CWinImg Class Reference

Provides image manipulation, JPEG, PNG, BMP, WMF, EMF, etc... More...

#include <WinImg.h>

Collaboration diagram for CWinImg:


Public Member Functions
BOOL	OpenUserImage (HWND hOwner=NULL, LPCTSTR pTitle="Open Image", LPCTSTR pDefaultExt="jpg")
	Opens a user specified image.
BOOL	SaveUserImage (HWND hOwner=NULL, LPCTSTR pFile=NULL, LPCTSTR pTitle="Open Image", LPCTSTR pDefaultExt="jpg")
	Save image to user specified file.
BOOL	GetUserImage (LPSTR pFile, HWND hOwner=NULL, BOOL bOpen=TRUE, LPCTSTR pTitle="Open Image", LPCTSTR pDefaultExt="jpg")
	Opens a user image.
DWORD	GetImageSize ()
	Returns the size, in bytes, of the raw image buffer.
DWORD	Encode (LPBYTE pBuf, DWORD dwSize, LPCTSTR pType)
	Encodes the specified file to a buffer.
BOOL	Tile (HDC hDC, LPRECT pRect)
	Tiles the image into the specified device context.
BOOL	AlphaDelete ()
	Deletes the alpha layer.
BOOL	HasAlpha ()
	Returns non-zero if the image has an alpha layer.
BOOL	ToClipboard (HWND hWnd)
	Copies the image to the clipboard.
BOOL	FromClipboard (HWND hWnd)
	Grabs an image from the clipboard.
BOOL	DecreaseBpp (DWORD bpp, bool bErrorDiffusion, RGBQUAD *ppal=NULL)
	Decreases the bits per pixel used to represent the image.
BOOL	IncreaseBpp (DWORD bpp)
	Increases the bits per pixel used to represent the image.
BYTE	GetNearestIndex (RGBQUAD rgb)
	Gets the nearest value from the palette to the specified color.
BOOL	SetTransIndex (long index)
	Set the palette index of the transparent color.
long	GetTransIndex ()
	Returns the palette index of the transparent color.
BOOL	SetPixel (long x, long y, RGBQUAD rgb)
	Sets the specified pixel color value.
BOOL	SetPixel (long x, long y, COLORREF rgb)
	Sets the specified pixel color value.
RGBQUAD	GetPixel (long x, long y)
	Returns the color of the specified pixel.
COLORREF	GetRgbPixel (long x, long y)
	Returns the color of the specified pixel.
DWORD	GetBpp ()
	Returns the number of bits per pixel used to represent the image.
RGBQUAD	GetTransColor ()
	Returns the RGB value of the current transparent color.
BOOL	SetTransColor (RGBQUAD rgb)
	Sets the transparent color.
BOOL	IsTransparent ()
	Returns non-zero if transparency is enabled.
BOOL	Resample (LPRECT pRect, int fast=1)
	Resamples the image to the new size.
BOOL	Copy (CWinImg *pImg)
	Copies the specified image.
BOOL	Create (long w, long h, long bpp=24)
	Creates an image of the specified size and color depth.
DWORD	GetEffWidth ()
	Returns the scan width of a row of image data.
LPBYTE	GetBits ()
	Returns a pointer to the raw image buffer.
BOOL	LoadFromResource (LPCTSTR pResource, LPCTSTR pResType, LPCTSTR pImgType, HMODULE hModule=NULL)
	Loads an image from a resource.
long	Histogram (long red, long green=0, long blue=0, long gray=0, long colorspace=0)
	Generates a historgram for the current image.
BOOL	Dilate (long Ksize=2)
	Dialates the image.
BOOL	Erode (long Ksize=2)
	Erodes the image.
BOOL	Light (long level, long contrast=100)
	Lightens the image.
BOOL	Colorize (BYTE hue, BYTE sat)
	Colorizes the image.
BOOL	Threshold (BYTE level)
	Thresholds the image.
BOOL	ShiftRGB (long r, long g, long b)
