Up

# NSBitmapImageRep.m

### Authors

Adam Fedor (`fedor@gnu.org`)

> Bitmap image representation.

Copyright: (C) 1996 Free Software Foundation, Inc.

### Contents -

1. Class Description
2. Software documentation for the NSBitmapImageRep(GNUstepExtension) category

# Class Description

NSBitmapImageRep is an image representation for handling images composed of pixels. The standard image format for NSBitmapImageRep is the TIFF format. However, through the use of image filters and other methods, many other standard image formats can be handled by NSBitmapImageRep. Images are typically handled through the NSImage class and there is often no need to use the NSBitmapImageRep class directly. However there may be cases where you want to manipulate the image bitmap data directly.

## NSBitmapImageRep : NSImageRep

> Declared in:
>   AppKit/NSBitmapImageRep.h

> Standards:
> - MacOS-X
> - OpenStep
> - GNUstep

Description forthcoming.

Method summary

- +imageRepsWithFile:
- +TIFFRepresentationOfImageRepsInArray:
- +TIFFRepresentationOfImageRepsInArray:usingCompression:factor:
- +getTIFFCompressionTypes:count:
- +imageRepWithData:
- +imageRepsWithData:
- +localizedNameForTIFFCompressionType:
- +representationOfImageRepsInArray:usingType:properties:
- -TIFFRepresentation
- -TIFFRepresentationUsingCompression:factor:
- -bitmapData
- -bitsPerPixel
- -bytesPerPlane
- -bytesPerRow
- -canBeCompressedUsing:
- -colorizeByMappingGray:toColor:blackMapping:whiteMapping:
- -getBitmapDataPlanes:
- -getCompression:factor:
- -initWithBitmapDataPlanes:pixelsWide:pixelsHigh:bitsPerSample:samplesPerPixel:hasAlpha:isPlanar:colorSpaceName:bytesPerRow:bitsPerPixel:
- -initWithBitmapHandle:
- -initWithData:
- -initWithFocusedViewRect:
- -initWithIconHandle:
- -isPlanar
- -numberOfPlanes
- -representationUsingType:properties:
- -samplesPerPixel
- -setCompression:factor:
- -setProperty:withValue:
- -valueForProperty:

### TIFFRepresentationOfImageRepsInArray:

+ (NSData*) TIFFRepresentationOfImageRepsInArray: (NSArray*)anArray;

Produces an NSData object containing a TIFF representation of all the images stored in anArray. BUGS: Currently this only works if the images are NSBitmapImageRep objects, and it only creates an TIFF from the first image in the array.

### TIFFRepresentationOfImageRepsInArray:usingCompression:factor:

+ (NSData*) TIFFRepresentationOfImageRepsInArray: (NSArray*)anArray usingCompression: (NSTIFFCompression)type factor: (float)factor;

Produces an NSData object containing a TIFF representation of all the images stored in anArray. The image is compressed according to the compression type and factor . BUGS: Currently this only works if the images are NSBitmapImageRep objects, and it only creates an TIFF from the first image in the array.

### getTIFFCompressionTypes:count:

+ (void) getTIFFCompressionTypes: (const NSTIFFCompression**)list count: (int*)numTypes;

Description forthcoming.

### imageRepWithData:

+ (id) imageRepWithData: (NSData*)imageData;

Returns a newly allocated NSBitmapImageRep object representing the image stored in imageData. If the image data contains more than one image, the first one is choosen.

### imageRepsWithData:

+ (NSArray*) imageRepsWithData: (NSData*)imageData;

Returns an array containing newly allocated NSBitmapImageRep objects representing the images stored in imageData.

### localizedNameForTIFFCompressionType:

+ (NSString*) localizedNameForTIFFCompressionType: (NSTIFFCompression)type;

Description forthcoming.

### representationOfImageRepsInArray:usingType:properties:

+ (NSData*) representationOfImageRepsInArray: (NSArray*)imageReps usingType: (NSBitmapImageFileType)storageType properties: (NSDictionary*)properties;

Description forthcoming.

### TIFFRepresentation

- (NSData*) TIFFRepresentation;

Returns an NSData object containing a TIFF representation of the receiver.

### TIFFRepresentationUsingCompression:factor:

- (NSData*) TIFFRepresentationUsingCompression: (NSTIFFCompression)type factor: (float)factor;

Returns an NSData object containing a TIFF representation of the receiver. The TIFF data is compressed using compresssion type and factor.

### bitmapData

- (unsigned char*) bitmapData;

Returns the first plane of data representing the image.

### bitsPerPixel

- (int) bitsPerPixel;

Returns the number of bits need to contain one pixels worth of data. This is normally the number of samples per pixel times the number of bits in one sample.

### bytesPerPlane

- (int) bytesPerPlane;

Returns the number of bytes in a plane. This is the number of bytes in a row times tne height of the image.

### bytesPerRow

- (int) bytesPerRow;

Returns the number of bytes in a row. This is typically based on the width of the image and the bits per sample and samples per pixel (if in medhed configuration). However it may differ from this if set explicitly in -initWithBitmapDataPlanes:pixelsWide:pixelsHigh:bitsPerSample:samplesPerPixel:hasAlpha:isPlanar:colorSpaceName:bytesPerRow:bitsPerPixel: .

### canBeCompressedUsing:

- (BOOL) canBeCompressedUsing: (NSTIFFCompression)compression;

Returns `YES` if the receiver can be stored in a representation compressed using the compression type.

