a gallery.  Disabled by default.
• Activate batch upload
  Allows you to specify multiple image files to upload in a single batch.  Requires Adobe Flash 9.  This provides a major improvement in the upload experience.  Disabled by default.
• Activate permalnks
  Check this if you want nice permalinks to be generated for galleries and images.  After checking this you have to regenerate permalinks.  Disabled by default.
  • If your WordPress site is hosted on IIS, you won’t be able to check this checkbox unless you’ve purchased a product that gives you the .htaccess features of Apache.
• Activate related images
  Check this to have the plugin generate a section at the end of posts for images whose tag matches the post’s tag or category (see the next option).  Pretty cool!  One problem I found is that the background behind the images is white which may not match your theme.  Disabled by default.
• Match with Categories or Tags
  Specifies whether you want an image’s tag to be matched against a post’s category or tag.  Defaults to Category.
• Max. number of images
  Specifies the maximum number of images to show with each post.  Specifying 0 will show all images.  This value defaults to 7.

Thumbnails

After making changes to thumbnail options, you will need to regenerate thumbnails in all galleries.

• Width x height (in pixels)
  Specifies the maximum width and height for thumbnail images.  The default is 100 x 70.  I like larger thumbnails so I specify 128 x 128.
• Set fixed dimensions
  Ignores the aspect ratio of images and generates a thumbnail to the exact dimensions specified above.  Disabled by default.
• Crop square thumbnail from image
  Creates square thumbnails.  The note on the page says to use only when the dimensions are set to 128 x 128.  I’m not sure what happens if the dimensions are set to something else.  Hopefully it fails gracefully.  Disabled by default.
• Thumbnail quality
  This is a percentage of maximum quality.  I haven’t played with this so I can’t comment on how it works.  Defaults to 100%.
• Resample mode
  Specify a value between 1 and 5, with higher values using more CPU.  I haven’t played with this so I can’t comment on how it works.  Defaults to 3.

Images

• Resize images
  Specifies the width and height that images will be resized to.  These are maximum dimensions and aspect ratio is maintained.  Images are only resized when you choose to do that specifically.  Images are not resized when you upload them.  Defaults to 800 x 600.
• Image quality
  This is a percentage of maximum quality.  I haven’t played with this so I can’t comment on how it works.  Defaults to 85%.
• Resample mode
  Specify a value between 1 and 5, with higher values using more CPU.  I haven’t played with this so I can’t comment on how it works.  Defaults to 4.
• Cache single pictures
  When using the singlepic tag, the image is resized for display on the page based on the values specified with the tag.  If this is checked, those images will be cached for each singlepic setting, which will improve load times and CPU loads on subsequent page loads.  I haven’t played with this so I can’t comment on how well it works.  Disabled by default.
• Clear cache folder
  Push button that allows you to clear the cache.

Gallery

• Activate jQuery navigation
  You should not check this box.  Alex’s advice to anyone who ever checked it is to disable it.  My advice to Alex is that if it shouldn’t be used, he should remove it before releasing each version.  Disabled by default.
• Deactivate gallery page link
  When enabled, clicking on a gallery (e.g. in an album) will cause the gallery to be displayed on the same page.  When disabled, the page you have associated with the gallery will be displayed.  Enabled by default.
  • I’ve made some changes to this behavior which I’ll describe later.
• Number of images per page
  Specifies how many images are displayed on a gallery page.  All images are displayed if 0 is specified.  Defaults to 0.
• Integrate slideshow
  Allows visitors to switch between viewing the thumbnails in the gallery and viewing the pictures as a slideshow.  You can also specify the text that is displayed to switch between the two modes.  Enabled by default.
• Show first (thumbnails, slideshow)
  Specifies what to view first when a gallery is displayed.  Defaults to Thumbnails.
• Show thumbnail description
  Specifies what to display under thumbnails in a gallery.  Defaults to None.
  • None - Just the thumbnail is displayed with no text.
  • Description text - The text entered in the description field for each image is displayed under the thumbnail.
  • Alt/Title text - The text entered in the alt/title text field for each image is displayed under the thumbnail.
• Show ImageBrowser
  If enabled, a larger version of the image will be displayed on the page when clicking on an image.  If not enabled, what looks like a pop-up window is displayed in the middle of the page to display the image and the page behind it goes dark.  I much prefer the non-ImageBrowser effect (disabled).  Disabled by default.
• Sort thumbnails
  Specifies how thumbnails are sorted when displayed in a gallery.  Defaults to Image ID.
  • Image ID - Sorts thumbnails by the ID of the image.  This works well if you import them in the order you want them displayed.
  • File name - Sorts thumbnails by the name of the image file.  This works well if your image files are named the way you want them sorted.
  • Alt/Title text - Sorts thumbnails by the alt/title text specified for each image.  This defaults to the name of the image file or to the EXIF data if you specified that during import, but you can change this at a later date.
• Sort direction
  Specifies the direction for sorting (ascending or descending).  Defaults to Ascending.