	Changes the RGB component levels.
BOOL	Gamma (float gamma)
	Gamma correction effect.
BOOL	Median (long Ksize=3)
	Median image effect.
BOOL	Noise (long level)
	Adds noise to the image.
BOOL	Crop (long left, long top, long right, long bottom, CWinImg *pDst=NULL)
	Crops an area of the image.
BOOL	Dither (long method=0)
	Dithers the image.
BOOL	Resample (long newx, long newy, int fast=1)
	Resamples the image.
BOOL	Rotate (float angle, CWinImg *pDst=NULL)
	Rotates the image by the specified ammount.
BOOL	Negative ()
	Generates negative for image.
BOOL	GrayScale ()
	Converts image to gray scale.
BOOL	Flip ()
	Flips the current image vertically.
BOOL	Mirror ()
	Mirrors image horizontally.
HICON	CreateIcon (long w, long h, COLORREF bck=RGB(255, 255, 255), HDC hDC=NULL)
	Creates an icon from the image.
BOOL	SetQuality (DWORD q)
	Sets the quality level for the JPEG encoder.
BOOL	CreateFromHBITMAP (HBITMAP hBmp)
	Creates an image from an HBITMAP handle.
BOOL	IsValid ()
	Returns non-zero if there is a valid image.
long	GetHeight ()
	Returns the image height.
long	GetWidth ()
	Returns the image width.
BOOL	Draw (HDC hDC, LPRECT pRect, BOOL bStretch=TRUE)
	Draws the image to the specified device context.
LPCTSTR	GetLastError ()
	Returns a string pointer describing the last error.
BOOL	Decode (LPBYTE buf, DWORD size, LPCTSTR pType=NULL)
	Decodes an image from a memory buffer.
void	ReleaseEncodeMemory ()
	Releases temporary memory used by CxImage when encoding an image to memory.
BOOL	InitEncodeJpg (long lWidth, long lHeight, long lQuality)
DWORD	EncodeJpg (LPBYTE pSrc, long lWidth, long lHeight, LPBYTE pDst, DWORD dwDst, long lQuality)
	Encodes the specified image buffer as a JPEG in memory.
void	ReleaseEncodeJpg ()
	Releases memory allocated by InitEncodeJpg().
BOOL	Save (LPCTSTR pFile, LPCTSTR pType=NULL)
	Saves encoded image to disk.
BOOL	Load (LPCTSTR pFile, LPCTSTR pType=NULL)
	Loads the specified file from disk.
void	Destroy ()
	Releases the image and all associated resources.
	CWinImg ()
	Default constructor.
virtual	~CWinImg ()
	Destructor.
LPCTSTR	GetFileName ()
	Returns the current image filename if available.
void	SetTransparency (BOOL b)
	Enables / disables transparency.
BOOL	GetTransparency ()
	Returns non-zero if transparency is enabled.
void	SetTransparentColor (COLORREF rgb)
	Sets the transparent color.
COLORREF	GetTransparentColor ()
	Returns the transparent color value.
	operator LPRECT ()
	Returns the size and position of the image.
LPRECT	GetRect ()
	Returns the size and position of the image.
LPBYTE	GetEncBuffer ()
	Returns a pointer to the internal encoded image buffer.
long	GetEncBufferSize ()
	Returns the size of the internal encoded image buffer.
HBITMAP	CreateHBITMAP (HDC hDC=NULL)
	Creates HBITMAP handle from the current image.
	operator HBITMAP ()
	Creates HBITMAP handle from the current image.
LPBYTE	SwapRB (LPBYTE pBuf, UINT uLen)
	Swaps the specified buffer values from RGB to BGR or vice versa.
Static Public Member Functions
static DWORD	GetFileType (LPCTSTR pFile)
	Examines the file extension and returns the image type code.

