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<concept id="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF" xml:lang="en"><title>Adding

Effects And Filters Guide</title><prolog><metadata><keywords/></metadata></prolog><conbody>

<p>This document gives you more information about the image effects and filters. </p>

<section><title>Purpose</title> <p>The purpose of this guide is to show you

how to implement different image effects and filters using Image Processor. </p> <p><b>Introduction</b> </p> <p>Adding effects to an image with Image Processor

is very simple. </p> <p>Effects are applied in the order they are inserted

in a image. <b>Note:</b> The result from rendering an image can be different

depending on the order the effects are applied to an image. </p> <p>The code

example below shows an implementation in the order: crop, mirror, and 90 degree

rotation. </p> <codeblock id="GUID-041412C5-BD03-56C2-A5A8-162C5058A243" xml:space="preserve">

// Get TInputInfo interface

TInputInfo* inputInfo = imageProcessor->InputInfoL();

// Get the input image size

TSize inputSize = inputInfo->SizeL();

// Define crop region

TRect cropRegion(inputSize.iWidth / 4, inputSize.iHeight / 4, inputSize.iWidth / 2, inputSize.iHeight /2);

// Apply crop

imageProcessor->SetInputRectL(cropRegion);

// Get TEffect interface for Mirror Left To Right effect. 

// Note. All effects can be handled via generic TEffect interface. For more advanced functionality

// the interface pointer must be cast to a derived effect interfece.

TEffect* effect = imageProcessor->EffectL(KEffectMirrorLeftToRightUid);

// Standard sequence of function calls to apply any effect. 

// The effect must be started with BeginL() and finished with EndL() functions calls.

effect->BeginL();

effect->EndL();

// As non-standard effect geometrical operation can be used via derived interface only.

TGeometricalOperation* operation = static_cast<TGeometricalOperation*>(imageProcessor->EffectL(KGeometricalOperationUid));

operation->BeginL();

operation->SetOperationL(ImageProcessor::CImgProcessor::EOperationRotate270);

operation->EndL();

</codeblock> </section>

<section><title>Undo</title> <p>Image Processor has a built-in undo mechanism,

which removes the last added effect or operation on the undo stack. Parameter

changes are not added to the undo stack. There is an unlimited number of undo

steps and you can check if an undo operation is possible. </p> <p>The code

example below shows the implementation the <codeph>ImageProcessor::CImageProcessor::UndoL()</codeph> function: </p> <codeblock id="GUID-80FD0739-851C-57F8-AEF0-4BB6B8634355" xml:space="preserve">

TEffectRotation* rotationEffect = static_cast<TEffectRotation*>(imageProcessor->EffectL(KEffectRotationUid));

rotationEffect->BeginL();

rotationEffect->SetRotationL(ImageProcessor::TEffectRotation::ERotationScaleModeFitInside, 45.0f);

rotationEffect->EndL();

// Check if we can undo last applied effect

if (imageProcessor->CanUndoL()) 

{

    // Undo the effect

    imageProcessor->UndoL();

}

</codeblock> </section>

<section><title>Adjustable generic effects </title> <p>Those imaging effects

that have variable strengths or settings to choose from are called adjustable

generic effects. These effects each have three related functions: </p> <ul>

<li id="GUID-51F7D507-5788-5120-AC0B-9E599FEE66A2"><p>The <xref href="GUID-5DD1A7CA-B0F8-3769-9D53-4541BDC2C3FB.dita#GUID-5DD1A7CA-B0F8-3769-9D53-4541BDC2C3FB/GUID-406C6996-EEA8-3404-B0EF-3FC2EDC021D2"><apiname>ImageProcessor::TEffect::BeginL()</apiname></xref> function

is used to initiate the adjustable generic effect. </p> <p>Any function calls

from Image Processor operations are disabled until the <codeph>EndL()</codeph> function

is called. For example when you try to apply another effect, this cause a

leave <codeph>KErrNotReady</codeph>. </p> <p>For example, if you want to invoke

an <codeph>UndoL()</codeph> call, Image Processor operations are blocked between <codeph>BeginL()</codeph> and

thecorresponding <codeph>EndL()</codeph> call. An UndoL() call can be invoked

after an <codeph>EndL()</codeph> call. This will cancel the effects applied

between the last <codeph>BeginL()</codeph> and <codeph>EndL()</codeph> calls. </p> </li>

