This section describes &chalk;'s dialog windows. The Color Range dialog The Color Range dialog The Color Range dialog You can create a selection based on the color values of pixels here. In the dropdown box, choose which color range you want to select. Pixels will be selected according to their color value on this scale (⪚ a fully yellow pixel would score maximally on the yellow scale and on the red and green scales). If you check the Invert box, the selection becomes inverted: pixels will become selected if they have a lower value in the specified range instead. You can choose whether the current selection should be added to or subtracted from the color range selection by clicking the respective option: Add to current selection or Subtract from current selection. Choose Select to actually perform the selection or Deselect to remove these pixels from the selection. The Convert Image Type dialog The Convert Image Type dialog The Convert Image Type dialog This dialog allows you to convert your image from one color space to another. The Target color space and Destination ICM profile are used to set to which colorspace and profile the image will be converted. You can influence how this conversion is done with the Rendering Intent option. With Perceptual conversion, the source color space is mapped linearly to the destination color space. If the destination color space accepts a lesser color range than the source, shifts may occur because the range is compressed. Relative colorimetric conversion converts every color to the closest color in the destination color space. This may mean that a certain color range is mapped to one color in the destination color space. Saturation means that fully saturated colors will remain fully saturated, even if this means that the actual color is changed. With Absolute colorimetric conversion, the same approach is used as with Relative colorimetric, but the white point of the color space (the value designating the color white) is not changed to match the new color space, which may result in unwanted changes to near colors. The Image Properties dialog The Image Properties dialog The Image Properties dialog In this dialog you can change a couple of image properties. First of all, the Name of the image. If you did not set a name earlier (that can also be done when creating the image), it will have a default name like Image1. Then, you can set its size (determined by the Width and Height in pixels and the Resolution in dots per inch) and the color profile to be used (Profile). Finally, you can fill in the Description field with any information you want to add to the image. The Image Size dialog The Image Size dialog The Image Size dialog This dialog lets you resize your image. In the top part, you can choose the way the image is resized. If you choose Resize, the size of the image is changed, but its layers (which contain the actual contents) will not be modified. So, when you double the height and width of the image, your original image will occupy the top-left quarter part of your new image. On decreasing the size of your image, the image layers will stretch out over the image borders, unless you choose Crop layers on image resize, which will crop all layers to the new image size. With Scale, the image layers will be resized with the image. So increasing the image size will actually enlarge the contents, and similar for decreasing. Under Pixel dimensions, you can set which new size you want the image to have. The original size is given as a reference. The new size can be set both as pixels or as a percentage, with 100% being the original size. If you select Constrain proportions, the new width and height will always be set to the same percentage. For example, if you have an image of 200 x 100 pixels, and set the width to 20 pixels, the height will automatically be changed to 10. With this checkbox unselected, you can also resize the image non-proportionally. The Filter: dropdown box can be used to select a different algorithm for determining the colors of the pixels in the newly resized image that did not correspond to a pixel in the old image (the calculated corresponding location in the old image was located in between pixels). BSpline uses a 4 x 4 pixel grid and results into a quite high blurring. Bell is quite fast while resulting in a reasonably smooth image. Box is the fastest method, but yields the least appealing result. Hermite keeps the image quite sharp, while smoothing it as well, and is reasonably fast. Lanczos3 results in sharp images, but is very slow. Mitchell (the default) is not very fast, but often yields a good intermediate result. Triangle/Bilinear uses the 2 x 2 pixel grid around the calculated location resulting in relatively sharp lines. The Rotate Image dialog The Rotate Image dialog The Rotate Image dialog With this dialog, you can rotate the image. The top part of the dialog shows the result of the rotation in the form of a change in dimension (if any). Under Direction you can choose between rotating clockwise and counter-clockwise. Under Angle, you can set the amount of rotation. 90, 180 and 270 degrees can be selected using the respective option button, other amounts need to be specified with the Custom spin box. The Separate Image dialog The Separate Image dialog The Separate Image dialog With this dialog, you can separate (part of) your image. Every color component (channel) will be put into a separate layer or image. At the top of the dialog, the current color model is shown. Below that, a couple of options can be set. Under Source, you can choose what part of the image to separate. The two options are Current layer, which (obviously) only uses the currently selected layer and Flatten all layers before separation, which uses the entire image. Under Output, you can choose where the result of the separation should be written to: either to a couple of layers, or to a couple of images. Under Alpha Options, you can choose what should be done with the alpha channel of the selected layer(s). It can be copied to each new channel, be discarded, or separated on its own. The two