Detailed Description

Provides image manipulation, JPEG, PNG, BMP, WMF, EMF, etc...

Provides image encoding/decoding for JPEG, PNG, BMP, WMF, EMF, etc... This functionality is primarily achieved by encapsulating the CxImage implementation. You will need to download the CxImage library from http://www.xdp.it/cximage.htm. Many thanks to Davide Pizzolato for providing this library free of charge. If you get the chance, please stop in and give Davide a million dollars.

Member Function Documentation

BOOL CWinImg::Colorize ( BYTE hue,

BYTE sat

)

Colorizes the image.

Parameters:

[in] hue - Hue

[in] sat - Saturation

Returns:
Non-zero if success

See also:

BOOL CWinImg::Copy ( CWinImg * pImg )

Copies the specified image.

Parameters:

[in] pImg - Source image to copy

Returns:
Non-zero if success

See also:

BOOL CWinImg::Create ( long w,

long h,

long bpp = 24

)

Creates an image of the specified size and color depth.

Parameters:

[in] w - Width of new image

[in] h - Height of new image

[in] bpp - Color depth of new image in bits per pixel

Returns:
Non-zero if success

See also:

BOOL CWinImg::CreateFromHBITMAP ( HBITMAP hBmp )

Creates an image from an HBITMAP handle.

Parameters:

[in] hBmp - HBITMAP handle

Returns:
Non-zero if success

See also:

HBITMAP CWinImg::CreateHBITMAP ( HDC hDC = NULL )

Creates HBITMAP handle from the current image.
You must pass the handle to DeleteObject() when it is no longer needed.

Returns:
Handle to bitmap or NULL if error.

See also:

HICON CWinImg::CreateIcon ( long w,

long h,

COLORREF bck = RGB(255, 255, 255),

HDC hDC = NULL

)

Creates an icon from the image.

Parameters:

[in] w - New icon width

[in] h - New icon height

[in] bck - Transparent color used to generate mask.

[in] hDC - Reference device context, NULL to use the desktop.

Returns:
Handle to new icon or NULL if failure

See also:

BOOL CWinImg::Crop ( long left,

long top,

long right,

long bottom,

CWinImg * pDst = NULL

)

Crops an area of the image.

Parameters:

[in] left - Horizontal offset of upper left corner

[in] top - Vertical offset of upper left corner

[in] right - Horizontal offset of lower right corner

[in] bottom - Vertical offset of lower right corner

[in] pDst - CWinDc object that receives the cropped image. NULL to replace current image.

Returns:
Non-zero if success

See also:

BOOL CWinImg::Decode ( LPBYTE buf,

DWORD size,

LPCTSTR pType = NULL

)

Decodes an image from a memory buffer.

Parameters:

[in] buf - Pointer to buffer containing the compressed image.

[in] size - Number of bytes in buf.

[in] pType - Image type, "jpg", "png", etc...

Returns:
Non-zero if success

See also:

BOOL CWinImg::DecreaseBpp ( DWORD bpp,

bool bErrorDiffusion,

RGBQUAD * ppal = NULL

)

Decreases the bits per pixel used to represent the image.

Parameters:

[in] bpp - Desired bits per pixel

[in] bErrorDiffusion - Non-zero to enable error diffusion.

[in] ppal - Optional palette to use.

Returns:
Non-zero if success

See also:

BOOL CWinImg::Dilate ( long Ksize = 2 )

Dialates the image.

Parameters:

[in] Ksize - Dialation weight

Returns:
Non-zero if success

See also:

BOOL CWinImg::Dither ( long method = 0 )

Dithers the image.

Parameters:

[in] method - Dither method ( 0, 1 )

Returns:
Non-zero if success

See also:

BOOL CWinImg::Draw ( HDC hDC,

LPRECT pRect,

BOOL bStretch = TRUE

)

Draws the image to the specified device context.

Parameters:

[in] hDC - Handle to device context

[in] pRect - Destination rectangle for image

[in] bStretch - Non-zero to stretch to pRect

Returns:
Non-zero if success

See also:

DWORD CWinImg::Encode ( LPBYTE pBuf,

DWORD dwSize,

LPCTSTR pType

)

Encodes the specified file to a buffer.

Parameters:

[in] pBuf - Pointer to buffer that receives the encoded image

[in] dwSize - Size of the buffer in pBuf

[in] pType - File extension specifying type of encoding. "jpg", "png", etc...

pBuf must be large enough to hold the encoded image.

