1wxImage(3) Erlang Module Definition wxImage(3)
2
6 wxImage - Functions for wxImage class
7
9 This class encapsulates a platform-independent image.
10 An image can be created from data, or using wxBitmap:convertToImage/1.
12 An image can be loaded from a file in a variety of formats, and is ex‐
13 tensible to new formats via image format handlers. Functions are avail‐
14 able to set and get image bits, so it can be used for basic image ma‐
15 nipulation.
16 A wxImage cannot (currently) be drawn directly to a wxDC. Instead, a
18 platform-specific wxBitmap object must be created from it using the
19 wxBitmap::wxBitmap(wxImage,int depth) constructor. This bitmap can then
20 be drawn in a device context, using wxDC:drawBitmap/4.
21 More on the difference between wxImage and wxBitmap: wxImage is just a
23 buffer of RGB bytes with an optional buffer for the alpha bytes. It is
24 all generic, platform independent and image file format independent
25 code. It includes generic code for scaling, resizing, clipping, and
26 other manipulations of the image data. OTOH, wxBitmap is intended to be
27 a wrapper of whatever is the native image format that is quickest/easi‐
28 est to draw to a DC or to be the target of the drawing operations per‐
29 formed on a wxMemoryDC. By splitting the responsibilities between wxIm‐
30 age/wxBitmap like this then it's easier to use generic code shared by
31 all platforms and image types for generic operations and platform spe‐
32 cific code where performance or compatibility is needed.
33 One colour value of the image may be used as a mask colour which will
35 lead to the automatic creation of a wxMask object associated to the
36 bitmap object.
37 Alpha channel support
39 Starting from wxWidgets 2.5.0 wxImage supports alpha channel data, that
41 is in addition to a byte for the red, green and blue colour components
42 for each pixel it also stores a byte representing the pixel opacity.
43 An alpha value of 0 corresponds to a transparent pixel (null opacity)
45 while a value of 255 means that the pixel is 100% opaque. The constants
46 ?wxIMAGE_ALPHA_TRANSPARENT and ?wxIMAGE_ALPHA_OPAQUE can be used to in‐
47 dicate those values in a more readable form.
48 While all images have RGB data, not all images have an alpha channel.
50 Before using getAlpha/3 you should check if this image contains an al‐
51 pha channel with hasAlpha/1. Currently the BMP, PNG, TGA, and TIFF for‐
52 mat handlers have full alpha channel support for loading so if you want
53 to use alpha you have to use one of these formats. If you initialize
54 the image alpha channel yourself using setAlpha/4, you should save it
55 in either PNG, TGA, or TIFF format to avoid losing it as these are the
56 only handlers that currently support saving with alpha.
57 Available image handlers
59 The following image handlers are available. wxBMPHandler is always in‐
61 stalled by default. To use other image formats, install the appropriate
62 handler with wxImage::AddHandler (not implemented in wx) or call ?wx‐
63 InitAllImageHandlers().
64 When saving in PCX format, wxPCXHandler (not implemented in wx) will
66 count the number of different colours in the image; if there are 256 or
67 less colours, it will save as 8 bit, else it will save as 24 bit.
68 Loading PNMs only works for ASCII or raw RGB images. When saving in PNM
70 format, wxPNMHandler (not implemented in wx) will always save as raw
71 RGB.
72 Saving GIFs requires images of maximum 8 bpp (see wxQuantize (not im‐
74 plemented in wx)), and the alpha channel converted to a mask (see con‐
75 vertAlphaToMask/5). Saving an animated GIF requires images of the same
76 size (see wxGIFHandler::SaveAnimation (not implemented in wx))
77 Predefined objects (include wx.hrl): ?wxNullImage
79 See: wxBitmap, ?wxInitAllImageHandlers(), wxPixelData (not implemented
81 in wx)
82 wxWidgets docs: wxImage
84
86 wxImage() = wx:wx_object()
87
89 new() -> wxImage()
90 Creates an empty wxImage object without an alpha channel.
92 new(Name) -> wxImage()
94 new(Sz) -> wxImage()
96 Types:
98 Sz = {W :: integer(), H :: integer()}
100 new(Width, Height) -> wxImage()
102 new(Name, Height :: [Option]) -> wxImage()
104 new(Sz, Data) -> wxImage()
106 new(Sz, Height :: [Option]) -> wxImage()
108 Types:
110 Sz = {W :: integer(), H :: integer()}
112 Option = {clear, boolean()}
113 This is an overloaded member function, provided for convenience.
115 It differs from the above function only in what argument(s) it
116 accepts.
