TINMAN 3D / REALTIME TERRAIN
Software Development Kit - User Manual

class ImageReaderBase in Tinman.Terrain.Imaging

Abstract base class for IImageReader implementations.

abstract class ImageReaderBase extends Disposable
  implements IImageReader
  base of ImageReader

Configuration

ToConfig

Returns the configuration value that describes this object.

public method ToConfig ()
type ConfigValue
returns [not-null] The configuration value.
implements IConfigurable.ToConfig

Remarks:

All configurable objects need to implement this interface. For simple types, it is preferable to delegate to ToValue.

The returned value may be of type Invalid, which means that this object in its current state cannot be described with the configuration API.

Before returning the resulting configuration value, Cache must be called on it, passing this IConfigurable object as parameter.

Exceptions:

Protected / Attributes

flags

The set of ReadImageFlags that has been used to create this image reader.

protected readonly field flags
type ReadImageFlags

IsReadingData

Will this ImageReaderBase object be used to read actual image data?

protected property IsReadingData { get }
type bool
value true if image data will be read, false if only metadata will be read.

IsReadingGeo

Will this ImageReaderBase object be used to read geo-referencing metadata?

protected property IsReadingGeo { get }
type bool
value true if geo-referencing metadata will be read, false if not.

Protected / Constructors

ImageReaderBase

Creates a new instance of ImageReaderBase.

protected constructor ImageReaderBase (ReadImageFlags flags)
params flags The set of ReadImageFlags for this image reader.

Protected / Methods

DisposeResources

Disposes the resources held by a concrete subclass. This method will be called exactly once per instance.

protected virtual method DisposeResources ()
inherited Disposable.DisposeResources

Remarks:

This method will be called as soon as all ownership references to this instance have been relinquished by calls to the Dispose method.

The system may garbage collect an instance of IDisposable iff there are no more references to it. In this case, the DisposeResources will be called, in order to avoid dangling resources. However, it is not advisable to rely on the garbage collection of the system, as the behaviour may differ significantly between environments. Instead, ownership rules should be obeyed, which effectively removes the need for automatic garbage collection.

Overriding methods must call the DisposeResources method of their base class. The base call should be the last statement.

InitializeBegin

Begins to initialize this object.

protected method InitializeBegin ()
type bool
returns true if initialization must be performed,
false if initialization has already been performed.
inherited Disposable.InitializeBegin

InitializeRequired

Has this object been initialized?

protected method InitializeRequired ()
type bool
returns true if Initialize has already been called,
false if not.
inherited Disposable.InitializeRequired

Public / Attributes

Coverage

The pixel coverage of the image.

public abstract property Coverage { get }
type PixelCoverage
value The pixel coverage.
overrides IImageInfo.Coverage

Remarks:

Usually, images have a pixel coverage of PixelIsArea.

Gamma

The gamma correction that must be applied to normalized image pixels in order to obtain linear pixel values.

public abstract property Gamma { get }
type float64
value The gamma correction value (see remarks).
overrides IImageInfo.Gamma

Remarks:

Depending on the value V of this property, the following gamma correction is applied:

See also:

IImageReader

Georef

Returns geo-referencing information.

public abstract property Georef { get }
type Raster
value The geo-referencing object or null if no geo-referencing is available.
overrides IGeorefInfo.Georef

HasFinished

Has the image reader finished (i.e. the whole image has been read)?

public abstract property HasFinished { get }
type bool
value true if the whole image has been read, false if not.
overrides IImageReader.HasFinished

Height

Height of the image, in pixels.

public abstract property Height { get }
type int32
value [>0] Height of the image, in pixels.
overrides IImageInfo.Height

Remarks:

This is the number of image pixels along the Y-axis, which may be different from the raster height (see MapInfo), depending on the pixel coverage.

ImageFormat

The file format of the image file.

public abstract property ImageFormat { get }
type ImageFormat
value [not-null] The image file format.
overrides IImageInfo.ImageFormat

Remarks:

The default file format is Any, which will try to load image data using any of the available image formats.

IsSoleOwnership

Will this object be disposed upon the next call to Dispose?