Returns:
Number of bytes written to pBuf

See also:

DWORD CWinImg::EncodeJpg ( LPBYTE pSrc,

long lWidth,

long lHeight,

LPBYTE pDst,

DWORD dwDst,

long lQuality

)

Encodes the specified image buffer as a JPEG in memory.

Parameters:

[in] pSrc - Uncompressed source image

[in] lWidth - Width of image

[in] lHeight - Height of image

[in] pDst - Receives JPEG image

[in] dwDst - Size of buffer in pDst

[in] lQuality - JPEG image quality

I couldn't figure out a way to use CxImage to encode a buffer in memory without a memcpy and didn't want to have to depend on a modified library. So this function does not use CxImage to encode.
The image in pSrc must be 24-bit BGR encoded. Scan lines must be DWORD aligned, but that's typical.
The buffer in pDst must be large enough to hold the image or the function fails returning zero. So it is not possible to figure out the required buffer size before calling. I would just make the image at least as large as the image buffer.
This function also reuses the same JPEG compression structures if subsequent calls are made with the same size image

Returns:
Number of bytes written to pDst, or zero if failure.

See also:
InitEncodeJpg(), ReleaseEncodeJpg()

BOOL CWinImg::Erode ( long Ksize = 2 )

Erodes the image.

Parameters:

[in] Ksize - Erosion weight

Returns:
Non-zero if success

See also:

BOOL CWinImg::Flip ( )

Flips the current image vertically.

Returns:
Non-zero if success

BOOL CWinImg::FromClipboard ( HWND hWnd )

Grabs an image from the clipboard.

Parameters:

[in] hWnd - Non-zero if success

Returns:
Non-zero if success

See also:

BOOL CWinImg::Gamma ( float gamma )

Gamma correction effect.

Parameters:

[in] gamma - Gamma correction value

Returns:
Non-zero if success

See also:

LPBYTE CWinImg::GetEncBuffer ( ) [inline]

Returns a pointer to the internal encoded image buffer.
This buffer is only valid after a call to Encode()

Returns:
Pointer to the internal encoded image buffer

See also:

long CWinImg::GetEncBufferSize ( ) [inline]

Returns the size of the internal encoded image buffer.
This buffer is only valid after a call to Encode()

Returns:
Size of the internal encoded image buffer

See also:

DWORD CWinImg::GetFileType ( LPCTSTR pFile ) [static]

Examines the file extension and returns the image type code.

Parameters:

[in] pFile - Filename to examine

Returns:
Image type code

See also:

BYTE CWinImg::GetNearestIndex ( RGBQUAD rgb )

Gets the nearest value from the palette to the specified color.

Parameters:

[in] rgb - Color value

Returns:
Returns the palette index of the nearest color

See also:

RGBQUAD CWinImg::GetPixel ( long x,

long y

)

Returns the color of the specified pixel.

Parameters:

[in] x - Horizontal offset of pixel

[in] y - Vertical offset of pixel

Returns:
Color value of pixel

See also:

COLORREF CWinImg::GetRgbPixel ( long x,

long y

) [inline]

Returns the color of the specified pixel.

Parameters:

[in] x - Horizontal offset of pixel

[in] y - Vertical offset of pixel

Returns:
Color value of pixel

See also:

BOOL CWinImg::GetUserImage ( LPSTR pFile,

HWND hOwner = NULL,

BOOL bOpen = TRUE,

LPCTSTR pTitle = "Open Image",

LPCTSTR pDefaultExt = "jpg"

)

Opens a user image.

Parameters:

[in] pFile - Receives the user filename.

[in] hOwner - Handle to parent window

[in] bOpen - Non-zero for open dialog, zero to display the save dialog.

[in] pTitle - Title of the dialog box

[in] pDefaultExt - Default image extension

Returns:
Number of bytes written to pBuf

See also:

BOOL CWinImg::GrayScale ( )

Converts image to gray scale.