<li id="GUID-A194B271-CE29-54F1-BFD6-134CE9CC8923"><p>The <xref href="GUID-5DD1A7CA-B0F8-3769-9D53-4541BDC2C3FB.dita#GUID-5DD1A7CA-B0F8-3769-9D53-4541BDC2C3FB/GUID-1588C652-4105-366D-82EF-74EB582D2339"><apiname>ImageProcessor::TEffect::SetLevelL()</apiname></xref> function

is used to set the parameters of the current adjustable effect. </p> <p>For

example, when you want to change the parameters of the effect, you must call

the <codeph>ImageProcessor::TEffect::SetLevelL()</codeph> function to set

the parameters of the current adjustable effect. </p> </li>

<li id="GUID-AB2A6C70-8AAA-5916-BEE2-682EBC260E49"><p>The <xref href="GUID-5DD1A7CA-B0F8-3769-9D53-4541BDC2C3FB.dita#GUID-5DD1A7CA-B0F8-3769-9D53-4541BDC2C3FB/GUID-C0A7EEA7-A5B3-3441-8148-29B2B306CB81"><apiname>ImageProcessor::TEffect::EndL()</apiname></xref> function

is used to end the current adjustable effect. </p> <p>For example, when you

are satisfied with the result of the effect, you must call <codeph>ImageProcessor::TEffect::EndL()</codeph> to

complete the current adjustable effect. </p> <p> <b>Note:</b> If you are not

satisfied with the result of the effect, you must call the <codeph>EndL()</codeph> function

of the current generic effect followed by a call to the <codeph>UndoL()</codeph> function. </p> </li>

</ul> <p>The code example below shows how to use an adjustable begin-end effect: </p> <codeblock id="GUID-7B09C5D7-D48D-550E-8116-5CB6811BF1A6" xml:space="preserve">

// Get sharpness effect

TEffect* effect=imageProcessor->EffectL(KEffectSharpnessUid);

// Apply default level of Sharpness

effect->BeginL();

effect->EndL();

</codeblock> </section>

<section><title>Working with preview </title> <p>Most mobile imaging applications

render full-resolution images twice: </p> <ol id="GUID-61808DC4-7C6F-5371-BFD2-AB7275EF9717">

<li id="GUID-F11B0934-3D84-5F3A-88C7-C38A25CDA2F4"><p>for a preview on the

screen </p> </li>

<li id="GUID-23DA4BE1-B256-5B39-BE6C-E97232EF8BA0"><p>for the rendering of

the output image. </p> </li>

</ol> <p>To make the render operation into a simple function, you must call

the <xref href="GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7.dita#GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7/GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495"><apiname>ImageProcessor::TPreview</apiname></xref> function. </p> <p>The <xref href="GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7.dita#GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7/GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495"><apiname>ImageProcessor::TPreview</apiname></xref> function

is an interface that describes the preview identified by the preview ID. The

interface is initialized by specifying an output Symbian bitmap or pixel buffer

(image frame) by calling <xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-38670F92-962C-31D5-9642-9F3F9BE42B30"><apiname>ImageProcessor::TPreview::SetOutput()</apiname></xref>. </p> <p>You

can use the preview for the zoom and pan effects: </p> <codeblock id="GUID-862C5EB5-4E2C-51E2-AF8E-65F6C5785B3B" xml:space="preserve">

void TPreview::SetZoomL(TReal32 aZoom);

void TPreview::SetPanL(TReal32 aPanX, TReal32 aPanY);

TReal32 TPreview::ZoomL() const;

void TPreview::PanL(TReal32& aPanX, TReal32& aPanY) const;

</codeblock> <p>The <codeph>TReal32</codeph> of pan effect ranges from -1.0

to 1.0 and the <codeph>TReal32</codeph> of zoom effect ranges from 1.0x to <codeph>TReal32</codeph> maximum

value. </p> <p> <b>Note:</b> The zoom and pan effects only affect the preview.