Effects

This page has a note about Thickbox being the only effect that is added to the theme.  I’m not sure what this actually means, it could mean that you have to install something before the other effects will actually work.  It would be handy if there was a pointer to the other effects on this page.

• JavaScript thumbnail effect
  Selects the effect to use when clicking on a thumbnail.  Choices include None, Thickbox, Lightbox, Highslide, Shutter, and Custom.  Although it’s not clear from the UI (because it’s always editable), it appears that selecting Custom allows you to modify the style used (in the Link code line box).  I’ve only tried Thickbox so I can’t comment on the others.  Defaults to Thickbox.
• Link code line
  Shows the code that will be used to display images when the visitor clicks on a thumbnail.  The text is always editable, but it may only be saved when Custom is selected for JavaScript thumbnail effect.
• Select loading image
  This option is only displayed when JavaScript thumbnail effect is set to Thickbox.  Two options are displayed - a series of dots in a circle and a horizontal bar that looks like a progress bar moving like a barber pole.  The latter is the default.

Watermark

These options allow you to add a watermark to images.  There’s a note at the top of this page saying that once a watermark is added it can’t be removed.  Watermarks are added from the Manager Gallery page.

You can choose to add either an image or text as a watermark.  There are several additional options if you select text, such as font, size, color, and opacity.

Slideshow

The options on this page configure how NextGEN Gallery displays slideshows using JW Image Rotator.  Alex provides a nice link to the options that can be set on the rotator (http://www.jeroenwijering.com/?item=JW_Image_Rotator).  I’ll summarize the options here as they appear on the Slideshow option page.

• Default size (W X H)
  Specifies the default size of the slideshow.  This is the size at which slideshows are displayed.  Defaults to 320 x 240.
• Shuffle mode
  If enabled images are displayed in a semi-random order.  Otherwise they are displayed in the order specified by the sorting options on the Gallery page.  Disabled by default.
• Show next image on click
  When enabled, causes the next image to be displayed when the current image is clicked.  Enabled by default.
• Show navigation bar
  When enabled, shows a bar about 1/5th of the way up from he bottom that displays the description in the middle and arrows on either side for navigating between pictures.  When using the default slideshow size, I found the navigation bar to be too distracting.  It might be more useful on larger slideshows.  Disabled by default.
• Show loading icon
  I didn’t see a difference whether this was enabled or disabled.
• Use watermark logo
  Uses the settings on the Watermark options page to add a watermark to each image in the slideshow.  I suspect it is only added to the scaled version being displayed, not the original version stored in the gallery.  Disabled by default.
• Stretch image
  Allows you to specify how images that have a different aspect ratio than the slideshow.  For example, this is useful for determining how portrait images should be displayed.  I found that no option had any effect whatsoever; portrait images were always stretched to fit the slideshow area.  Defaults to true.  From the JW Image Rotator page:
  • true - stretch images proportionally to fit the slideshow area.
  • false - stretch images to fit the slideshow area (I’m not sure how this differs from fit)
  • fit - stretch images disproportional to fit the slideshow area.
  • none - keep original dimensions.
• Duration time
  Specifies how many seconds each image should be displayed before moving on to the next one.  Defaults to 10 seconds.
• Transition / fade effect
  Specifies how to transition from one image to another.  Defaults to random.
  • fade - fades one image out as the new image fades in.
  • bgfade - fades to the background color and then fades to the new image.
  • slowfade - like fade only slower.
  • circles - displays rotating circles that grow larger to reveal the new image underneath.
  • bubbles - displays rising bubbles that grow larger to reveal the new image underneath.
  • blocks - displays blocks that move from one corner to the opposite corner to reveal the new image underneath.
  • fluids - like bubbles only from the center, as if liquid has been spilled on the image.
  • flash - quickly flashes to white and then fades the new image in.
  • lines - displays vertical lines that move left and right to reveal the new image underneath.
  • random - randomly selects a transition effect for each transition.
• Use slow zooming effect
  This enables a very cool effect that zooms into the images a little bit and then moves across them.  Disabled by default.
• Background color
  Specifies the color of the background for slideshows and for image popups.  Defaults to black (000000).
• Text/button color
  Specifies the color for text and buttons.  Defaults to white (FFFFFF).
• Rollover/active color
  Specifies the color of text and buttons when rolling over them.  Defaults to red (CC0000).
• Screen color
  Not really sure here as by default there is no numeric value.  It looks like it uses white, though.
• Background music (URL)
  A URL to a music file to play while the slideshow is playing.
• Try XHTML validation (with CDATA)
  I didn’t try this so I can’t comment on it.  There is a comment next to this option saying that it could cause problems with some browsers.