### colorizeByMappingGray:toColor:blackMapping:whiteMapping:

- (void) colorizeByMappingGray: (float)midPoint toColor: (NSColor*)midPointColor blackMapping: (NSColor*)shadowColor whiteMapping: (NSColor*)lightColor;

Description forthcoming.

### getBitmapDataPlanes:

- (void) getBitmapDataPlanes: (unsigned char**)data;

Files the array data with pointers to each of the data planes representing the image. The data array must be allocated to contain at least -samplesPerPixel pointers.

### getCompression:factor:

- (void) getCompression: (NSTIFFCompression*)compression factor: (float*)factor;

Returns the receivers compression and compression factor, which is set either when the image is read in or by -setCompression:factor: . Factor is ignored in many compression schemes. For JPEG compression, factor can be any value from 0 to 255, with 255 being the maximum compression.

### initWithBitmapDataPlanes:pixelsWide:pixelsHigh:bitsPerSample:samplesPerPixel:hasAlpha:isPlanar:colorSpaceName:bytesPerRow:bitsPerPixel:

- (id) initWithBitmapDataPlanes: (unsigned char**)planes pixelsWide: (int)width pixelsHigh: (int)height bitsPerSample: (int)bps samplesPerPixel: (int)spp hasAlpha: (BOOL)alpha isPlanar: (BOOL)isPlanar colorSpaceName: (NSString*)colorSpaceName bytesPerRow: (int)rowBytes bitsPerPixel: (int)pixelBits;
This is a designated initialiser for the class.

Initializes a newly created NSBitmapImageRep object to hold image data specified in the planes buffer and organized according to the additional arguments passed into the method.

The planes argument is an array of char pointers where each array holds a single component or plane of data. Note that if data is passed into the method via planes, the data is NOT copied and not freed when the object is deallocated. It is assumed that the data will always be available. If planes is NULL, then a suitable amount of memory will be allocated to store the information needed. One can then obtain a pointer to the planes data using the -bitmapData or -getBitmapDataPlanes: method.

Each component of the data is in "standard" order, such as red, green, blue for RGB color images. The transparency component, if these is one, should always be last.

The other arguments to the method consist of:

width and height
  The width and height of the image in pixels
bps
  The bits per sample or the number of bits used to store a number in one component of one pixel of the image. Typically this is 8 (bits) but can be 2 or 4, although not all values are supported.
spp
  Samples per pixel, or the number of components of color in the pixel. For instance this would be 4 for an RGB image with transparency.
alpha
  Set to `YES` if the image has a transparency component.
isPlanar
  Set to `YES` if the data is arranged in planes, i.e. one component per buffer as stored in the planes array. If `NO`, then the image data is mixed in one buffer. For instance, for RGB data, the first sample would contain red, then next green, then blue, followed by red for the next pixel.
colorSpaceName
  This argument specifies how the data values are to be interpreted. Possible values include the typical colorspace names (although not all values are currently supported)
rowBytes
  Specifies the number of bytes contained in a single scan line of the data. Normally this can be computed from the width of the image, the samples per pixel and the bits per sample. However, if the data is aligned along word boundaries, this value may differ from this. If rowBytes is 0, the method will calculate the value assuming there are no extra bytes at the end of the scan line.
pixelBits
  This is normally bps for planar data and bps times spp for non-planar data, but sometimes images have extra bits. If pixelBits is 0 it will be calculated as described above.

### initWithBitmapHandle:

- (id) initWithBitmapHandle: (void*)bitmap;

Description forthcoming.

### initWithData:

- (id) initWithData: (NSData*)imageData;

Loads only the default (first) image from the TIFF image contained in data.

### initWithFocusedViewRect:

- (id) initWithFocusedViewRect: (NSRect)rect;

Description forthcoming.

### initWithIconHandle:

- (id) initWithIconHandle: (void*)icon;

Description forthcoming.

### isPlanar

- (BOOL) isPlanar;

Returns `YES` if the image components are stored separately. Returns `NO` if the components are meshed (i.e. all the samples for one pixel come before the next pixel).

### numberOfPlanes

- (int) numberOfPlanes;

Returns the number of planes in an image. Typically this is equal to the number of samples in a planar image or 1 for a non-planar image.

### representationUsingType:properties:

- (NSData*) representationUsingType: (NSBitmapImageFileType)storageType properties: (NSDictionary*)properties;

Description forthcoming.

### samplesPerPixel

- (int) samplesPerPixel;

Returns the number of samples in a pixel. For instance, a normal RGB image with transparency would have a samplesPerPixel of 4.

### setCompression:factor:

- (void) setCompression: (NSTIFFCompression)compression factor: (float)factor;

Description forthcoming.

### setProperty:withValue:

- (void) setProperty: (NSString*)property withValue: (id)value;

Description forthcoming.

### valueForProperty:

- (id) valueForProperty: (NSString*)property;

Description forthcoming.

# Software documentation for the NSBitmapImageRep(GNUstepExtension) category

## NSBitmapImageRep(GNUstepExtension)

> Declared in:
>   AppKit/NSBitmapImageRep.h

> Standards:
> - MacOS-X
> - OpenStep
> - GNUstep

Description forthcoming.

Method summary

- +imageRepsWithFile:

### imageRepsWithFile:

+ (NSArray*) imageRepsWithFile: (NSString*)filename;

Description forthcoming.

Up