When rendering the original image, these changes are ignored. </p> </section>

<section><title>Changing the input </title> <p>The source image can be changed

by calling the <xref href="GUID-13E30312-DD05-3581-9A59-C3569A981657.dita#GUID-13E30312-DD05-3581-9A59-C3569A981657/GUID-0448A658-7DD6-3767-82FC-1EE64B1CBEE3"><apiname>ImageProcessor::CImgProcessor::SetInputL()</apiname></xref> function

without creating a new Image Processor instance. <codeph>ImageProcessor::CImgProcessor::SetInputL()</codeph> can

be used when displaying thumbnails or when choosing between different overlay

graphics. The image source can freely be switched between file, buffer, bitmap

and a background colour. </p> <p>The code example below illustrates the chain

of effects applied to a number of images and rendered to screen. </p> <codeblock id="GUID-2D54E9BB-20FE-5F02-A00E-71AAD089FBF0" xml:space="preserve">

    // Get white balance effect

    effect = imageProcessor->EffectL(KEffectWhiteBalanceUid);

    // Apply default white balance 

    effect->BeginL();

    effect->EndL();

    // Go through the images and render the preview for each of them

    for (TInt i = 0; i < 4; i++) 

        {

        imageProcessor->SetInputL(*filenames[i]);

        preview->RenderL();

  }

</codeblock> </section>

<section><title>Image information </title> <p>Image Processor has functionality

to get information about the source image. This information can be used for

display in a file browser or to verify the correct capabilities that are available

for a specific processing task. </p> <p>First, a pointer to <xref href="GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7.dita#GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7/GUID-E1B6400E-1A36-368A-AAC7-CDDE3ED656A2"><apiname>ImageProcessor::TInputInfo()</apiname></xref> interface

must be obtained from the active Image Processor instance. To extract the

information, the following functions are called: </p> <codeblock id="GUID-C940E27B-4FCE-5C9A-B39A-4C04C9BD6591" xml:space="preserve">

TSize TInputInfo::SizeL() const; 

void TInputInfo::FormatL(TUid& aFormat, TUid& aSubFormat) const;

TDisplayMode TInputInfo::DisplayModeL() const; 

TUid TInputInfo::ImageFrameFormatL() const; 

TUid TInputInfo::SamplingL() const; 

TUint32 TInputInfo::BitsPerPixelL() const; 

TBool TInputInfo::IsProgressiveL() const; 

TBool TInputInfo::IsInterlacedL() const; 

TBool TInputInfo::HasAlphaL() const;

</codeblock> </section>

<section><title>Coordinates and areas </title> <p>Image Processor uses a number

of different coordinate systems to cope with the translation from the preview

image to the input image. </p> <p>In this section the following concepts are

introduced: </p> <ul>

<li id="GUID-B9B0ED22-9EAC-50B3-9987-6BDE1C2D5513"><p><xref href="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF.dita#GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF/GUID-4CB4BD23-85CD-5239-96C4-936BC46EE745"> Input images</xref>  </p> </li>

<li id="GUID-4E83AAF6-9820-5D28-9B7B-38E8F4F709DD"><p><xref href="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF.dita#GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF/GUID-F956698F-28B3-5CFB-9ABC-E4C69688B284"> Geometry and orientation effects</xref>  </p> </li>

<li id="GUID-07F10586-079D-58BA-9B6D-B9A00372BAF2"><p><xref href="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF.dita#GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF/GUID-43A6D850-367B-5A57-8CAA-03113298ED07"> Previews</xref>  </p> </li>

<li id="GUID-367CA050-A363-5D93-B99E-711B180EAA7C"><p><xref href="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF.dita#GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF/GUID-BB35B339-CFB6-54CB-9D20-308EEB82225F">Preview canvases</xref>  </p> </li>

