Transformation

Last modified: February 14, 2023

Contents

grey_convert

Image [GreyScale] grey_convert (IntVector newgrey)

Operates on:Image [GreyScale]
Returns:Image [GreyScale]
Category:Transformation
Defined in:transformation.py
Author:Fabian Schmitt and Christoph Dalitz

Converts grey values to the new values provided in the vector newgrey, i.e. val is replaced by newgrey[val].

As this is only implemented for greyscale images, the vector newgrey must be of size 256 and all entries must be in [0,255].


Example 1: grey_convert([255, 254, 253, 252, 251, 250, 249, 248, 247, 246, 245, 244, 243, 242, 241, 240, 239, 238, 237, 236, 235, 234, 233, 232, 231, 230, 229, 228, 227, 226, 225, 224, 223, 222, 221, 220, 219, 218, 217, 216, 215, 214, 213, 212, 211, 210, 209, 208, 207, 206, 205, 204, 203, 202, 201, 200, 199, 198, 197, 196, 195, 194, 193, 192, 191, 190, 189, 188, 187, 186, 185, 184, 183, 182, 181, 180, 179, 178, 177, 176, 175, 174, 173, 172, 171, 170, 169, 168, 167, 166, 165, 164, 163, 162, 161, 160, 159, 158, 157, 156, 155, 154, 153, 152, 151, 150, 149, 148, 147, 146, 145, 144, 143, 142, 141, 140, 139, 138, 137, 136, 135, 134, 133, 132, 131, 130, 129, 128, 127, 126, 125, 124, 123, 122, 121, 120, 119, 118, 117, 116, 115, 114, 113, 112, 111, 110, 109, 108, 107, 106, 105, 104, 103, 102, 101, 100, 99, 98, 97, 96, 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0])

images/GreyScale_generic.png images/grey_convert_plugin_00.png

mirror_horizontal

mirror_horizontal ()

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom, Karl MacMillan, and Christoph Dalitz

Flips the image across the horizontal (x) axis.


Example 1: mirror_horizontal()

images/RGB_generic.png images/mirror_horizontal_plugin_00.png

mirror_vertical

mirror_vertical ()

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom, Karl MacMillan, and Christoph Dalitz

Flips the image across the vertical (y) axis.


Example 1: mirror_vertical()

images/RGB_generic.png images/mirror_vertical_plugin_00.png

resize

Image [OneBit|GreyScale|Grey16|RGB|Float|Complex] resize (Dim dim, Choice [None|Linear|Spline] interp_type)

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Returns:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom, Karl MacMillan, and Christoph Dalitz

Returns a resized copy of an image. In addition to size, the type of interpolation can be specified, with a tradeoff between speed and quality.

If you need to maintain the aspect ratio of the original image, consider using scale instead.

dim
The size of the resulting image.
interp_type [None|Linear|Spline]
The type of interpolation used to resize the image. Each option is progressively higher quality, yet slower.

rotate

Image [OneBit|GreyScale|Grey16|RGB|Float|Complex] rotate (float(-180.00, 180.00) angle, Pixel bgcolor = None, int(1, 3) order = 1)

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Returns:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom (With code from VIGRA by Ullrich Köthe)

Rotates an image.

angle
The angle of rotation (in degrees)
bgcolor
The color to use for pixels outside of the original image bounds. When bgcolor is None, white is used.
order
The order of the spline used for interpolation. Must be between 1 - 3.

Example 1: rotate(32.0, (255, 255, 255), 3)

images/RGB_generic.png images/rotate_plugin_00.png

Example 2: rotate(15.0, 0j, 3)

images/GreyScale_generic.png images/rotate_plugin_01.png

scale

Image [OneBit|GreyScale|Grey16|RGB|Float|Complex] scale (float scaling, Choice [None|Linear|Spline] interp_type)

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Returns:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom, Karl MacMillan, and Christoph Dalitz

Returns a scaled copy of the image. In addition to scale, the type of interpolation can be specified, with a tradeoff between speed and quality.

If you need to change the aspect ratio of the original image, consider using resize instead.

scale
A scaling factor. Values greater than 1 will result in a larger image. Values less than 1 will result in a smaller image.
interp_type [None|Linear|Spline]
The type of interpolation used to resize the image. Each option is progressively higher quality, yet slower.

Example 1: scale(0.5, 2)

images/RGB_generic.png images/scale_plugin_00.png

Example 2: scale(2.0, 2)

images/RGB_generic.png images/scale_plugin_01.png

shear_column

shear_column (int column, int distance)

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom, Karl MacMillan, and Christoph Dalitz

Shears a given column by a given amount.

column
The column number to shear.
distance
The number of pixels to move the column. Positive values move the column downward. Negative values move the column upward.

Example 1: shear_column(50, 10)

images/OneBit_generic.png images/shear_column_plugin_00.png

shear_row

shear_row (int row, int distance)

Operates on:Image [OneBit|GreyScale|Grey16|RGB|Float|Complex]
Category:Transformation
Defined in:transformation.py
Author:Michael Droettboom, Karl MacMillan, and Christoph Dalitz

Shears a given row by a given amount.

row
The row number to shear.
distance
The number of pixels to move the row. Positive values move the row to the right. Negative values move the row to the left.

Example 1: shear_row(50, 10)

images/OneBit_generic.png images/shear_row_plugin_00.png