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Procedures for Capturing Herbarium Specimen
Digital Images

[I. Setup Prodecure]  [II. Image Manipulation Procedure]  [III. File naming Procedure]

NOTE:
This set of procedures is specific to the setup within the UNC Herbarium. The system includes the ProgRes 3012 High-Resolution Digital Camera mounted on a standard camera stand allowing for vertical movement.

The herbarium sheets are positioned within a custom-built shadow box, approximately 1.5 ft wide, two ft long and 1.5 feet high. During the picture sessions, the box is placed across the camera stand platform, with the long side facing out. The box is constructed of white styrofoam-filled poster paper, except for the two short sides, which are white translucent plastic. Two 500 watt halogen lights on tripods are positioned on either side of the box, exposing the box and its contents to the bright light throught the plastic sides. The result is that with the light reflecting off the four sides, there is absolutely no shadow created by the slight three-demensionality of the herbarium specimens, even including cones of several of the specimens.

The primary image manpulation tool is Photoshop from Adobe, including plugins from the vendor of the camera.

I. Setup Procedure

  1. Turn on computer.

  2. Turn on ProgRes 3012 Camera; green button in the upper right corner of the power box. Remove lens cap.

  3. Open Photoshop by double-clicking on the icon.

  4. Go to File/Import/ProgRes.

  5. Place specimen inside the shadowbox.

  6. Turn on both side lights. They should be positioned as close to the shadowbox as their stands will allow.

  7. Using the black knob on the side of the camera stand, adjust the camera height until specimen is fully visible on monitor. Make sure that the edges of the styrofoam pieces do not interfere with the image visibility.

  8. Place scaling device on the specimen.

  9. Click on "Start Focus."

  10. Adjust the focus on the main camera body using the outermost adjusting ring on the lens until the green bar on the right of the screen reaches its maximum height. Optionally, use the numerical counter to the right of the "Start Focus" button to achieve maximum focus; higher numbers equal better focus.

  11. Once highest focus is achieved, click on "Stop Focus."

  12. Adjust the aperture by rotating the innermost ring on the lens. Correct aperture setting achieved when nearly all of the red color has disappeared from the image on the monitor. It is o.k. to have a few points of red still pulsing on the image.

  13. Check the colour balance by clicking the "Balance" button on the bottom left of the screen. Make sure that all:
  14. Capture the image by clicking on "Capture" at the bottom right of the screen.

  15. While the camera is scanning, avoid disturbing the camera or specimen. Once the monitor reads "Assembling...." it is o.k. to turn off the lights and remove specimen from the shadowbox.

II. Image Manipulation Procedure

Steps in using Photoshop menus are annotated thusly:

[menu]>[menu selection]>[menu selection option] (ok)


This indicates a particular menu and the subsequent selections within the menu and sub-menus, finally followed by clicking the appropriate 'OK' box after completing the selections.

  1. Scan image at (second best) resolution (18 mb) - see above procedure.
  2. Create web-accessible image file
  3. Create web-accessible label and annotations file

Additional manipulations used for the BOTNET project are described below.

Cropping:   At the very top left of the vertical tool bar, click on the Marquee Tool (hashed box). Click at a corner of the image and expand the hashed box until it surrounds the image with the portions to be cropped left outside the hashed box. Pull down the "Image" menu and click on the "Crop" selection. After the process is complete, the cropped portion will disappear.

Rotating image:   In the "Image" menu, click on "Rotate Canvas," and choose the desired direction and degree of rotation.

Adjusting levels:   This is a manipulation that will give a much clearer image. Go to "Image" and click "Adjust", then "Levels." A 'levels' screen will appear on the monitor that includes a graph of the image data. Using the left mouse button, drag the black arrow to the right until it is positioned just below the point where the data/graph appears. Do the same with the open/white arrow, but, instead, drag this one to the left, and usually not as far. Once adjusted, click "OK."

Sharpening image:   Go to "Filter," "Sharpen," and click "Unsharp Mask." The default settings are fine. Click "OK." It is sometimes best to do the Unsharp mask treatment twice for each image, but it will depend on the image.

III. File naming Procedure

Each file will have at most four sections:

prefix - seq # - tag - .ext

prefix - name based on genus, species name; variable length.
seq # - sequence number, allowing for different specimens of same species; 2-3 characters.
tag - indicates type of image, label (lab), illustration (ill), picture (pic), cone (con) etc.; 3 characters.   Note: No tag for original specimen image.
.ext – file extension for type of compression: .JPG, .TIF, .GIF, etc; 3 characters.

Examples:

abba01.tif - the original archived (18 mb) file of Abies balsamea

abba01-con.jpg - the image of the cone for Abies balsamea

abb01-lab.jpg - the label/annotations file from the original archived file

abba02-ill.gif - an illustration or line drawing of Abies balsamea

abba03-pic.jpg - a photograph of a live specimen of Abies balsamea (not expected to be from the original specimen source)