117 new(Width, Height, Data) -> wxImage()
119 new(Width, Height, Data :: [Option]) -> wxImage()
121 new(Name, Mimetype, Data :: [Option]) -> wxImage()
123 new(Sz, Data, Alpha) -> wxImage()
125 Types:
127 Sz = {W :: integer(), H :: integer()}
129 Data = Alpha = binary()
130 This is an overloaded member function, provided for convenience.
132 It differs from the above function only in what argument(s) it
133 accepts.
134 new(Width, Height, Data, Alpha) -> wxImage()
136 Types:
138 Width = Height = integer()
140 Data = Alpha = binary()
141 Creates an image from data in memory.
143 If static_data is false then the wxImage will take ownership of
145 the data and free it afterwards. For this, it has to be allo‐
146 cated with malloc.
147 destroy(This :: wxImage()) -> ok
149 Destructor.
151 See reference-counted object destruction for more info.
153 blur(This, BlurRadius) -> wxImage()
155 Types:
157 This = wxImage()
159 BlurRadius = integer()
160 Blurs the image in both horizontal and vertical directions by
162 the specified pixel blurRadius.
163 This should not be used when using a single mask colour for
165 transparency.
166 See: blurHorizontal/2, blurVertical/2
168 blurHorizontal(This, BlurRadius) -> wxImage()
170 Types:
172 This = wxImage()
174 BlurRadius = integer()
175 Blurs the image in the horizontal direction only.
177 This should not be used when using a single mask colour for
179 transparency.
180 See: blur/2, blurVertical/2
182 blurVertical(This, BlurRadius) -> wxImage()
184 Types:
186 This = wxImage()
188 BlurRadius = integer()
189 Blurs the image in the vertical direction only.
191 This should not be used when using a single mask colour for
193 transparency.
194 See: blur/2, blurHorizontal/2
196 convertAlphaToMask(This) -> boolean()
198 Types:
200 This = wxImage()
202 convertAlphaToMask(This, Options :: [Option]) -> boolean()
204 Types:
206 This = wxImage()
208 Option = {threshold, integer()}
209 If the image has alpha channel, this method converts it to mask.
211 If the image has an alpha channel, all pixels with alpha value
213 less than threshold are replaced with the mask colour and the
214 alpha channel is removed. Otherwise nothing is done.
215 The mask colour is chosen automatically using findFirstUnused‐
217 Colour/2, see the overload below if this is not appropriate.
218 Return: Returns true on success, false on error.
220 convertAlphaToMask(This, Mr, Mg, Mb) -> boolean()
222 Types:
224 This = wxImage()
226 Mr = Mg = Mb = integer()
227 convertAlphaToMask(This, Mr, Mg, Mb, Options :: [Option]) ->
229 boolean()
230 Types:
232 This = wxImage()
234 Mr = Mg = Mb = integer()
235 Option = {threshold, integer()}
236 If the image has alpha channel, this method converts it to mask
238 using the specified colour as the mask colour.
239 If the image has an alpha channel, all pixels with alpha value
241 less than threshold are replaced with the mask colour and the
242 alpha channel is removed. Otherwise nothing is done.