Returns:
Non-zero if success

long CWinImg::Histogram ( long * red,

long * green = 0,

long * blue = 0,

long * gray = 0,

long colorspace = 0

)

Generates a historgram for the current image.

Parameters:

[out] red - Receives the red histogram

[out] green - Receives the green histogram

[out] blue - Receives the blue histogram

[out] gray - Receives the gray scale histogram

[in] colorspace - Colorspace

Returns:
Length of histogram

See also:

BOOL CWinImg::IncreaseBpp ( DWORD bpp )

Increases the bits per pixel used to represent the image.

Parameters:

[in] bpp - Desired bits per pixel

Returns:
Non-zero if success

See also:

BOOL CWinImg::InitEncodeJpg ( long lWidth,

long lHeight,

long lQuality

)

Parameters:

[in] lWidth - Image width

[in] lHeight - Image height

[in] lQuality - JPEG encoding quality

This function is called automatically by EncodeJpg(), so it is not necessary to call this function directly.

Returns:
Non-zero if success

See also:
EncodeJpg(), ReleaseEncodeJpg()

BOOL CWinImg::Light ( long level,

long contrast = 100

)

Lightens the image.

Parameters:

[in] level - Lighten level

[in] contrast - Contrast

Returns:
Non-zero if success

See also:

BOOL CWinImg::Load ( LPCTSTR pFile,

LPCTSTR pType = NULL

)

Loads the specified file from disk.

Parameters:

[in] pFile - Filename

[in] pType - Image type "jpg", "png", etc... If pType is NULL, the image type is determined by examining the file extension in pFile.

Returns:
Non-zero if success

See also:

BOOL CWinImg::LoadFromResource ( LPCTSTR pResource,

LPCTSTR pResType,

LPCTSTR pImgType,

HMODULE hModule = NULL

)

Loads an image from a resource.

Parameters:

[in] pResource - Resource name

[in] pResType - Resource type

[in] pImgType - Image type, "jpg", "png", etc...

[in] hModule - Handle to module containing the image resource

Returns:
Non-zero if success

See also:

BOOL CWinImg::Median ( long Ksize = 3 )

Median image effect.

Parameters:

[in] Ksize - Median image weight

Returns:
Non-zero if success

See also:

BOOL CWinImg::Mirror ( )

Mirrors image horizontally.

Returns:
Non-zero if success

BOOL CWinImg::Negative ( )

Generates negative for image.

Returns:
Non-zero if success

BOOL CWinImg::Noise ( long level )

Adds noise to the image.

Parameters:

[in] level - Noise level

Returns:
Non-zero if success

See also:

BOOL CWinImg::OpenUserImage ( HWND hOwner = NULL,

LPCTSTR pTitle = "Open Image",

LPCTSTR pDefaultExt = "jpg"

)

Opens a user specified image.

Parameters:

[in] hOwner - Handle to parent window

[in] pTitle - Title of the dialog box

[in] pDefaultExt - Default image extension

Returns:
Non-zero if image opened.

See also:

CWinImg::operator HBITMAP ( ) [inline]

Creates HBITMAP handle from the current image.
You must pass the handle to DeleteObject() when it is no longer needed.

Returns:
Handle to bitmap or NULL if error.

See also:

void CWinImg::ReleaseEncodeJpg ( )

Releases memory allocated by InitEncodeJpg().
This function will be called when this CWinDc object is destroyed, so it is not necessary to call this function.

See also:
InitEncodeJpg(), EncodeJpg()

BOOL CWinImg::Resample ( long newx,

long newy,

int fast = 1

)

Resamples the image.

Parameters:

[in] newx - New horizontal image size

[in] newy - New vertical image size

[in] fast - Resampling algorithm to use ( 0, 1 )

Returns:
Non-zero if success

See also:

BOOL CWinImg::Resample ( LPRECT pRect,

int fast = 1

)

Resamples the image to the new size.

Parameters:

[in] pRect - New size for image

[in] fast - Resampling algorithm to use ( 0, 1 )

Returns:
Non-zero if success

See also:

BOOL CWinImg::Rotate ( float angle,

CWinImg * pDst = NULL

)

Rotates the image by the specified ammount.