[ThreadSafe]
public property IsSoleOwnership { get }
type bool
value true if the object will be disposed when Dispose is called,
false if the object will not be disposed, because some other code is still holding shared ownership (see AcquireThrow).
inherited Disposable.IsSoleOwnership

Layer

The heightmap layer which shall receive the data of this image.

public abstract property Layer { get }
type HeightmapLayer
value The target heightmap layer.
overrides IImageInfo.Layer

Remarks:

This is not an actual property of the image, but included here for convenience when images are imported into heightmap datasets.

LifecycleState

Returns the lifecycle state of this object.

public property LifecycleState { get }
type LifecycleState
value The lifecycle state.
inherited Disposable.LifecycleState

Map

Returns a MapInfo value that describes the used map raster.

[Constant]
public abstract property Map { get }
type MapInfo
value The map info value.
overrides IMapInfo.Map

NoData

The raw pixel value that represents missing data (i.e. void pixels).

public abstract property NoData { get }
type float64
value The nodata value.
overrides IImageInfo.NoData

Remarks:

The default value is NanD (i.e. all raw pixel values are valid).

See also:

IImageReader

PathInfo

Returns a Path object that represents the file path this object is associated with.

public abstract property PathInfo { get }
type Path
value [not-null] The path info.
overrides IPathInfo.PathInfo

Remarks:

Objects that do not have a meaningful file path association simply return Unknown.

PixelFormat

The pixel format of the image.

public abstract property PixelFormat { get }
type PixelFormat
value The pixel format of the image.
overrides IImageInfo.PixelFormat

Remarks:

Image processing is always performed with with four 24-bit integer channels (see Scanline). The pixel format provides additional information about the stored pixel data.

Range

The mapping between raw pixels values and normalized image pixels.

public abstract property Range { get }
type PixelRange
value The pixel range.
overrides IImageInfo.Range

See also:

IImageReader

ScanlineY

The Y-coordinate that will be read upon the next call to ReadScanline.

public abstract property ScanlineY { get }
type int32
value [0..Height] The scanline Y-coordinate.
overrides IImageReader.ScanlineY

Width

Width of the image, in pixels.

public abstract property Width { get }
type int32
value [>0] Width of the image, in pixels.
overrides IImageInfo.Width

Remarks:

This is the number of image pixels along the X-axis, which may be different from the raster width (see MapInfo), depending on the pixel coverage.

Public / Methods

Acquire

Acquires a strong reference to this disposable object.

[OwnerReturn, Pure]
public method Acquire ()
type IImageReader
returns The strong reference to this disposable object or null iff this object is no longer valid.

Remarks:

The object will not be actually disposed by calls to Dispose when there is at least one strong reference left. Code that calls this method is responsible for calling the Dispose method accordingly.

This method is not intended to be used in performance-critical code. It should only be used to high-level resource management.

AcquireBase

Acquires a strong reference to this disposable object.

[OwnerReturn, Pure]
public method AcquireBase ()
type IDisposable
returns The strong reference to this disposable object or null iff this object is no longer valid.
inherited Disposable.AcquireBase

Remarks:

The object will not be actually disposed by calls to IDisposable when there is at least one strong reference left. Code that calls this method is responsible for calling the IDisposable method accordingly.

This method is not intended to be used in performance-critical code. It should only be used to high-level resource management.

Using this method usually requires type casting. Subclasses may additionally implement IDisposableGeneric, in order to provide some syntactic sugar for that.

AcquireThrow

Acquires a strong reference to this disposable object.

[OwnerReturn, Pure]
public method AcquireThrow ()
type IDisposable
returns [not-null] The strong reference to this disposable object.
inherited Disposable.AcquireThrow

Remarks:

The object will not be actually disposed by calls to IDisposable when there is at least one strong reference left. Code that calls this method is responsible for calling the IDisposable method accordingly.

This method is not intended to be used in performance-critical code. It should only be used to high-level resource management.

Exceptions:

Adjust

Adjust the brightness and saturation of this image.

[OwnerReturn, OwnerThis]
public virtual method Adjust (int32 brightness, int32 saturation)
type IImageReader
params brightness [-1000..1000] The adjustment factor for image brightness.
  saturation [-1000..1000] The adjustment factor for image saturation. Defaults to 0.
returns [not-null] The resulting image.