243 Since: 2.9.0
245 Return: Returns true on success, false on error.
247 convertToGreyscale(This) -> wxImage()
249 Types:
251 This = wxImage()
253 Returns a greyscale version of the image.
255 Since: 2.9.0
257 convertToGreyscale(This, Weight_r, Weight_g, Weight_b) ->
259 wxImage()
260 Types:
262 This = wxImage()
264 Weight_r = Weight_g = Weight_b = number()
265 Returns a greyscale version of the image.
267 The returned image uses the luminance component of the original
269 to calculate the greyscale. Defaults to using the standard ITU-T
270 BT.601 when converting to YUV, where every pixel equals (R *
271 weight_r) + (G * weight_g) + (B * weight_b).
272 convertToMono(This, R, G, B) -> wxImage()
274 Types:
276 This = wxImage()
278 R = G = B = integer()
279 Returns monochromatic version of the image.
281 The returned image has white colour where the original has
283 (r,g,b) colour and black colour everywhere else.
284 copy(This) -> wxImage()
286 Types:
288 This = wxImage()
290 Returns an identical copy of this image.
292 create(This, Sz) -> boolean()
294 Types:
296 This = wxImage()
298 Sz = {W :: integer(), H :: integer()}
299 create(This, Width, Height) -> boolean()
301 create(This, Sz, Data) -> boolean()
303 create(This, Sz, Height :: [Option]) -> boolean()
305 Types:
307 This = wxImage()
309 Sz = {W :: integer(), H :: integer()}
310 Option = {clear, boolean()}
311 This is an overloaded member function, provided for convenience.
313 It differs from the above function only in what argument(s) it
314 accepts.
315 create(This, Width, Height, Data) -> boolean()
317 create(This, Width, Height, Data :: [Option]) -> boolean()
319 create(This, Sz, Data, Alpha) -> boolean()
321 Types:
323 This = wxImage()
325 Sz = {W :: integer(), H :: integer()}
326 Data = Alpha = binary()
327 This is an overloaded member function, provided for convenience.
329 It differs from the above function only in what argument(s) it
330 accepts.
331 create(This, Width, Height, Data, Alpha) -> boolean()
333 Types:
335 This = wxImage()
337 Width = Height = integer()
338 Data = Alpha = binary()
339 Creates a fresh image.
341 See new/4 for more info.
343 Return: true if the call succeeded, false otherwise.
345 'Destroy'(This) -> ok
347 Types:
349 This = wxImage()
351 Destroys the image data.
353 findFirstUnusedColour(This) -> Result
355 Types:
357 Result =
359 {Res :: boolean(),
360 R :: integer(),
361 G :: integer(),
362 B :: integer()}
363 This = wxImage()
364 findFirstUnusedColour(This, Options :: [Option]) -> Result
366 Types:
368 Result =
370 {Res :: boolean(),
371 R :: integer(),
372 G :: integer(),
373 B :: integer()}
374 This = wxImage()
375 Option =
376 {startR, integer()} |
377 {startG, integer()} |
378 {startB, integer()}
379 Finds the first colour that is never used in the image.
381 The search begins at given initial colour and continues by in‐
383 creasing R, G and B components (in this order) by 1 until an un‐
384 used colour is found or the colour space exhausted.
385 The parameters r, g, b are pointers to variables to save the
387 colour.
388 The parameters startR, startG, startB define the initial values
390 of the colour. The returned colour will have RGB values equal to
391 or greater than these.
392 Return: Returns false if there is no unused colour left, true on
394 success.
395 Note: This method involves computing the histogram, which is a
397 computationally intensive operation.
398 getImageExtWildcard() -> unicode:charlist()
400 Iterates all registered wxImageHandler (not implemented in wx)
402 objects, and returns a string containing file extension masks
403 suitable for passing to file open/save dialog boxes.
404 Return: The format of the returned string is
406 "(*.ext1;*.ext2)|*.ext1;*.ext2". It is usually a good idea to
407 prepend a description before passing the result to the dialog.
408 Example:
409 See: wxImageHandler (not implemented in wx)
411 getAlpha(This) -> binary()
413 Types:
415 This = wxImage()
417 Returns pointer to the array storing the alpha values for this
419 image.
420 This pointer is NULL for the images without the alpha channel.
422 If the image does have it, this pointer may be used to directly
423 manipulate the alpha values which are stored as the RGB ones.