options at the bottom of the dialog, finally, determine whether the source should be downscaled to 8 bit colors (if it contains more), and whether the output should be in color (default is to separate the channels to grayscale values). The Shear Image dialog The Shear Image dialog The Shear Image dialog This dialog allows you to shear your image. By shearing, the bounding rectangle of your image is transformed into a parallellogram. One pixel row/column is kept in place, the next one is shifted by a certain amount, the next one by the same amount relative to the previous one, etcetera. The X and Y shearing angles can be set using the two spin boxes. The Substrate dialog The Substrate dialog The Substrate dialog (This dialog is still to be described.) The Convert Layer Type dialog The Convert Layer Type dialog The Convert Layer Type dialog This dialog is exactly the same as the Convert Image Type dialog, which converts an entire image instead of a single layer. See the description there for details. The Drop Shadow dialog The Drop Shadow dialog The Drop Shadow dialog With this dialog, you can add a drop shadow effect to the current layer. Select the X and Y offsets (displacements) of the shadow relative to the original layer with the two topmost spin boxes. The Blur radius spinbox determines the radius in which the shadow will be blurred (to achieve a smooth transition at the shadow border). If you want a special color for the shadow, you can choose one with the Color field. The Opacity slider and spinbox can be used to make the shadow more or less transparent. Disable the Allow resizing checkbox if you don't want the layer to be resized in order to give it a shadow. The Histogram dialog The Histogram dialog The Histogram dialog This dialog shows a histogram for the current layer. With the Method: settings, you can choose what kind of histogram to show. You can change the channel(s) to show with the Channels: listbox, and the scale on which it should be drawn with the Linear and Logarithmic radio buttons. Under the preview, there are buttons available to zoom in to, and move over, the histogram. These are activated for 16-bit colorspace layers. The Layer Properties dialog The Layer Properties dialog The Layer Properties dialog This dialog is in essence the same as the New Layer dialog, with the difference that you cannot change its colorspace or profile anymore. These properties are shown, though, to keep the information complete. The Layer Size dialog The Layer Size dialog The Layer Size dialog This dialog allows you to resize the current layer. Under Pixel dimensions, you can set which new size you want the layer to have. The original size is given as a reference. The new size can be set both as pixels or as a percentage, with 100% being the original size. If you select Constrain proportions, the new width and height will always be set to the same percentage. For example, if you have a layer of 200 x 100 pixels, and set the width to 20 pixels, the height will automatically be changed to 10. With this checkbox unselected, you can also resize the layer non-proportionally. The Filter: dropdown list can be used to select a different algorithm for resizing the layer. The New Adjustment Layer dialog The New Adjustment Layer dialog The New Adjustment Layer dialog In this dialog, you can select the type of adjustment layer to add to the image. In the left-hand list, you can see the available adjustment layers, each with a preview. When you select one, the Preview will change to show a correctly scaled preview of what the result of the adjustment layer is going to be. You can then choose to show either the original image or the preview of the adjustment layer with the radio buttons below the preview window. The buttons next to these allow you to zoom in, zoom out, and refresh the preview, respectively. The Autoupdate checkbox determines if the preview window should update automatically after you made a change. The various options available for the filter that is used to create the adjustment layer, are shown at the bottom of the dialog. See the section on filters of this chapter for descriptions. The New Layer dialog The New Layer dialog The New Layer dialog You can add a new layer to your image with this dialog. If you want a descriptive name for your layer, you can fill one in at Name:. You can select the desired colorspace for the new layer from the Colorspace: list, and the specific color profile for that colorspace at Profile:. You can preset the layer's Opacity (you can change it later with the slider in the Layer box), and choose the mode with which the layer should be composited onto the final image. The Rotate Layer dialog The Rotate Layer dialog The Rotate Layer dialog This dialog, similar to the Rotate Image dialog, allows you to rotate the current layer. You can choose the direction in which to rotate and the amount to rotate the layer by. The Shear Layer dialog The Shear Layer dialog The Shear Layer dialog This dialog works the same as the Shear Image dialog, except that it operates on the current layer instead of on the entire image. All filter dialogs consist of a filter-specific part, at the left, and a generic part, at the right. The generic part contains a preview window, which you can configure using the controls below it. Choose Preview or Original depending on whether you want the preview window to show the preview of the filter effect or the original image. The four buttons at the bottom right allow you to zoom in and zoom out, set the zooming factor to 100% (this shows the image at its original size), and refresh the preview, respectively. Furthermore, the option Autoupdate determines if the preview window is updated automatically. If you uncheck this checkbox, you will have to refresh the preview yourself. The Blur dialog The Blur dialog The Blur dialog This dialog allows you to customize the way your image is blurred. The Half-width and Half-height spinboxes determine the size of the areas of your image that are consecutively blurred. With the Strength spinbox you can set the strength with which the blurring