See also:

Colors.Adjust

AlphaToCoverage

Converts the alpha channel (see Alpha) of this image to a coverage layer (see Void).

[OwnerReturn, OwnerThis]
public virtual method AlphaToCoverage ()
type IImageReader
returns [not-null] The resulting image.

Background

The image scanlines will be read using concurrent background tasks.

[OwnerReturn, OwnerThis]
public virtual method Background ()
type IImageReader
returns [not-null] The resulting IImageReader object.

ChannelToIntensity

Returns an opaque grayscale image which pixel values are equal to the given pixel channel of this image.

[OwnerReturn, OwnerThis]
public virtual method ChannelToIntensity (PixelChannel channel)
type IImageReader
params channel The pixel channel.
returns [not-null] The resulting image.

Remarks:

Void pixels in this image will also be void in the resulting image.

See also:

IImageOps.IntensityToChannel

Clip

Returns an image that represents a sub rectangle of this image.

[OwnerReturn, OwnerThis]
public virtual method Clip (int32 x, int32 y, int32 width, int32 height)
type IImageReader
params x [>=0] X-coordinate of top-left corner of rectangle.
  y [>=0] Y-coordinate of top-left corner of rectangle.
  width [>0] Width of rectangle.
  height [>0] Height of rectangle.
returns [not-null] The resulting image.

Crop

Assumes the image holds a non-rectangular shape that is padded with a uniform color and replaces all padding pixels with void.

[OwnerReturn, OwnerThis]
public virtual method Crop (int64 color = Colors.Black, int32 skip = 1)
type IImageReader
params color The padding pixel color (see Colors). Defaults to Black.
  skip The maximum length (in pixels) of a run surrounded by void pixels that will be interpreted as void, too. Defaults to 1.
returns [not-null] The resulting image.

Remarks:

Since the source image is read scanline after scanline, cropping is performed locally for each scanline: Beginning at the left and right image borders, all pixels having the same color as the color parameter are replaced with void until a consecutive run of pixels having different colors is found (see skip). The following figures illustrates this: Pixels that have the same color as the color parameter are shown as '.' characters, all others are indicated with X:

+-----------------------------------------------------------------------+
|.......................................................................|
|.......................................................................|
|............................XXX........................................|
|...........................XXXXX.......................................|
|.........................XXXXXXX.......................................|
|.......................XXXXXXXXX.......................................|
|.....................XXXXXXXXXXX.......................................|
|...................XXXXXXXXXXXXXX......................................|
|.................XXXXXXXXXXXXXXXX......................................|
|................XXXXXXXXXXXXXXXXX......................................|
|...............XXXXXXXXXXXXXXXXXXX.....................................|
|................XXXXXXXXXXXXXXXXXXX....................................|
|.................XXXXXXXXXXXXXXXXXXXXX.................................|
|...................XXXXXXXXXXXXXXXXXXXXXXX.....X.......................|
|...............XXXXXXXXXX..XXXXXXXXXXXXXXXXXXXXXXXXXXX.................|
|..........XXXXXXXXXXXX.......XXXXXXXXXXXXXXXXXXXXXXXXXXX...............|
|.............XXXXXXX..........XXXXXXXXXXXXXXXXXXXXXXXXXX...............|
|...............XXX.............XXXXXXXXXXXXXXXXXXXXXXXX................|
|................................XXXXXXXXXXXXXXXXXXXXX..................|
|................................XXXXXXXXXXXXXXXXX......................|
|...................................XXXXXXX.............................|
|.......................................................................|
|.......................................................................|
|.......................................................................|
|.......................................................................|
+-----------------------------------------------------------------------+
The cropped image will look like this (whitespace represents void pixels):
+-----------------------------------------------------------------------+
|                                                                       |
|                                                                       |
|                            XXX                                        |
|                           XXXXX                                       |
|                         XXXXXXX                                       |
|                       XXXXXXXXX                                       |
|                     XXXXXXXXXXX                                       |
|                   XXXXXXXXXXXXXX                                      |
|                 XXXXXXXXXXXXXXXX                                      |
|                XXXXXXXXXXXXXXXXX              cropped because         |
|               XXXXXXXXXXXXXXXXXXX             of skipped pixels       |
|                XXXXXXXXXXXXXXXXXXX            |                       |
|                 XXXXXXXXXXXXXXXXXXXXX         V                       |
|                   XXXXXXXXXXXXXXXXXXXXXXX                             |
|               XXXXXXXXXX..XXXXXXXXXXXXXXXXXXXXXXXXXXX                 |
|          XXXXXXXXXXXX.......XXXXXXXXXXXXXXXXXXXXXXXXXXX               |
|             XXXXXXX..........XXXXXXXXXXXXXXXXXXXXXXXXXX               |
|               XXX.............XXXXXXXXXXXXXXXXXXXXXXXX                |
|                         ^      XXXXXXXXXXXXXXXXXXXXX                  |
|                         |      XXXXXXXXXXXXXXXXX                      |
|                  not reachable    XXXXXXX                             |
|                  from left or                                         |
|                  right border                                         |
|                                                                       |
|                                                                       |
+-----------------------------------------------------------------------+
Cropping will not change the image size or modify the geo-reference.