424 getAlpha(This, X, Y) -> integer()
426 Types:
428 This = wxImage()
430 X = Y = integer()
431 Return alpha value at given pixel location.
433 getBlue(This, X, Y) -> integer()
435 Types:
437 This = wxImage()
439 X = Y = integer()
440 Returns the blue intensity at the given coordinate.
442 getData(This) -> binary()
444 Types:
446 This = wxImage()
448 Returns the image data as an array.
450 This is most often used when doing direct image manipulation.
452 The return value points to an array of characters in RGBRG‐
453 BRGB... format in the top-to-bottom, left-to-right order, that
454 is the first RGB triplet corresponds to the first pixel of the
455 first row, the second one - to the second pixel of the first row
456 and so on until the end of the first row, with second row fol‐
457 lowing after it and so on.
458 You should not delete the returned pointer nor pass it to set‐
460 Data/4.
461 getGreen(This, X, Y) -> integer()
463 Types:
465 This = wxImage()
467 X = Y = integer()
468 Returns the green intensity at the given coordinate.
470 getImageCount(Filename) -> integer()
472 Types:
474 Filename = unicode:chardata()
476 getImageCount(Filename, Options :: [Option]) -> integer()
478 Types:
480 Filename = unicode:chardata()
482 Option = {type, wx:wx_enum()}
483 If the image file contains more than one image and the image
485 handler is capable of retrieving these individually, this func‐
486 tion will return the number of available images.
487 For the overload taking the parameter filename, that's the name
489 of the file to query. For the overload taking the parameter
490 stream, that's the opened input stream with image data.
491 See wxImageHandler::GetImageCount() (not implemented in wx) for
493 more info.
494 The parameter type may be one of the following values:
496 Return: Number of available images. For most image handlers,
498 this is 1 (exceptions are TIFF and ICO formats as well as ani‐
499 mated GIFs for which this function returns the number of frames
500 in the animation).
501 getHeight(This) -> integer()
503 Types:
505 This = wxImage()
507 Gets the height of the image in pixels.
509 See: getWidth/1, GetSize() (not implemented in wx)
511 getMaskBlue(This) -> integer()
513 Types:
515 This = wxImage()
517 Gets the blue value of the mask colour.
519 getMaskGreen(This) -> integer()
521 Types:
523 This = wxImage()
525 Gets the green value of the mask colour.
527 getMaskRed(This) -> integer()
529 Types:
531 This = wxImage()
533 Gets the red value of the mask colour.
535 getOrFindMaskColour(This) -> Result
537 Types:
539 Result =
541 {Res :: boolean(),
542 R :: integer(),
543 G :: integer(),
544 B :: integer()}
545 This = wxImage()
546 Get the current mask colour or find a suitable unused colour
548 that could be used as a mask colour.
549 Returns true if the image currently has a mask.
551 getPalette(This) -> wxPalette:wxPalette()
553 Types:
555 This = wxImage()
557 Returns the palette associated with the image.
559 Currently the palette is only used when converting to wxBitmap
561 under Windows.
562 Some of the wxImage handlers have been modified to set the pal‐
564 ette if one exists in the image file (usually 256 or less colour
565 images in GIF or PNG format).
566 getRed(This, X, Y) -> integer()
568 Types:
570 This = wxImage()
572 X = Y = integer()
573 Returns the red intensity at the given coordinate.
575 getSubImage(This, Rect) -> wxImage()
577 Types:
579 This = wxImage()
581 Rect =
582 {X :: integer(),
583 Y :: integer(),
584 W :: integer(),
585 H :: integer()}
586 Returns a sub image of the current one as long as the rect be‐
588 longs entirely to the image.