should be applied, and with the Angle spinbox you can add a rotation to the area. The Shape setting, finally, allows you to choose between circular and rectangular areas The Brightness / Contrast dialog The Brightness / Contrast dialog The Brightness / Contrast dialog With this dialog, you can customize the brightness and contrast of your image. The curve diagram has a histogram-like background that shows you the abundance of various brightness levels. The curve itself (initially a diagonal line from bottom left to top right) determines to which new brightness level (on the vertical axis) pixels with a certain original level (on the horizontal axis) are to be mapped. For example, the default diagonal line from bottom left to top right sets every original pixel to its own brightness value, meaning no change. A horizontal line means that all pixels will get the same brightness. This means minimal contrast, the brightness itself is indicated by the height at which the line is placed. You can click on a handle (red circle) to select it (a selected handle is indicated by a filled circle) and drag it around to change the shape of the curve. The curve will be drawn smoothly through the handles (always strictly from left to right). If you click on the curve, a handle is added to it at that position. Clicking somewhere else in the image will also add a handle at that point. You can press Delete to delete the currently selected handle. The Bumpmap dialog The Bumpmap dialog The Bumpmap dialog You can apply a bumpmap effect and customize it using this dialog. One layer is used as bumpmap layer: it is read as grayscale image and the gray values of its pixels are used to to distort the other layer for creating the depth illusion. High grey values, &ie; more white, mean a larger height, small values, &ie; near black, mean a smaller height — or a larger depth, the height can get below sealevel. A light source, shining from above on the image that lies on the ground, is simulated to determine the depth and direction of the shadows. The first option in this dialog offers you the selection of the Bumpmap layer. Under Type, you can select what kind of bumpmap to be applied. There are three types, Linear (a normal application of the bumpmap), Spherical (focusing on the extremes, that is, the shadow and highlight values) and Sinusoidal (focusing on the midtone values). Then, there are three options to modify the bumpmap apart from its algorithmical application. With Compensate for darkening, the image is restored to about its original average lightness if using the bumpmap filter would make it darker. The Invert bumpmap option creates an inverted bumpmap (high and low are reversed). With Tile bumpmap, a bumpmap layer that is smaller than the layer it is applied to, will be tiled (repeatedly) to cover the entire layer. Under Settings, you can select the mathematical parameters for the bumpmap. First of all, Azimuth (the angle of the light source in the X-Y plane), Elevation (the height of the simulated light source above the surface in degrees, with 0 degrees being on the ground and 90 degrees being vertically above the image), and Depth (the maximal vertical distortion of the image). Then, there are the X offset and Y offset, with which you can displace the bumpmap layer relative to the destination layer, Water level (the depth seen as neutral), and Ambient light, which determines the relative amount of ambient (environmental) light. The Color Adjustment dialog The Color Adjustment dialog The Color Adjustment dialog This dialog allows you to customize the Color Adjustment filter. You can use the curve (see the section on Brightness / Contrast for a description on the curve) to determine the mapping from old to new color levels, for each of the channels separately. The Color to Alpha dialog The Color to Alpha dialog The Color to Alpha dialog With this dialog, you can make parts of the image having a certain color transparent (officially alpha-transparent). You can select the color you want to remove from the image (replacing it with transparency) with the Color swatch, and how much a color may differ from the selected one before it is considered not to match, with the Threshold spinbox. Setting a threshold of zero (0) ensures that only pixels with the exact matching color will be made transparent, higher thresholds will make other colors match as well. The Color Transfer dialog The Color Transfer dialog The Color Transfer dialog This dialog lets you copy the colors from one image (the Reference Image) to the current one. The colors in both images are compared and each color in the one you are working with, will be replaced by the nearest one in the reference image. The Custom Convolution dialog The Custom Convolution dialog The Custom Convolution dialog With this filter, you can apply a customized distortion effect to your image. The nine spinboxes at the top left determine the distortion. Each pixel is assigned a new value based on these values: the old color values of the pixel inself and the eight surrounding pixels are each multiplied by the values in the respective spinboxes, these results are added, and the final result is the new color value for the pixel. Before being applied, this final result can be multiplied with a certain Factor: or a certain Offset: can be added to it. In the example screenshot, each pixel is assigned a new value based on its own (the 1 in the center), to which are added the values of the pixels to its top right and directly below it (each with a factor of 1, &ie; the actual value, since multiplying by one has no effect), and from which are subtracted the values of the pixels to its bottom right and directly above it (added with a factor of -1, so subtracted by a factor of 1). The Emboss dialog The Emboss dialog The Emboss dialog This dialog contains just one option, the Depth: slider and spinbox which determines the depth of the embossing effect. The Filters Gallery dialog The Filters Gallery dialog The Filters Gallery dialog This dialog can be used to get a quick overview of what the various available filters do. The