Dispose

Releases all resources held by this object if there are no more strong references to it, decrements the reference counter by one otherwise.

[Dispose, OwnerThis, ThreadSafe]
public method Dispose ()
inherited Disposable.Dispose

Remarks:

The Dispose method silently returns if the object has already been disposed.

Implementing methods must not throw any exceptions.

Function

Transform linear pixel values using a custom function.

[OwnerReturn, OwnerThis]
public method Function (string function, PixelChannel channel = PixelChannel.Intensity)
type IImageReader
params function [not-null] A function expression (see GrammarRuleExpression) that consumes input linear pixel values in the range [0..1] and returns output linear pixel value in the range [0..1]. Output values are clamped (including infinities), not-a-number output values produce void pixels (see Void).
  channel The pixel channel the function shall be applied to. If Void, no transformation will be performed. Defaults to Intensity.
returns [not-null] The resulting image or this if channel is Void.

Remarks:

The given function is evaluated on linear pixel values, that is after raw pixels have been translated to normalized pixel values (see SetRange) and after gamma correction has been applied (see SetGamma). The expression may use all members of the default Tinman script (see Tinman). The following arguments are available to the function expression:

IntensityToChannel

Returns an image that has a single pixel channel (see channel parameter), initialized to the grayscale intensities of this image. All other pixel channels are initialized to their respective default values (see PixelChannel).

[OwnerReturn, OwnerThis]
public virtual method IntensityToChannel (PixelChannel channel)
type IImageReader
params channel The pixel channel.
returns [not-null] The resulting image.

Remarks:

Void pixels in this image will also be void in the resulting image.

See also:

IImageOps.ChannelToIntensity

Replaces a pixel channel of the given image with the grayscale intensities of this image.

[OwnerReturn, OwnerThis]
public virtual method IntensityToChannel (PixelChannel channel, [Owner] IImageReader image)
type IImageReader
params channel The pixel channel to replace.
  image [not-null] The image which pixel channel is to be replaced.
returns [not-null] The resulting image.

Remarks:

Void pixels in the other image are ignored (i.e. the original pixel remains unchanged). Void pixels in this image are preserved (i.e. the other pixel is ignored).

See also:

PixelChannel

Invert

Inverts the given pixel channel.

[OwnerReturn, OwnerThis]
public virtual method Invert (PixelChannel channel)
type IImageReader
params channel The pixel channel.
returns [not-null] The resulting image.

Remarks:

The Void pixel channel cannot be inverted. The method will do nothing in this case.

Op

Combines this image (first) with the given one (second) using the specified color operation (see ColorOp).

[OwnerReturn, OwnerThis]
public virtual method Op ([Owner] IImageReader other, ColorOp colorOp)
type IImageReader
params other [not-null] The other image.
  colorOp The color operation to apply.
returns [not-null] The resulting image.

Pad

Pads this image by duplicating pixels at the borders.

[OwnerReturn, OwnerThis]
public virtual method Pad (int32 amount = 1)
type IImageReader
params amount [>=0] The pad amount, in pixels. Defaults to 1.
returns [not-null] The resulting image.