<li id="GUID-F59E4119-8111-51BF-98EA-799E52DC870E"><p><xref href="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF.dita#GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF/GUID-1187E33F-1EA4-57A0-BC12-1810A48CF61B">Zoom and pan settings</xref>  </p> </li>

<li id="GUID-C14A7AFA-6F20-5313-99CA-7887D5A3895F"><p><xref href="GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF.dita#GUID-F221B15F-B5DE-516F-8FB0-75C1971DB3AF/GUID-7DA27E76-C144-5784-9748-2839766B9A52">Overlay images</xref>  </p> </li>

</ul> <p id="GUID-4CB4BD23-85CD-5239-96C4-936BC46EE745"><b>Input images</b> </p> <p>A

coordinate system is the region within which a given set of coordinates are

relevant. In many scenarios, you will need to provide coordinate information

to Image Processor. This information is ambiguous without additional handling

to make the coordinates apply to a specific coordinate system. </p> <p>An

area defines the dimensions of a region. Image data can change form and scale

during the editing session, which means that a set of areas with different

dimensions can exist throughout the chain of operations. </p> <p>All imaging

sessions use a source image as a base. The source image represents the source

coordinate system and the source area. The source coordinate system is not

public since it has no relevance to the user. The source coordinate system

starts at the top left corner of the source image and expands downwards along

the y-axis and to the right along the x-axis. The source area size is public,

however, and can be queried through the <xref href="GUID-13E30312-DD05-3581-9A59-C3569A981657.dita#GUID-13E30312-DD05-3581-9A59-C3569A981657/GUID-1D0573C2-611F-3527-9C0B-8E668A208133"><apiname>ImageProcessor::CImgProcessor::CurrentSizeL() </apiname></xref> function. </p> <p id="GUID-F956698F-28B3-5CFB-9ABC-E4C69688B284"><b>Geometry and orientation

effects</b> </p> <p>Applying geometry effects and orientation effects to an

input image is usually a chain process. When all effects have been applied,

the resulting image may differ in geometry from the original source image.

Hence, the resulting image defines a new area called the current area and

a new coordinate system called the current coordinate system. Both of these

are public and can be queried through the Image Processor. The current coordinate

system starts at the top left corner of the image and expands downwards along

the y-axis and to the right along the x-axis. </p> <p id="GUID-43A6D850-367B-5A57-8CAA-03113298ED07"><b>Previews</b> </p> <p>You

can make use of one or more previews when processing an image. A preview defines

the region on which the image is shown. A preview introduces the preview area

and the preview coordinate system, both of which are public. The preview coordinate

system starts at the top left corner of the screen and expands downwards along

y-axis and to the right along x-axis. </p> <p>Use <xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-AF30A4A2-736E-3256-8C14-31368F0A24E3"><apiname>ImageProcessor::TPreview::PreviewToCurrentCoordL()</apiname></xref> to

perform coordinate conversion and <xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-CB6994A3-4355-3D67-85BB-8690F37EE0DD"><apiname>ImageProcessor::TPreview::SizeL()</apiname></xref> to

get the size of the preview area. </p> <p>To convert between preview coordinates

and current coordinates use the <xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-C38A0CD8-061F-383F-9C0F-06E153FAD477"><apiname>ImageProcessor::TPreview::PreviewToCurrentCoordL(const

             TPoint&amp;)</apiname></xref> function. To convert between canvas coordinates

to current coordinates use the <xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-481BCBAC-20B9-3134-A20B-EEEFE92C1C22"><apiname>ImageProcessor::TPreview::CanvasToCurrentCoordL()</apiname></xref> function. </p> <p>It

can be useful to know the current size of the session image, that is, the

size of the image after any effects and cropping have been applied, by using

the <xref href="GUID-13E30312-DD05-3581-9A59-C3569A981657.dita#GUID-13E30312-DD05-3581-9A59-C3569A981657/GUID-1D0573C2-611F-3527-9C0B-8E668A208133"><apiname>ImageProcessor::CImgProcessor::CurrentSizeL()</apiname></xref> function. </p> <p id="GUID-BB35B339-CFB6-54CB-9D20-308EEB82225F"><b>Preview canvases</b> </p> <p>Each