589 getWidth(This) -> integer()
591 Types:
593 This = wxImage()
595 Gets the width of the image in pixels.
597 See: getHeight/1, GetSize() (not implemented in wx)
599 hasAlpha(This) -> boolean()
601 Types:
603 This = wxImage()
605 Returns true if this image has alpha channel, false otherwise.
607 See: getAlpha/3, setAlpha/4
609 hasMask(This) -> boolean()
611 Types:
613 This = wxImage()
615 Returns true if there is a mask active, false otherwise.
617 getOption(This, Name) -> unicode:charlist()
619 Types:
621 This = wxImage()
623 Name = unicode:chardata()
624 Gets a user-defined string-valued option.
626 Generic options:
628 Options specific to wxGIFHandler (not implemented in wx):
630 Return: The value of the option or an empty string if not found.
632 Use hasOption/2 if an empty string can be a valid option value.
633 See: setOption/3, getOptionInt/2, hasOption/2
635 getOptionInt(This, Name) -> integer()
637 Types:
639 This = wxImage()
641 Name = unicode:chardata()
642 Gets a user-defined integer-valued option.
644 The function is case-insensitive to name. If the given option is
646 not present, the function returns 0. Use hasOption/2 if 0 is a
647 possibly valid value for the option.
648 Generic options:
650 Since: 2.9.3
652 Options specific to wxPNGHandler (not implemented in wx):
654 Options specific to wxTIFFHandler (not implemented in wx):
656 Options specific to wxGIFHandler (not implemented in wx):
658 Note: Be careful when combining the options wxIMAGE_OP‐
660 TION_TIFF_SAMPLESPERPIXEL, wxIMAGE_OPTION_TIFF_BITSPERSAMPLE,
661 and wxIMAGE_OPTION_TIFF_PHOTOMETRIC. While some measures are
662 taken to prevent illegal combinations and/or values, it is still
663 easy to abuse them and come up with invalid results in the form
664 of either corrupted images or crashes.
665 Return: The value of the option or 0 if not found. Use hasOp‐
667 tion/2 if 0 can be a valid option value.
668 See: setOption/3, getOption/2
670 hasOption(This, Name) -> boolean()
672 Types:
674 This = wxImage()
676 Name = unicode:chardata()
677 Returns true if the given option is present.
679 The function is case-insensitive to name.
681 The lists of the currently supported options are in getOption/2
683 and getOptionInt/2 function docs.
684 See: setOption/3, getOption/2, getOptionInt/2
686 initAlpha(This) -> ok
688 Types:
690 This = wxImage()
692 Initializes the image alpha channel data.
694 It is an error to call it if the image already has alpha data.
696 If it doesn't, alpha data will be by default initialized to all
697 pixels being fully opaque. But if the image has a mask colour,
698 all mask pixels will be completely transparent.
699 initStandardHandlers() -> ok
701 Internal use only.
703 Adds standard image format handlers. It only install wxBMPHan‐
705 dler for the time being, which is used by wxBitmap.
706 This function is called by wxWidgets on startup, and shouldn't
708 be called by the user.
709 See: wxImageHandler (not implemented in wx), ?wxInitAllImageHan‐
711 dlers(), wxQuantize (not implemented in wx)
712 isTransparent(This, X, Y) -> boolean()
714 Types:
716 This = wxImage()
718 X = Y = integer()
719 isTransparent(This, X, Y, Options :: [Option]) -> boolean()
721 Types:
723 This = wxImage()
725 X = Y = integer()
726 Option = {threshold, integer()}
727 Returns true if the given pixel is transparent, i.e. either has
729 the mask colour if this image has a mask or if this image has
730 alpha channel and alpha value of this pixel is strictly less
731 than threshold.
732 loadFile(This, Name) -> boolean()
734 Types:
736 This = wxImage()
738 Name = unicode:chardata()
739 loadFile(This, Name, Options :: [Option]) -> boolean()
741 Types:
743 This = wxImage()
745 Name = unicode:chardata()
746 Option = {type, wx:wx_enum()} | {index, integer()}
747 Loads an image from a file.
749 If no handler type is provided, the library will try to autode‐
751 tect the format.
752 loadFile(This, Name, Mimetype, Options :: [Option]) -> boolean()
754 Types:
756 This = wxImage()
758 Name = Mimetype = unicode:chardata()
759 Option = {index, integer()}
760 Loads an image from a file.
762 If no handler type is provided, the library will try to autode‐
764 tect the format.