Remarks:

Padding can be used to reduce seams that will occur when tiled geodata is imported incrementally using on-the-fly projection. The correct solution would be to merge all geodata tiles into a dataset and then perform the projection on the whole geodata.

ReadAll

Reads the entire image into a color buffer.

[OwnerThis]
public abstract method ReadAll ()
type ColorBuffer
returns [not-null] The color buffer.
overrides IImageReader.ReadAll

Remarks:

This method must only be called when the current scanline is zero (see ScanlineY).

Exceptions:

ReadScanline

Reads the next scanline.

public abstract method ReadScanline (Scanline scanline)
type int32
params scanline [not-null] The output buffer for the read scanline pixels.
returns Y-coordinate of processed scanline.
overrides IImageReader.ReadScanline

Exceptions:

Scale

Returns an image that represents a scaled version of this image.

[OwnerReturn, OwnerThis]
public virtual method Scale (int32 width, int32 height, InterpolationMode mode = InterpolationMode.UniformB)
type IImageReader
params width [>0] Width of the scaled image.
  height [>0] Height of the scaled image.
  mode The interpolation mode to use for magnification. Defaults to UniformB.
returns [not-null] The resulting image.

SetCoverage

Updates the value of Coverage, without modifying the image content.

[OwnerReturn, OwnerThis]
public abstract method SetCoverage (PixelCoverage coverage)
type IImageReader
params coverage The pixel coverage.
returns [not-null] The resulting image.

Remarks:

To perform resampling between pixel-is-area and pixel-is point, use ToCoverage.

SetGamma

Updates the value of Gamma.

[OwnerReturn, OwnerThis]
public abstract method SetGamma (float64 gamma)
type IImageReader
params gamma The gamma correction.
returns [not-null] The resulting image.

SetGeoref

Updates the value of Georef, without modifying the image content.

[OwnerReturn, OwnerThis]
public abstract method SetGeoref (Raster georef)
type IImageReader
params georef The geo-referencing information or null.
returns [not-null] The resulting image.

SetLayer

Updates the value of Layer, without modifying the image content.

[OwnerReturn, OwnerThis]
public abstract method SetLayer (HeightmapLayer layer, PixelFormat format = PixelFormat.Unknown)
type IImageReader
params layer The heightmap layer.
  format The pixel format to use for choosing the heightmap format (see For). If Unknown, the pixel format of this image will be used. Defaults to Unknown.
returns [not-null] The resulting image.

SetNoData

Updates the value of NoData.

[OwnerReturn, OwnerThis]
public abstract method SetNoData (float64 noData)
type IImageReader
params noData The raw pixel value to map to void pixels (see NoData).
returns [not-null] The resulting image.

SetRange

Updates the value of Range.

[OwnerReturn, OwnerThis]
public abstract method SetRange (PixelRange range, bool reinterpret = false)
type IImageReader
params range The pixel value ranges to use for translating raw pixel values to normalized pixel values (see Range).
  reinterpret true to leave raw pixels values unchanged and reinterpret them according to range, false to normalize raw pixel values to range. Defaults to false.
returns [not-null] The resulting image.

SkipScanlines

Skips the given number of scanlines.

public abstract method SkipScanlines (int32 count)
params count [>=0] The number of scanlines to skip.
overrides IImageReader.SkipScanlines

Exceptions:

Smooth

Performs smoothing on this image.

[OwnerReturn, OwnerThis]
public method Smooth ()
type IImageReader
returns [not-null] The resulting image.

Remarks:

Image smoothing is performed using an Uniform-B spline.

ToCoverage

Transforms this image from the given pixel coverage semantic to the given one.

[OwnerReturn, OwnerThis]
public virtual method ToCoverage (PixelCoverage target, bool wrapX = false)
type IImageReader
params target The pixel coverage semantic of the resulting image.
  wrapX Is this image wrapped around the X-axis?
returns [not-null] The resulting image.

Remarks:

If this image already has the given pixel coverage semantic, no transformation will be performed.

Validate

Validates the state of this object.

public abstract method Validate (Validator validator)
params validator [not-null] The validator object.
overrides IValidatable.Validate