Transform Operators - Images

Many transform toolbar commands are versions of commands that also appear in the main Image menu. The hyperlinks below will jump to the Help topic for the corresponding command. Most commands are enabled for RGB or RGBa images. To use these commands with other types of images, first convert them to RGB or RGBa images.

Add Margin	Add to the rectangular size of the image by the given number of pixels at the margin.
Add Noise	Add color noise as set by the argument. A transform toolbar version of the Noise menu command.
Add Noise (Mono)	Add monochrome noise as set by the argument. A transform toolbar version of the Noise menu command with Monochromatic mode checked.
Auto Contrast	Automatically adjust contrast to balance contrast non-linearly throughout the entire image considering the overall intensity of each pixel.
Auto Level	Balance contrast throughout the entire image by balancing contrast within each channel individually.
Blur	Blur image by fixed amount. Blurs both features and colors. For a "blur" effect that does not mix colors, use the Median filters.
Blur (parameter)	Blur image by the number of pixels given in the argument. This blur is implemented as a matrix operator where the value of the argument is the weight of the center pixel with weights of all other pixels set to 1. Increasing the value therefore produces a lesser blur.
Brightness	Adjust brightness by the argument amount.
Contrast	Adjust contrast by the argument amount.
Crop	Crop image size to the selection.
Crop Margin	Crop the rectangular size of the image by the given number of pixels at the margin.
Desaturate	Reduce saturation to zero for all color values. Remains RGB.
Difference East	Detect and emphasize edge transitions to the East. See the Filters topic for general discussion of convolution matrix filters like this one.
Difference North	Detect and emphasize edge transitions to the North.
Difference North-East	Detect and emphasize edge transitions to the North-East.
Difference North-West	Detect and emphasize edge transitions to the North-West.
Difference South	Detect and emphasize edge transitions to the South.
Difference South-East	Detect and emphasize edge transitions to the South-East.
Difference South-West	Detect and emphasize edge transitions to the South-West.
Difference West	Detect and emphasize edge transitions to the West.
Diffuse	Migrate pixels by swapping them in a "random walk." Reapplying Diffuse several times will move pixels further and further away from their original positions.
Equalize	Equalize image to value given in the argument.
Flip Horizontally	Flip image left / right to mirror image. If a rectangular selection is present, the selection only can be flipped.
Flip Vertically	Flip image top / bottom to upside down image. If a rectangular selection is present, the selection only can be flipped.
Gamma	Alter gamma value by the argument.
Gaussian Blur	True Gaussian probability function blur by given amount. Slow to compute for very large images.
Grayscale	Cast all colors into gray tones by intensity. Remains RGB.
High Pass 1	Emphasize rapid transitions between pixels. Good edge detection with horizontal and vertical lines.
High Pass 2	Stronger emphasis on rapid transitions between pixels with strong edge detection on lines of all angles.
High Pass 3	Edge detection with crisp vertical and horizontals and fuzzy lines at other angles.
Invert	Invert pixel values so that 0 becomes 255 and 255 becomes 0. See the Invert topic for information on the Invert At transform.
Laplace 1	Good edge detection with emphasis on horizontal and vertical changes.
Laplace 2	Strongest changes at point of intersection of horizontal and vertical lines, resulting at a small X pixel pattern at the point of intersection; fuzzy detection of linear features at other angles.
Low Pass 1	Strong blur, with strong suppression of large pixel to pixel changes.
Low Pass 2	Blur, with medium suppression of large pixel to pixel changes.
Low Pass 3	Blur, with least suppression of large pixel to pixel changes. Removes graininess in some images.
Median Cross	Evens out color tending to preserve horizontal and vertical features. A "blur" that ignores perfectly horizontal and vertical linear features.
Median Square	Evens out color looking at a 3 x 3 matrix surrounding each pixel. A "blur" that preserves prevailing color.
Median Square 5	Strong evening out of color looking at a 5 x 5 matrix surrounding each pixel. Results in removal of isolated pixels of color differing greatly from surrounding pixels. A stronger "blur" effect that preserves prevailing color.
Motion Blur Diagonal 1	Blurs the image as if moved diagonally on the upper left / lower right axis by the specified number of pixels. See the Image - Motion Blur topic.
Motion Blur Diagonal 2	Blurs the image as if moved diagonally on the upper right / lower left axis by the specified number of pixels. See the Image - Motion Blur topic.
Motion Blur Horizontal	Blurs the image as if moved horizontally by the specified number of pixels. See the Image - Motion Blur topic.
Motion Blur Vertical	Blurs the image as if moved vertically by the specified number of pixels. See the Image - Motion Blur topic.
Posterize	Converts the image to a limited number of colors for a "poster" effect. Very low (2, 3 or 4) parameter values gives the most obvious effect.
Rotate	Rotate image given number of degrees. Negative degrees are taken as counter-clockwise rotation.
Sharpen	Emphasize transitions to give images a sharper appearance.
Sharpen (parameter)	A Sharpen with selectable value for degree of sharpness. This sharpen is implemented as a matrix operator where the value of the argument is the weight of the center pixel with weights of all other pixels set to 1. Increasing the given value therefore produces less sharpening.
Sharpen More	Enhanced sharpness compared to standard Sharpen.
Threshold	Converts an image into black and white based on whether each pixel is above or below the given value in intensity.
Threshold Black	Like Threshold, but forces all pixels below the intensity given in the source / argument box into black while leaving all pixels above that value unchanged.
Threshold White	Like Threshold, but forces all pixels above the given intensity into white while leaving all pixels below that value unchanged.
Tile	Divides image into tiles of given X and Y extent and then averages pixel values within the tiles. This is used for aggregating and interpolating raster data images into larger tiles and for creating "pixelated" artistic effects.
Tile Median	Equivalent to Tile command with Preserve Colors checkbox checked.

