OptionalignoreGets or sets a value indicating whether a button's appearance should be scaled to fit fully within the bounds of the annotation without taking into consideration the line width of the border.
Not specified means false.
OptionalmodeThe scaling mode. Not specified means "Always".
OptionalpositionGets or sets the position of an image. The two numbers between 0.0 and 1.0 indicate the fraction of leftover space to allocate at the left and bottom of an image. A value of (0.0, 0.0) positions the image at the bottom-left corner of the button rectangle. A value of (0.5, 0.5) centers it within the rectangle. This value is used only if the image is scaled proportionally.
Not specified means { 0.5, 0.5 }
OptionalproportionalIndicating whether an image should be scaled proportionally. Note specified means true.
Represents image alignment within a rectangle in a PDF.