The Qimage of QT

qimage::qimage ()

Constructs an empty Qimage object, at which point the returned object, if called IsNull, returns a value of True qimage::qimage (const qsize & size, Format format)

Premultiplied, which is the number of bits per pixel to store.

Qimage::format_rgb32	4	The image is stored using a 32-bit RGB format (0xffRRGGBB).
Qimage::format_argb32	5	The image is stored using a 32-bit ARGB format (0xAARRGGBB).

qimage::qimage (int width, int height, format format)

Constructs an image that is width width, height height, formatted format, and returns a null image object if memory allocation fails

qimage::qimage (uchar * data, int width, int height, format format, qimagecleanupfunction cleanupfunction = 0, void *cleanupinfo = 0)

Constructs an image object based on existing data

qimage:: Qimage(uchar * data, int width, int height, int bytesperline, Format Format, qimagecleanupfunction cleanupfunction = 0, void * cleanupinfo = 0)

Constructs an object based on existing data

Where the byteperline algorithm is

(Image width * Image bits/8 bit bit +3 (in order not to lose data))/4 * 4 so that the number of bytes per row is the size of an integer multiple of 4

Bitmap:

The data block portion of a BMP file is not directly stored after a pixel array. In order to ensure that the number of bytes per row is divisible by 4, it is often necessary to add up to 3 bytes of redundant information after each row of data.

X*y size 24-bit BMP image, each pixel accounted for 3 bytes, if x*3 can not be divisible by 4, then each line may be x*3+1, x*3+2 or x*3+3, depending on which value can be divisible by 4.

qimage:: Qimage(const QString & fileName, const char * format = 0)

Constructs an image object from a file

int Qimage::bitplanecount () const

Returns the number of bitmap planes. That is, how many bits make up a pixel, 32,24 8, 1,

uchar * qimage::bits ()

Returns the first address pointing to the image memory int qimage::bytecount () const

Returns the size of the image that is stored int qimage::bytesperline () const

Returns the number of bytes per row of an image

Equivalent to ByteCount ()/height ()

Qrgb qimage::color (int i) const

Returns the RGB value of the I position in the color table int qimage::colorcount () const

Returns the number of colors in a color table

qvector<Qrgb> qimage::colortable () const

Returns the color table qimage qimage::converttoformat (format format, qt::i Mageconversionflags flags = qt::autocolor) const

Convert image format

qimage qimage::copy (const qrect & rectangle = qrect ()) const

Qimage object that returns the size of a sub-region of an image

Qimage qimage::copy(int x, int y, int width, int height) const

Ditto

qimage qimage::createalphamask (qt::imageconversionflags flags = Qt:: Autocolor) Const

Create a transparent mask for each pixel

Qimage qimage::createmaskfromcolor(qrgb color, qt::maskmode mode = Qt:: Maskincolor) Const

 

int qimage::depth() const

returns how many bits of a pixel are needed to save.

 

Format qimage::format() const

 

returns the format of an image

 

Qimage qimage::fromdata(const uchar * data, int size, const char * format = 0)

constructs an image object from a piece of memory in the specified format qimage qimage::fromdata (const qbytearray & data, const char * format = 0)

 

void Qimage::invertpixels(invertmode mode = Invertrgb)

 

invert pixels bool Qimage::load (const QString & fileName, const char * format = 0)

loads images from a file in the specified format bool Qimage::load (qiodevice * device, const char * format)

 

from one device, load the image

bool Qimage::loadfromdata (const uchar * data, int len, const char * format = 0) /c2>

 

loads an image from a specified piece of memory Qrgb qimage::p ixel (const qpoint & position) const

returns the pixel of a point

bool Qimage::save (const QString & fileName, const char * format = 0, int quality =-1) const

Save to file

 

bool Qimage::save (qiodevice * device, const char * format = 0, int quality =-1) const

 

saved to a device.