Many commands in the Transform toolbar are based on convolution matrix filters. See the Image - Filter topic for a detailed discussion of how matrices are used in filter effects and how to create new filter-based commands that may be added to the Transform toolbar.

Image Menu Commands

Many transform commands are one-line versions of commands available in the Image menu. The image menu appears when the focus is on an image window or an image layer is active in a map. Commands listed below will appear either under the main Image menu or under submenus such as Adjust or Effects. Commands are enabled for RGB or RGBa images. To use these commands with other types of images, first convert them to RGB or RGBa images.

Open Palette	Enabled for palette images. Open the palette for this
Dither	Uses a smaller number of colors in an image while preserving a perceptual effect through the use of dither patterns.
Quantize	Convert image to the specified number of colors using enhanced or standard methods.
Resize	Change the size of the image using desired interpolation method.
Convert To	Convert images between grayscale, palette, RGB or RGBa images.
Adjust Menu
Color Balance	Adjust RGB color values for Shadows, Midtones or Highlights
Brightness / Contrast	Change brightness and contrast.
Hue / Saturation	Alters hue, saturation and lightness.
Invert	Invert pixel channel value. Creates a "photographic negative".
Equalize	Alters individual pixel brightness so there is an equal number of pixels at all brightness levels.
Gamma	Change mid-tone color brightness.
Threshold	Forces grayscale pixels to white, black or unchanged based on a histogram.
Threshold Color	Like Threshold but applies to each RGB channel individually.
Posterize	Convert image to a limited number of colors for a "poster"
Effects Menu
Colorize	Adjust saturation and hue while keeping intensity the same, as if a color were applied to a grayscale version of the image.
Gaussian Blur	Apply Gaussian bell curve blurring to create shadows, halos and transitions.
Motion Blur	Streaked effect in the desired direction.
Diffuse	Moves pixels by swapping them in a "random walk."
Filter	Applies convolution filters, either custom filters or a choice from numerous presets.
Fluoresce	Alter saturation and lightness in asymmetric ways to cause some colors to appear unusually bright.
Noise	Add random monochromatic or color pixels.
Relief	Add highlights and shadows to give a 3D effect to 2D images.
Simplify	Aggregates pixels into larger clumps for a pointillist or mosaic tile effect. Can also remove small dots in cartographic work.
Tile	Convert image into rectangular tiled regions of appropriate color.