Parameters:

[in] angle - Rotation angle in degrees

[in] pDst - CWinDc object that receives rotated image. NULL to replace current image.

Returns:
Non-zero if success

See also:

BOOL CWinImg::Save ( LPCTSTR pFile,

LPCTSTR pType = NULL

)

Saves encoded image to disk.

Parameters:

[in] pFile - Filename

[in] pType - Image type "jpg", "png", etc... If pType is NULL, the image type is determined by examining the file extension in pFile.

Returns:
Non-zero if success.

See also:

BOOL CWinImg::SaveUserImage ( HWND hOwner = NULL,

LPCTSTR pFile = NULL,

LPCTSTR pTitle = "Open Image",

LPCTSTR pDefaultExt = "jpg"

)

Save image to user specified file.

Parameters:

[in] hOwner - Handle to parent window

[in] pFile - Initial file name

[in] pTitle - Title of the dialog box

[in] pDefaultExt - Default image extension

Returns:
Non-zero if image saved

See also:

BOOL CWinImg::SetPixel ( long x,

long y,

COLORREF rgb

) [inline]

Sets the specified pixel color value.

Parameters:

[in] x - Horizontal offset of pixel

[in] y - Vertical offset of pixel

[in] rgb - New color value for pixel

Returns:
Non-zero if success

See also:

BOOL CWinImg::SetPixel ( long x,

long y,

RGBQUAD rgb

)

Sets the specified pixel color value.

Parameters:

[in] x - Horizontal offset of pixel

[in] y - Vertical offset of pixel

[in] rgb - New color value for pixel

Returns:
Non-zero if success

See also:

BOOL CWinImg::SetQuality ( DWORD q )

Sets the quality level for the JPEG encoder.

Parameters:

[in] q - JPEG quality level

Returns:
Non-zero if success

See also:

BOOL CWinImg::SetTransColor ( RGBQUAD rgb )

Sets the transparent color.

Parameters:

[in] rgb - Transparent color value

Returns:
Non-zero if success

See also:

BOOL CWinImg::SetTransIndex ( long index )

Set the palette index of the transparent color.

Parameters:

[in] index - Palette index of transparent color

Returns:
Non-zero if success

See also:

void CWinImg::SetTransparency ( BOOL b ) [inline]

Enables / disables transparency.

Parameters:

[in] b - Non-zero to enable transparency. Zero disables transparency.

void CWinImg::SetTransparentColor ( COLORREF rgb ) [inline]

Sets the transparent color.

Parameters:

[in] rgb - Transparent color

BOOL CWinImg::ShiftRGB ( long r,

long g,

long b

)

Changes the RGB component levels.

Parameters:

[in] r - Red component level

[in] g - Green component level

[in] b - Blue component level

Returns:
Non-zero if success

See also:

LPBYTE CWinImg::SwapRB ( LPBYTE pBuf,

UINT uLen

) [inline]

Swaps the specified buffer values from RGB to BGR or vice versa.

Parameters:

[in] pBuf - Input color values

[in] uLen - Length of color values

Returns:
The value in pBuf

BOOL CWinImg::Threshold ( BYTE level )

Thresholds the image.

Parameters:

[in] level - Threshold level

Converts the image to a monochrome image, converting all values above the threshold value to white. All values below the threshold are converted to black.

Returns:
Non-zero if success

See also:

BOOL CWinImg::Tile ( HDC hDC,

LPRECT pRect

)

Tiles the image into the specified device context.

Parameters:

[in] hDC - Handle to device context

[in] pRect - Portion of hDC to tile

Returns:
Non-zero if success

See also:

BOOL CWinImg::ToClipboard ( HWND hWnd )

Copies the image to the clipboard.

Parameters:

[in] hWnd - Window handle

Returns:
Non-zero if success

See also:

The documentation for this class was generated from the following files:

inc/WinImg.h
WinImg.cpp

CWinImg Class Reference

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation