pixel_iterator
Pixel iterator pattern support functions
Contents
InitializePixelIteratorOptions
Synopsis
void InitializePixelIteratorOptions( PixelIteratorOptions *options,
                                     ExceptionInfo *exception );
Description
InitializePixelIteratorOptions() assigns default options to a user-provided PixelIteratorOptions structure. This function should always be used to initialize the PixelIteratorOptions structure prior to making any changes to it.
The format of the InitializePixelIteratorOptions method is:
void InitializePixelIteratorOptions( PixelIteratorOptions *options,
                                     ExceptionInfo *exception );
- options:
- pointer to PixelIteratorOptions structure to initialize. 
- exception:
- Return any errors or warnings in this structure. 
PixelIterateMonoRead
Synopsis
MagickPassFail PixelIterateMonoRead( PixelIteratorMonoReadCallback call_back,
                                     const PixelIteratorOptions *options,
                                     const char *description, void *mutable_data,
                                     const void *immutable_data, const long x, const long y,
                                     const unsigned long columns, const unsigned long rows,
                                     const Image *image, ExceptionInfo *exception );
Description
PixelIterateMonoRead() iterates through a region of an image and invokes a user-provided callback function (of type PixelRowIteratorMonoReadCallback) for a row of pixels. This is useful to support simple operations such as statistics computation.
The format of the PixelIterateMonoRead method is:
MagickPassFail PixelIterateMonoRead( PixelIteratorMonoReadCallback call_back,
                                     const PixelIteratorOptions *options,
                                     const char *description, void *mutable_data,
                                     const void *immutable_data, const long x, const long y,
                                     const unsigned long columns, const unsigned long rows,
                                     const Image *image, ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which is passed the address of pixels from the image. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- x:
- The horizontal ordinate of the top left corner of the region. 
- y:
- The vertical ordinate of the top left corner of the region. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- image:
- The address of the Image. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateMonoSet
Synopsis
MagickPassFail PixelIterateMonoSet( PixelIteratorMonoModifyback call_back,
                                    const PixelIteratorOptions *options,
                                    const char *description, void *mutable_data,
                                    const void *immutable_data, const long x, const long y,
                                    const unsigned long columns, const unsigned long rows,
                                    Image *image, ExceptionInfo *exception );
Description
PixelIterateMonoSet() iterates through a region of an image and invokes a user-provided callback function (of type PixelIteratorMonoModifyCallback) to initialize a region of pixels from scratch. The difference from PixelIterateMonoModify() is that the output pixels are not initialized from the underlying store so it is more efficient when outputting a new image or when the existing pixels are intentionally discarded. This is useful for operations such as setting the pixel color.
The format of the PixelIterateMonoSet method is:
MagickPassFail PixelIterateMonoSet( PixelIteratorMonoModifyback call_back,
                                    const PixelIteratorOptions *options,
                                    const char *description, void *mutable_data,
                                    const void *immutable_data, const long x, const long y,
                                    const unsigned long columns, const unsigned long rows,
                                    Image *image, ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which is passed the address of pixels to be initialized in the image. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- x:
- The horizontal ordinate of the top left corner of the region. 
- y:
- The vertical ordinate of the top left corner of the region. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- image:
- The address of the Image. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateMonoModify
Synopsis
MagickPassFail PixelIterateMonoModify( PixelIteratorMonoModifyCallback call_back,
                                       const PixelIteratorOptions *options,
                                       const char *description, void *mutable_data,
                                       const void *immutable_data, const long x,
                                       const long y, const unsigned long columns,
                                       const unsigned long rows, Image *image,
                                       ExceptionInfo *exception );
Description
PixelIterateMonoModify() iterates through a region of an image and invokes a user-provided callback function (of type PixelIteratorMonoModifyCallback) to modify a region of pixels. This is useful to support simple operations such as level shifting, colorspace translation, or thresholding.
The format of the PixelIterateMonoModify method is:
MagickPassFail PixelIterateMonoModify( PixelIteratorMonoModifyCallback call_back,
                                       const PixelIteratorOptions *options,
                                       const char *description, void *mutable_data,
                                       const void *immutable_data, const long x,
                                       const long y, const unsigned long columns,
                                       const unsigned long rows, Image *image,
                                       ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which is passed the address of pixels from the image. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- x:
- The horizontal ordinate of the top left corner of the region. 
- y:
- The vertical ordinate of the top left corner of the region. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- image:
- The address of the Image. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateDualRead
Synopsis
MagickPassFail PixelIterateDualRead( PixelIteratorDualReadCallback call_back,
                                     const PixelIteratorOptions *options,
                                     const char *description, void *mutable_data,
                                     const void *immutable_data, const unsigned long columns,
                                     const unsigned long rows, const Image *first_image,
                                     const long first_x, const long first_y,
                                     const Image *second_image, const long second_x,
                                     const long second_y, ExceptionInfo *exception ); ;
Description
PixelIterateDualRead() iterates through pixel regions of two images and invokes a user-provided callback function (of type PixelIteratorDualReadCallback) for each row of pixels. This is useful to support operations such as image comparison.
The format of the PixelIterateDualRead method is:
MagickPassFail PixelIterateDualRead( PixelIteratorDualReadCallback call_back,
                                     const PixelIteratorOptions *options,
                                     const char *description, void *mutable_data,
                                     const void *immutable_data, const unsigned long columns,
                                     const unsigned long rows, const Image *first_image,
                                     const long first_x, const long first_y,
                                     const Image *second_image, const long second_x,
                                     const long second_y, ExceptionInfo *exception ); ;
- call_back:
- A user-provided C callback function which is passed the address of pixels from each image. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- first_image:
- The address of the first Image. 
- first_x:
- The horizontal ordinate of the top left corner of the first region. 
- first_y:
- The vertical ordinate of the top left corner of the first region. 
- second_image:
- The address of the second Image. 
- second_x:
- The horizontal ordinate of the top left corner of the second region. 
- second_y:
- The vertical ordinate of the top left corner of the second region. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateDualModify
Synopsis
MagickPassFail PixelIterateDualModify( PixelIteratorDualModifyCallback call_back,
                                       const PixelIteratorOptions *options,
                                       const char *description, void *mutable_data,
                                       const void *immutable_data,
                                       const unsigned long columns, const unsigned long rows,
                                       const Image *source_image, const long source_x,
                                       const long source_y, Image *update_image,
                                       const long update_x, const long update_y,
                                       ExceptionInfo *exception );
Description
PixelIterateDualModify() iterates through pixel regions of two images and invokes a user-provided callback function (of type PixelIteratorDualModifyCallback) for each row of pixels. This is useful to support operations such as composition.
The format of the PixelIterateDualModify method is:
MagickPassFail PixelIterateDualModify( PixelIteratorDualModifyCallback call_back,
                                       const PixelIteratorOptions *options,
                                       const char *description, void *mutable_data,
                                       const void *immutable_data,
                                       const unsigned long columns, const unsigned long rows,
                                       const Image *source_image, const long source_x,
                                       const long source_y, Image *update_image,
                                       const long update_x, const long update_y,
                                       ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which reads from a region of source pixels and updates a region of destination pixels. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- source_image:
- The address of the constant source Image. 
- source_x:
- The horizontal ordinate of the top left corner of the source region. 
- source_y:
- The vertical ordinate of the top left corner of the source region. 
- update_image:
- The address of the update Image. 
- update_x:
- The horizontal ordinate of the top left corner of the update region. 
- update_y:
- The vertical ordinate of the top left corner of the update region. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateDualNew
Synopsis
MagickPassFail PixelIterateDualNew( PixelIteratorDualNewCallback call_back,
                                    const PixelIteratorOptions *options,
                                    const char *description, void *mutable_data,
                                    const void *immutable_data, const unsigned long columns,
                                    const unsigned long rows, const Image *source_image,
                                    const long source_x, const long source_y,
                                    Image *new_image, const long new_x,
                                    const long new_y, ExceptionInfo *exception );
Description
PixelIterateDualNew() iterates through pixel regions of two images and invokes a user-provided callback function (of type PixelIteratorDualNewCallback) for each row of pixels. This is used if a new output image is created based on an input image. The difference from PixelIterateDualModify() is that the output pixels are not initialized so it is more efficient when outputting a new image.
The format of the PixelIterateDualNew method is:
MagickPassFail PixelIterateDualNew( PixelIteratorDualNewCallback call_back,
                                    const PixelIteratorOptions *options,
                                    const char *description, void *mutable_data,
                                    const void *immutable_data, const unsigned long columns,
                                    const unsigned long rows, const Image *source_image,
                                    const long source_x, const long source_y,
                                    Image *new_image, const long new_x,
                                    const long new_y, ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which reads from a region of source pixels and initializes a region of destination pixels. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- source_image:
- The address of the constant source Image. 
- source_x:
- The horizontal ordinate of the top left corner of the source region. 