765 ok(This) -> boolean()
767 Types:
769 This = wxImage()
771 See: isOk/1.
773 isOk(This) -> boolean()
775 Types:
777 This = wxImage()
779 Returns true if image data is present.
781 removeHandler(Name) -> boolean()
783 Types:
785 Name = unicode:chardata()
787 Finds the handler with the given name, and removes it.
789 The handler is also deleted.
791 Return: true if the handler was found and removed, false other‐
793 wise.
794 See: wxImageHandler (not implemented in wx)
796 mirror(This) -> wxImage()
798 Types:
800 This = wxImage()
802 mirror(This, Options :: [Option]) -> wxImage()
804 Types:
806 This = wxImage()
808 Option = {horizontally, boolean()}
809 Returns a mirrored copy of the image.
811 The parameter horizontally indicates the orientation.
813 replace(This, R1, G1, B1, R2, G2, B2) -> ok
815 Types:
817 This = wxImage()
819 R1 = G1 = B1 = R2 = G2 = B2 = integer()
820 Replaces the colour specified by r1,g1,b1 by the colour
822 r2,g2,b2.
823 rescale(This, Width, Height) -> wxImage()
825 Types:
827 This = wxImage()
829 Width = Height = integer()
830 rescale(This, Width, Height, Options :: [Option]) -> wxImage()
832 Types:
834 This = wxImage()
836 Width = Height = integer()
837 Option = {quality, wx:wx_enum()}
838 Changes the size of the image in-place by scaling it: after a
840 call to this function,the image will have the given width and
841 height.
842 For a description of the quality parameter, see the scale/4
844 function. Returns the (modified) image itself.
845 See: scale/4
847 resize(This, Size, Pos) -> wxImage()
849 Types:
851 This = wxImage()
853 Size = {W :: integer(), H :: integer()}
854 Pos = {X :: integer(), Y :: integer()}
855 resize(This, Size, Pos, Options :: [Option]) -> wxImage()
857 Types:
859 This = wxImage()
861 Size = {W :: integer(), H :: integer()}
862 Pos = {X :: integer(), Y :: integer()}
863 Option = {r, integer()} | {g, integer()} | {b, integer()}
864 Changes the size of the image in-place without scaling it by
866 adding either a border with the given colour or cropping as nec‐
867 essary.
868 The image is pasted into a new image with the given size and
870 background colour at the position pos relative to the upper left
871 of the new image.
872 If red = green = blue = -1 then use either the current mask
874 colour if set or find, use, and set a suitable mask colour for
875 any newly exposed areas.
876 Return: The (modified) image itself.
878 See: size/4
880 rotate(This, Angle, RotationCentre) -> wxImage()
882 Types:
884 This = wxImage()
886 Angle = number()
887 RotationCentre = {X :: integer(), Y :: integer()}
888 rotate(This, Angle, RotationCentre, Options :: [Option]) ->
890 wxImage()
891 Types:
893 This = wxImage()
895 Angle = number()
896 RotationCentre = {X :: integer(), Y :: integer()}
897 Option =
898 {interpolating, boolean()} |
899 {offset_after_rotation, {X :: integer(), Y :: integer()}}
900 Rotates the image about the given point, by angle radians.
902 Passing true to interpolating results in better image quality,
904 but is slower.
905 If the image has a mask, then the mask colour is used for the
907 uncovered pixels in the rotated image background. Else, black
908 (rgb 0, 0, 0) will be used.
909 Returns the rotated image, leaving this image intact.
911 rotateHue(This, Angle) -> ok
913 Types:
915 This = wxImage()
917 Angle = number()
918 Rotates the hue of each pixel in the image by angle, which is a
920 double in the range of -1.0 to +1.0, where -1.0 corresponds to
921 -360 degrees and +1.0 corresponds to +360 degrees.
922 rotate90(This) -> wxImage()
924 Types:
926 This = wxImage()
928 rotate90(This, Options :: [Option]) -> wxImage()
930 Types:
932 This = wxImage()
934 Option = {clockwise, boolean()}
935 Returns a copy of the image rotated 90 degrees in the direction
937 indicated by clockwise.
