The Digilib Properties View offers a range of advanced facilities to work with an image.
- The "Image Information" property shows data items including the original height and width values of the image on the server. Both values can not be changed.
- The "DPI" property gives the resolution settings of the client display. These properties are used for the original-size scaling feature only (put "osize" in mode flags under "Rotation and Mirroring". The default display resolution setting is -1. The values can be changed. Click the button "redraw" to set the changes in the Image Editor.
- "Rotation and Mirroring" is the next column. On one hand the flags for the mode of operation can be changed here. The default setting is "fit" which means that the image is scaled to fit the screen, another value would be "clip" which does not scale the image but only shows a cropped portion. On the other hand the rotation angle of the image can be set manually. Click the button "redraw" to see the changes in the Image Editor. The image is rotated clockwise by the respective angle in degrees.
- "Color" enables the user to change the
colours, the brightness and the contrast of the image. There are
two ways to modify the colour. Different numeric values in the
three coordinates lead to changes in colour intensity and colour
shade:
- by addition (RGB): This property works like the brightness slider for each colour channel and adds a value to each pixel colour. The three coordinates stand for the primary colours red, green and blue. The values can range from -255 to 255 (and bigger if multiplication is used).
- by multiplication (RGB): This property works like the contrast slider for each colour channel and multiplies the value of each pixel colour. Here the user can vary saturation level of the primary colours red, green and blue in the image by modifying the coordinate numbers. The values can range from -8 to 8.
- The value of overall brightness can be modified by a numeric value also. This value is added to all pixel color values. Positive values make the image lighter, negative values darker. The values can range from -255 to 255 (and bigger if contrast is used).
- The overall contrast can also be changed. This value is multiplied with all pixel color values. Positive values enhance the contrast, negative values reduce the contrast. The values can range from -8 to 8. When you raise the contrast in this setting you have to compensate for the increased overall pixel values by negative brightness values. The contrast slider in the Toolbar does this automatically.
- "Size and Scaling" offers a few opportunities to change the zoom area (relative height, width and offset) and overall size of the image (destination height and width):
-
- relative height of the zoom area as a fraction of image height. Value 0-1.
- destination width of the image in pixels
- additional scaling factor for the destination size which allows the user to enlarge the whole image
- relative y offset of the zoom area as a fraction of image height. Value 0-1.
- relative x offset of the zoom area as a fraction of image width. Value 0-1.
- destination height of the image in pixels
The context menu is disabled in the Properties View.