- source_y:
- The vertical ordinate of the top left corner of the source region. 
- new_image:
- The address of the new Image. 
- new_x:
- The horizontal ordinate of the top left corner of the new region. 
- new_y:
- The vertical ordinate of the top left corner of the new region. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateTripleModify
Synopsis
MagickPassFail PixelIterateTripleModify( PixelIteratorTripleModifyCallback call_back,
                                         const PixelIteratorOptions *options,
                                         const char *description, void *mutable_data,
                                         const void *immutable_data,
                                         const unsigned long columns, const unsigned long rows,
                                         const Image *source1_image,
                                         const Image *source2_image, const long source_x,
                                         const long source_y, Image *update_image,
                                         const long update_x, const long update_y,
                                         ExceptionInfo *exception );
Description
PixelIterateTripleModify() iterates through pixel regions of three images and invokes a user-provided callback function (of type PixelIteratorTripleModifyCallback) for each row of pixels. The first two images are read-only, while the third image is read-write for update. Access of the first two images is done lock-step using the same coordinates. This is useful to support operations such as image differencing.
The format of the PixelIterateTripleModify method is:
MagickPassFail PixelIterateTripleModify( PixelIteratorTripleModifyCallback call_back,
                                         const PixelIteratorOptions *options,
                                         const char *description, void *mutable_data,
                                         const void *immutable_data,
                                         const unsigned long columns, const unsigned long rows,
                                         const Image *source1_image,
                                         const Image *source2_image, const long source_x,
                                         const long source_y, Image *update_image,
                                         const long update_x, const long update_y,
                                         ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which reads from a region of source pixels and updates a region of destination pixels. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- source1_image:
- The address of the constant source 1 Image. 
- source2_image:
- The address of the constant source 2 Image. 
- source_x:
- The horizontal ordinate of the top left corner of the source regions. 
- source_y:
- The vertical ordinate of the top left corner of the source regions. 
- update_image:
- The address of the update Image. 
- update_x:
- The horizontal ordinate of the top left corner of the update region. 
- update_y:
- The vertical ordinate of the top left corner of the update region. 
- exception:
- If an error is reported, this argument is updated with the reason. 
PixelIterateTripleNew
Synopsis
MagickPassFail PixelIterateTripleNew( PixelIteratorTripleNewCallback call_back,
                                      const PixelIteratorOptions *options,
                                      const char *description, void *mutable_data,
                                      const void *immutable_data,
                                      const unsigned long columns, const unsigned long rows,
                                      const Image *source1_image,
                                      const Image *source2_image, const long source_x,
                                      const long source_y, Image *new_image,
                                      const long new_x, const long new_y,
                                      ExceptionInfo *exception );
Description
PixelIterateTripleNew() iterates through pixel regions of three images and invokes a user-provided callback function (of type PixelIteratorTripleNewCallback) for each row of pixels. The first two images are read-only, while the third image is read-write for update. Access of the first two images is done lock-step using the same coordinates. This is used if a new output image is created based on two input images. The difference from PixelIterateTripleModify() is that the output pixels are not initialized so it is more efficient when outputting a new image.
The format of the PixelIterateTripleNew method is:
MagickPassFail PixelIterateTripleNew( PixelIteratorTripleNewCallback call_back,
                                      const PixelIteratorOptions *options,
                                      const char *description, void *mutable_data,
                                      const void *immutable_data,
                                      const unsigned long columns, const unsigned long rows,
                                      const Image *source1_image,
                                      const Image *source2_image, const long source_x,
                                      const long source_y, Image *new_image,
                                      const long new_x, const long new_y,
                                      ExceptionInfo *exception );
- call_back:
- A user-provided C callback function which reads from a region of source pixels and initializes a region of destination pixels. 
- options:
- Pixel iterator execution options (may be NULL). 
- description:
- textual description of operation being performed. 
- mutable_data:
- User-provided mutable context data. 
- immutable_data:
- User-provided immutable context data. 
- columns:
- Width of pixel region 
- rows:
- Height of pixel region 
- source1_image:
- The address of the constant source 1 Image. 
- source2_image:
- The address of the constant source 2 Image. 
- source_x:
- The horizontal ordinate of the top left corner of the source regions. 
- source_y:
- The vertical ordinate of the top left corner of the source regions. 
- new_image:
- The address of the new Image. 
- new_x:
- The horizontal ordinate of the top left corner of the new region. 
- new_y:
- The vertical ordinate of the top left corner of the new region. 
- exception:
- If an error is reported, this argument is updated with the reason. 