938 saveFile(This, Name) -> boolean()
940 Types:
942 This = wxImage()
944 Name = unicode:chardata()
945 Saves an image in the named file.
947 File type is determined from the extension of the file name.
949 Note that this function may fail if the extension is not recog‐
950 nized! You can use one of the forms above to save images to
951 files with non-standard extensions.
952 saveFile(This, Name, Type) -> boolean()
954 saveFile(This, Name, Mimetype) -> boolean()
956 Types:
958 This = wxImage()
960 Name = Mimetype = unicode:chardata()
961 Saves an image in the named file.
963 scale(This, Width, Height) -> wxImage()
965 Types:
967 This = wxImage()
969 Width = Height = integer()
970 scale(This, Width, Height, Options :: [Option]) -> wxImage()
972 Types:
974 This = wxImage()
976 Width = Height = integer()
977 Option = {quality, wx:wx_enum()}
978 Returns a scaled version of the image.
980 This is also useful for scaling bitmaps in general as the only
982 other way to scale bitmaps is to blit a wxMemoryDC into another
983 wxMemoryDC.
984 The parameter quality determines what method to use for resam‐
986 pling the image, see wxImageResizeQuality documentation.
987 It should be noted that although using wxIMAGE_QUALITY_HIGH pro‐
989 duces much nicer looking results it is a slower method. Downsam‐
990 pling will use the box averaging method which seems to operate
991 very fast. If you are upsampling larger images using this method
992 you will most likely notice that it is a bit slower and in ex‐
993 treme cases it will be quite substantially slower as the bicubic
994 algorithm has to process a lot of data.
995 It should also be noted that the high quality scaling may not
997 work as expected when using a single mask colour for transpar‐
998 ency, as the scaling will blur the image and will therefore re‐
999 move the mask partially. Using the alpha channel will work.
1000 Example:
1002 See: rescale/4
1004 size(This, Size, Pos) -> wxImage()
1006 Types:
1008 This = wxImage()
1010 Size = {W :: integer(), H :: integer()}
1011 Pos = {X :: integer(), Y :: integer()}
1012 size(This, Size, Pos, Options :: [Option]) -> wxImage()
1014 Types:
1016 This = wxImage()
1018 Size = {W :: integer(), H :: integer()}
1019 Pos = {X :: integer(), Y :: integer()}
1020 Option = {r, integer()} | {g, integer()} | {b, integer()}
1021 Returns a resized version of this image without scaling it by
1023 adding either a border with the given colour or cropping as nec‐
1024 essary.
1025 The image is pasted into a new image with the given size and
1027 background colour at the position pos relative to the upper left
1028 of the new image.
1029 If red = green = blue = -1 then the areas of the larger image
1031 not covered by this image are made transparent by filling them
1032 with the image mask colour (which will be allocated automati‐
1033 cally if it isn't currently set).
1034 Otherwise, the areas will be filled with the colour with the
1036 specified RGB components.
1037 See: resize/4
1039 setAlpha(This, Alpha) -> ok
1041 Types:
1043 This = wxImage()
1045 Alpha = binary()
1046 This function is similar to setData/4 and has similar restric‐
1048 tions.
1049 The pointer passed to it may however be NULL in which case the
1051 function will allocate the alpha array internally - this is use‐
1052 ful to add alpha channel data to an image which doesn't have
1053 any.
1054 If the pointer is not NULL, it must have one byte for each image
1056 pixel and be allocated with malloc(). wxImage takes ownership of
1057 the pointer and will free it unless static_data parameter is set
1058 to true - in this case the caller should do it.
1059 setAlpha(This, X, Y, Alpha) -> ok
1061 Types:
1063 This = wxImage()
1065 X = Y = Alpha = integer()
1066 Sets the alpha value for the given pixel.
1068 This function should only be called if the image has alpha chan‐
1070 nel data, use hasAlpha/1 to check for this.