preview contains a sub-region called the canvas. When the resulting image

is scaled to fit the preview area, while preserving aspect ratio, the actual

image data will not cover the entire screen and the areas outside the image

are filled with a background colour. The area containing the image data is

always referred to as the canvas. A canvas introduces the canvas area and

the canvas coordinate system, both of which are public. The canvas coordinate

system starts at the top left corner of the canvas and expands downwards along

the y-axis and to the right along the x-axis. </p> <p>Use the <xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-481BCBAC-20B9-3134-A20B-EEEFE92C1C22"><apiname>ImageProcessor::TPreview::CanvasToCurrentCoordL()</apiname></xref> to

perform coordinate conversion and<xref href="GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495.dita#GUID-9CBD93A5-1916-31C4-A974-213FCD7A5495/GUID-A69588CB-8BF2-3FA9-806A-216CA460E912"><apiname>ImageProcessor::TPreview::CanvasAreaL()</apiname></xref> function

to return the size and location of the canvas area. </p> <p id="GUID-1187E33F-1EA4-57A0-BC12-1810A48CF61B"><b> Zoom and Pan settings</b> </p> <p>Zoom

and Pan settings do not introduce their own areas or coordinate systems. In

this regard, Zoom and pan are equivalent to a preview. </p> <p id="GUID-7DA27E76-C144-5784-9748-2839766B9A52"><b>Overlay images</b> </p> <p>Overlay

images define their own overlay coordinate system and overlay area. The coordinate

system of an overlay image is public. The overlay coordinate system and overlay

are rarely used since they are not treated as separate objects once they are

applied to the source image. The overlay is treated as part of the original

image data after insertion. </p> <p>However, the coordinate system of an overlay

image is relevant for defining its anchor point to the source image. The overlay

area can be queried from Image Processor instances that expose overlay operations.

The overlay coordinate system starts at the centre of the overlay image and

expands to the left along the negative side of the y-axis, upwards along the

negative side of the x-axis, to the right along the x-axis and downwards along

the y-axis. </p> </section>

<section><title>Applying overlay and border effects</title> <p>It is possible

to add borders (frames) and overlays to your input image. For example, you

might want to add a logo to an image or add a pair of sunglasses to a picture.

To use a border effect, call <xref href="GUID-13E30312-DD05-3581-9A59-C3569A981657.dita#GUID-13E30312-DD05-3581-9A59-C3569A981657/GUID-EF0B943B-C58D-39AD-AAA3-ABEE11033A8C"><apiname>ImageProcessor::CImgProcessor::EffectL(KEffectBorderUid)</apiname></xref>. </p> <p>Border

images are images with alpha channels. The border is automatically stretched

to fit the input image. </p> <p>To use overlay effect, call <xref href="GUID-13E30312-DD05-3581-9A59-C3569A981657.dita#GUID-13E30312-DD05-3581-9A59-C3569A981657/GUID-08855134-3A4C-3BE5-B817-73342FFD5CCE"><apiname>ImageProcessor::CImgProcessor::OverlayL()</apiname></xref>. </p> <p>There

are two ways to insert an overlay to an image, either from a file or from

memory. If you load the overlay from a file, both PNG and JPEG are accepted,

but you will only have the transparency option if you use a PNG image. The

overlay is managed through the interface <xref href="GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7.dita#GUID-9E5136D1-B8BE-3CE4-9A20-39D672E31EC7/GUID-95D515E0-F751-3703-8FD1-80F9B8870E16"><apiname>ImageProcessor::TOverlay</apiname></xref>. </p> <p>You

