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On this page: Description, Step by Step, Notes

Description

Export Images makes a copy of images associated with exhibits. This may be useful for people who want to switch their internal images to external images, or who are using external software such as my Second Site program, which only processes external images. Depending on the setting of the options, you can use this feature to:

Each of the options is described below, and then step-by-step instructions are provided for some common tasks.

Use the [Choose Folder...] button to set the output folder. Any updated images are stored in this folder.

For external images, the filename and filetype are set the same as the input file. For internal images, the filename is set based on the context and the filetype is set based on the image type. Second Site determines the image type by inspecting the image data. The context varies based on whether the image is attached to a person, an event, a source, etc.

Choose which images you want to process in the Exhibit Types pull-down menu. If you want to process internal images only, choose "Internal Images Only". If you want to process external images only, choose "External Images Only". If you want to process both internal and external images, choose "Internal and External Images".

Convert Internal to External is only enabled when Exhibit Types is set to "Internal Images Only". The Convert Internal to External option is useful, but also dangerous. When checked, the Export Images feature will copy the internal image data to a file in the output folder, then it will delete the internal image. For that reason, the Resize Image option is disabled when Convert Internal to External is enabled and checked.

When Convert Internal to External is checked the original image data is written to disk, with no resulting loss of image quality.

If Resize Image is enabled and checked, the Width and Height arguments are considered the maximum for the corresponding dimension and the size of the image will be increased or reduced to those maximums while maintaining the aspect ratio of the original image. The Width and Height arguments are in pixels.

Reduce Dimensions Only is enabled when Resize Image is enabled and checked. If it is checked, only images with at least one dimension larger than either the corresponding Width or Height argument will be resized. Said another way, with Reduce Dimensions Only checked, large images will be shrunk but small images will be unchanged.

Step by Step

Variations in this section:

Step by Step: Convert Internal Images to External

  1. Make a backup of your dataset!
  2. Choose Export Images from the function tree.
  3. Choose "Internal Images Only" from the Exhibit Types pull-down menu.
  4. If Convert Internal to External is unchecked, check it.
  5. Click the [Export Images] button.
  6. Review the log to see the filenames assigned to the images written to the output folder and to check for any error messages.
  7. In TMG, use the File > Maintenance > Optimize command to recover the space used by the internal images in the database files.

Step by Step: Make Resized Images for Second Site

  1. Choose Export Images from the function tree.
  2. Choose "External Images Only" from the Exhibit Types pull-down menu. (Second Site only processes external images)
  3. Convert Internal to External wil be disabled.
  4. If Resize Image is unchecked, check it.
  5. Under normal circumstances, you'll want to have Reduce Dimensions Only checked. There is usually no reason to expand the size of an image when it is published on a web site or CD-ROM, and quality suffers dramatically when you expand an image.
  6. Set the Width and Height parameters as desired. Generally speaking, it is important that pictures not be excessively wide, especially when integrated with a narrative. I suggest you choose a Width value in the range of 200 to 300 pixels. The Height parameter is less important. Choose a number about 100 pixels larger than the Width parameter.
  7. Click the [Export Images] button.
  8. Review the log to see the filenames assigned to the images written to the output folder and to check for any error messages.

Notes

  1. TMG Utility uses the PolyImage Image Processing Library from Polybytes® for some of the processing associated with exporting images.
  2. When resizing images, the Bits-per-Pixel (BPP) property of the image may change. For example, a 24 BPP grayscale image will be changed to 8 BPP during resizing. Conversely, if a color image is resized, the image library may change the BPP from 8 to 24 as a result of adding new colors to the image. Colors are added as a result of a "color averaging" algorithm which is part of the resize operation.
  3. When resizing images, the log includes the dimensions of the exported image. Unfortunately, that information is not available when Log Only is checked.
  4. TMG Utility may crash after you click the [Choose Folder...] button. If so, please enter the path to the desired folder in the textbox beneath the button.