Rotates images by integer multiples of 90 degrees, or mirrors images horizontally or vertically. [more]

Categories: Geometry

Keywords: image rotation, image mirroring, fast rotations




The FastRotation process implements orthogonal and specular geometric transformations: rotate 180 degrees, rotate 90 degrees clockwise, rotate 90 degrees counter-clockwise, horizontal mirror and vertical mirror. These operations are collectively knwown as fast rotations on the PixInsight/PCL platform.

The most important feature of all fast rotations is that these transformations don't interpolate pixel values; they copy and exchange pixels exclusively to generate the rotated or mirrored output image, and hence apply lossless transformations (also knwon as nondestructive transformations). As far as no pixel is cropped (which never happens with the FastRotation tool), you could apply an unlimited number of fast rotations to an image, and the original pixel values would be preserved in the final image (they would only change their positions with respect to the original).


Rotation mode

The table below exemplifies the three rotations available in the FastRotation tool.

Table 1
Rotation Operation

Original Image

Rotated Image


Mirror mode

The following table shows the two mirroring operations available in the FastRotation tool.

Table 2
Mirroring Operation

Original Image

Mirrored Image


Related Tools

Rotation, DynamicCrop