filters are in turn applied to the current image and the results are put in the left list box as thumbnails. If you select one, its options become available in the Configuration section. See the description of the respective filter for details. The Gaussian Noise Reduction dialog The Gaussian Noise Reduction dialog The Gaussian Noise Reduction dialog This dialog allows you to customize a Gaussian noise reduction. The Threshold setting is a measure for how much noise should be removed (&ie; how quickly a lonely pixel should be made equal to its surroundings), while the Window Size setting determines the radius of the area considered when changing pixels. The Lens Correction dialog The Lens Correction dialog The Lens Correction dialog With this dialog, you can fix an image which is distorted due to common lens anomalies. You can specify a Distortion correction, indicating how much the image should be corrected if its concaveness / convexness is not right, for areas near the center and areas near the edges. If you want an asymmetrical correction, you can specify different X and Y coordinates for the center (in percentages of the total width and height, measured from the top left). You can also correct a too light or too dark image with the Brightness correction spinbox. The Image Restoration dialog The Image Restoration dialog The Image Restoration dialog Using this dialog, you can specify exactly how the image restoration should be done. This filter tries to increase the quality of an image, for instance by removing scratches. Various options are available to customize its behaviour. (Unfortunately, these are not described as of yet.) The Oilpaint dialog The Oilpaint dialog The Oilpaint dialog This dialog can configure two parameters for the associated filter. The Brush size: setting determines the size of the brush that is used to simulate the oilpaint effect, the Smooth: setting specifies if the difference in colors between adjacent swatches may be large (low smoothness) or should be small (high smoothness). The Pixelize dialog The Pixelize dialog The Pixelize dialog On this dialog, you can adjust two settings. Pixel width: and Pixel height: indicate the width and height of the area that should be taken together and averaged to form one new, large pixel. The Raindrops dialog The Raindrops dialog The Raindrops dialog This filter can be configured using the settings Drop size: (the average diameter of the raindrops), Number: (the number of raindrop effects that should be added to the image), and Fish eyes: (the percentage of raindrops that should be rendered as fisheye lens effects instead of plain raindrop effects). The Random Noise dialog The Random Noise dialog The Random Noise dialog This filter adds random noise (speckles, or something similar) to your image. There are two customizable settings: the amount of noise (Level, as a percentage) and the Opacity of the noise (should the original color still be a bit visible or not). The Random Pick dialog The Random Pick dialog The Random Pick dialog In this dialog, you can specify parameters for the Random Pick filter. The Level setting determines how much pixels will be affected (measured as a percentage), the area which is looked in to take a new color for a pixel is set with the Size of the window setting, and the Opacity of the modifications can be set as well. The Round Corners dialog The Round Corners dialog The Round Corners dialog This dialog has one setting: the radius of the rounded corners. The Small Tiles dialog The Small Tiles dialog The Small Tiles dialog In this dialog, you can set the amount of subdivisions with the Number of tiles settings. The Sobel dialog The Sobel dialog The Sobel dialog Here, you can set the parameters for the Sobel edge detection filter. First of all you can determine which directions to sobel in: horizontally, vertically, or both. The Keep sign of result setting does not affect regular images. Make image opaque determines whether the resulting image is opaque or transparent. The Unsharp Mask dialog The Unsharp Mask dialog The Unsharp Mask dialog This dialog offers three options for the sharpening filter Unsharp Mask: the radius (Half-size) of the mask, the Amount of sharpening that should be done, and the Threshold level. The Wave dialog The Wave dialog The Wave dialog For both the horizontal and the vertical components of the wave distortion (note: a vertical wave means that the vertical position is dependent on the horizontal one, and hence looks like a W), you can determine four settings here. The Wavelength (a shorter wavelength means a more erratical wave), the Shift (which point of the wave should be started at), the Amplitude (the amount of distortion), and the Shape (Sinusoidal or rounded, versus Triangle or pointy). The Wavelet Noise Reduction dialog The Wavelet Noise Reduction dialog The Wavelet Noise Reduction dialog The only setting here, Threshold, indicates how easily pixels are seen as noise that should be removed and made equal to the surrounding area. The Add Palette dialog The Add Palette dialog The Add Palette dialog With this dialog, you can add a custom color palette to &chalk;. Fill in the name for your palette in the text field at the top. Then make the palette: use the button Add New Color... to add a color to the palette and Remove Selected Color to remove the currently selected color. Click the button Add to Predefined Palettes to add your newly created palette to the palette list, or just choose OK when you're done. The Document Information dialog The Document Information dialog The Document Information dialog This dialog is the same as in other &koffice; programs. You can enter various information about your document here, which will be saved with the document so that you can retrieve it later to review or edit. On the General tab, you can enter the title, subject and keywords, as well as an abstract. On the bottom of this tab, some statistical information is displayed. On the Author tab, you can store information about yourself. The third tab, User-defined Metadata, allows you to store any other information.