1071 setData(This, Data) -> ok
1073 Types:
1075 This = wxImage()
1077 Data = binary()
1078 Sets the image data without performing checks.
1080 The data given must have the size (width*height*3) or results
1082 will be unexpected. Don't use this method if you aren't sure you
1083 know what you are doing.
1084 The data must have been allocated with malloc(), NOT with opera‐
1086 tor new.
1087 If static_data is false, after this call the pointer to the data
1089 is owned by the wxImage object, that will be responsible for
1090 deleting it. Do not pass to this function a pointer obtained
1091 through getData/1.
1092 setData(This, Data, New_width, New_height) -> ok
1094 Types:
1096 This = wxImage()
1098 Data = binary()
1099 New_width = New_height = integer()
1100 This is an overloaded member function, provided for convenience.
1102 It differs from the above function only in what argument(s) it
1103 accepts.
1104 setMask(This) -> ok
1106 Types:
1108 This = wxImage()
1110 setMask(This, Options :: [Option]) -> ok
1112 Types:
1114 This = wxImage()
1116 Option = {mask, boolean()}
1117 Specifies whether there is a mask or not.
1119 The area of the mask is determined by the current mask colour.
1121 setMaskColour(This, Red, Green, Blue) -> ok
1123 Types:
1125 This = wxImage()
1127 Red = Green = Blue = integer()
1128 Sets the mask colour for this image (and tells the image to use
1130 the mask).
1131 setMaskFromImage(This, Mask, Mr, Mg, Mb) -> boolean()
1133 Types:
1135 This = Mask = wxImage()
1137 Mr = Mg = Mb = integer()
1138 Sets image's mask so that the pixels that have RGB value of
1140 mr,mg,mb in mask will be masked in the image.
1141 This is done by first finding an unused colour in the image,
1143 setting this colour as the mask colour and then using this
1144 colour to draw all pixels in the image who corresponding pixel
1145 in mask has given RGB value.
1146 The parameter mask is the mask image to extract mask shape from.
1148 It must have the same dimensions as the image.
1149 The parameters mr, mg, mb are the RGB values of the pixels in
1151 mask that will be used to create the mask.
1152 Return: Returns false if mask does not have same dimensions as
1154 the image or if there is no unused colour left. Returns true if
1155 the mask was successfully applied.
1156 Note: Note that this method involves computing the histogram,
1158 which is a computationally intensive operation.
1159 setOption(This, Name, Value) -> ok
1161 setOption(This, Name, Value) -> ok
1163 Types:
1165 This = wxImage()
1167 Name = Value = unicode:chardata()
1168 Sets a user-defined option.
1170 The function is case-insensitive to name.
1172 For example, when saving as a JPEG file, the option quality is
1174 used, which is a number between 0 and 100 (0 is terrible, 100 is
1175 very good).
1176 The lists of the currently supported options are in getOption/2
1178 and getOptionInt/2 function docs.
1179 See: getOption/2, getOptionInt/2, hasOption/2
1181 setPalette(This, Palette) -> ok
1183 Types:
1185 This = wxImage()
1187 Palette = wxPalette:wxPalette()
1188 Associates a palette with the image.
1190 The palette may be used when converting wxImage to wxBitmap (MSW
1192 only at present) or in file save operations (none as yet).
1193 setRGB(This, Rect, Red, Green, Blue) -> ok
1195 Types:
1197 This = wxImage()
1199 Rect =
1200 {X :: integer(),
1201 Y :: integer(),
1202 W :: integer(),
1203 H :: integer()}
1204 Red = Green = Blue = integer()
1205 Sets the colour of the pixels within the given rectangle.
1207 This routine performs bounds-checks for the coordinate so it can
1209 be considered a safe way to manipulate the data.
1210 setRGB(This, X, Y, R, G, B) -> ok
1212 Types:
1214 This = wxImage()
1216 X = Y = R = G = B = integer()
1217 Set the color of the pixel at the given x and y coordinate.
1219wxWidgets team. wx 2.3.1 wxImage(3)