can specify the position, the scale, and the angle of the overlay. The position

must be given in current coordinates. The scale ranges from 0.0 to infinity,

where 1.0 represent no scaling. The angle ranges from 0.0 degrees to 360.0

degrees. To begin inserting the overlay the <xref href="GUID-95D515E0-F751-3703-8FD1-80F9B8870E16.dita#GUID-95D515E0-F751-3703-8FD1-80F9B8870E16/GUID-E1255D4A-714D-31A8-9E5E-CCBFF477E2F4"><apiname>ImageProcessor::TOverlay::BeginL()</apiname></xref> function

must be called. The code example below illustrates the scale effect and the

angle of the overlay effect. </p> <p>When the overlay is in place you must

call <xref href="GUID-95D515E0-F751-3703-8FD1-80F9B8870E16.dita#GUID-95D515E0-F751-3703-8FD1-80F9B8870E16/GUID-B3250D2E-CBCB-357C-82CA-7A7B35045CAE"><apiname>ImageProcessor::TOverlay::EndL()</apiname></xref> to conclude the overlay. </p> <p>The

code examples below describe some common scenarios: </p> <ul>

<li id="GUID-A2AA2186-067D-571C-AC58-14E97050ED49"><p>You want to insert an

overlay image in the centre of the image you see on the screen. The scale

is set to 1.0 and the angle is set to 0 degrees. It is crucial to distinguish

between canvas coordinates and current coordinates. </p> </li>

<li id="GUID-24318F41-42F7-5297-B022-6914FB78B381"><p>After the overlay is

started you want to double its size, rotate it 45 degrees clockwise, and move

it down ten screen pixels. </p> </li>

</ul> <codeblock id="GUID-A558142D-8C96-5DB8-B2AF-277C645BE47D" xml:space="preserve">

    TPoint overlayPosition(0,0);

    // Get preview canvas rectangle 

    TRect canvasArea = preview->CanvasAreaL();

    // Set overlay position to the center of the preview canvas area     

    overlayPosition.iX = (canvasArea.iBr.iX - canvasArea.iTl.iX) / 2;

    overlayPosition.iY = (canvasArea.iBr.iY - canvasArea.iTl.iY) / 2;

    // Convert the preview canvas coordinates to the input current coordinates  

    TPoint tmp(0, 0);

    preview->CanvasToCurrentCoordL(overlayPosition, tmp);

    overlayPosition = tmp;

    // Get TOverlay interface

    TOverlay* overlay = imageProcessor->OverlayL();

    // Begin the overlay with a overlay file

    overlay->SetInputL(KInputOverlayFileName, KImageTypePNGUid);

    overlay->BeginL();

    // Set overlay with 1.0 x/y scale (un-scaled), position at the center of the preview canvas, 0.0 angle (no rotation)

    overlay->SetL(1.0f, 1.0f, overlayPosition, 0.0f);

    // we can check what this looks like by rendering to the preview

    preview->RenderL();

    // We can then double the size of the overlaid, rotate it 45 degrees clockwise 

    // and move it down ten screen pixels.

    TReal32 overlayScaleX = 0.0f;

    TReal32 overlayScaleY = 0.0f;

    overlay->GetScaleL(overlayScaleX, overlayScaleY);

    overlayScaleX *= 2.0f;

    overlayScaleY *= 2.0f;

    TReal32 overlayAngle = overlay->AngleL();

    // Rotate the overlay 45 degrees 

    overlayAngle += 45.0f;

    if (overlayAngle >= 360.0f)

        {

        overlayAngle = overlayAngle - 360.0f;

        }

    // Move down the position of the overlay 10 screen pixels

    overlayPosition = overlay->PositionL();

    overlayPosition.iY += 10;

    // Set overlay with new parameters

    overlay->SetL(overlayScaleX, overlayScaleY, overlayPosition, overlayAngle);

    // Apply overlay parameters and finish with overlay

    overlay->EndL();

    preview->RenderL();

</codeblock> </section>

<example><p/></example>

<section><title>See also</title> <p><xref href="GUID-8E794D5A-9C83-54EB-AD5A-6A74BB155223.dita">JPEG

Image Transform Extension Guide</xref>  </p> </section>