1pod::Prima::image-load(U3s)er Contributed Perl Documentatpioodn::Prima::image-load(3)
2
6 Prima::image-load - Using image subsystem
7
9 Details on image subsystem - image loading, saving, and codec
10 managements
11
13 Simple loading
14 Simplest case, loading a single image would look like:
15 my $x = Prima::Image-> load( 'filename.duf');
17 die "$@" unless $x;
18 Image functions can work being either invoked from package, or from
20 existing Prima::Image object, in latter case the caller object itself
21 is changing. The code above could be also written as
22 my $x = Prima::Image-> create;
24 die "$@" unless $x-> load( 'filename.duf');
25 In both cases $x contains image data upon success. Error is returned
27 into $@ variable ( see perldoc perlvar for more info).
28 Loading from stream
30 "Prima::Image" can also load image by reading from a stream:
31 open FILE, 'a.jpeg' or die "Cannot open:$!";
33 binmode FILE;
34 my $x = Prima::Image-> load( \*FILE);
35 die "$@" unless $x;
36 Multiframe loading
38 Multiframe load call can be also issued in two ways:
39 my @x = Prima::Image-> load( 'filename.duf', loadAll => 1);
41 die "$@" unless $x[-1];
42 my $x = Prima::Image-> create;
44 my @x = $x-> load( 'filename.duf', loadAll => 1);
45 die "$@" unless $x[-1];
46 In second case, the content of the first frame comes to $x and $x[0].
48 Sufficient check for error is whether last item of a returned array is
49 defined. This check works also if an empty array is returned. Only
50 this last item can be an undefined value, others are guaranteed to be
51 valid objects.
52 Multiframe syntax is expressed in a set of extra hash keys. These keys
54 are:
55 loadAll
57 Request for loading all frames that can be read from a file.
58 Example:
59 loadAll => 1
61 index
63 If present, returns a single frame with index given. Example:
64 index => 8
66 map Contains an anonymous array of frame indices to load. Valid
68 indices are above zero, negative ones can't be counted in a way
69 perl array indices are. Example:
70 map => [0, 10, 15..20]
72 Querying extra information
74 By default Prima loads image data and palette only. For any other
75 information that can be loaded, anonymous hash 'extras' can be defined.
76 To notify a codec that this extra information is desired, loadExtras
77 boolean value is used. Example:
78 my $x = Prima::Image-> load( $f, loadExtras => 1);
80 die "$@" unless $x;
81 for ( keys %{$x-> {extras}}) {
82 print " $_ : $x->{extras}->{$_}\n";
83 }
84 The code above loads and prints extra information read from a file.
86 Typical output, for example, from a gif codec based on libgif would
87 look like:
88 codecID : 1
90 transparentColorIndex : 1
91 comment : created by GIMP
92 frames : 18
93 'codecID' is a Prima-defined extra field, which is an index of the
95 codec which have loaded the file. This field's value is useful for
96 explicit indication of codec on the save request.
97 'frames' is also a Prima-defined extra field, with integer value set to
99 a number of frames in the image. It might be set to -1, signaling that
100 codec is incapable of quick reading of the frame count. If, however,
101 it is necessary to get actual frame count, a 'wantFrames' profile
102 boolean value should be set to 1 - then frames is guaranteed to be set
103 to a 0 or positive value, but the request may take longer time,
104 especially on a large file with sequential access. Real life example is
105 a gif file with more than thousand frames. 'wantFrames' is useful in
106 null load requests.
107 Multiprofile loading requests
109 The parameters that are accepted by load, are divided into several
110 categories - first, those that apply to all loading process and those
111 who apply only to a particular frame. Those who are defined by Prima,
112 are enumerated above - loadExtras, loadAll etc. Only loadExtras,
113 noImageData, noIncomplete and iconUnmask are applicable to a frame,
114 other govern the loading process. A codec may as well define its own
115 parameters, however it is not possible to tell what parameter belongs
116 to what group - this information is to be found in codec documentation;
117 The parameters that applicable to any frame, can be specified
119 separately to every desirable frame in single call. For that purpose,
120 parameter 'profiles' is defined. 'profiles' is expected to be an
121 anonymous array of hashes, each hash where corresponds to a request
122 number. Example:
123 $x-> load( $f, loadAll => 1, profiles => [
125 {loadExtras => 0},
126 {loadExtras => 1},
127 ]);
128 First hash there applies to frame index 0, second - to frame index 1.
130 Note that in code
131 $x-> load( $f,
133 map => [ 5, 10],
134 profiles => [
135 {loadExtras => 0},
136 {loadExtras => 1},
137 ]);
138 first hash applies to frame index 5, and second - to frame index 10.
140 Null load requests
142 If it is desired to peek into image, reading type and dimensions only,
143 one should set 'noImageData' boolean value to 1. Using 'noImageData',
144 empty objects with read type are returned, and with extras 'width' and
145 'height' set to image dimensions. Example:
146 $x-> load( $f, noImageData => 1);
148 die "$@" unless $x;
149 print $x-> {extras}-> {width} , 'x' , $x-> {extras}-> {height}, 'x',
150 $x-> type & im::BPP, "\n";
151 Some information about image can be loaded even without frame loading -
153 if the codec provides such a functionality. This is the only request
154 that cannot be issued on a package:
155 $x-> load( $f, map => [], loadExtras => 1);
157 Since no frames are required to load, an empty array is returned upon
159 success and an array with one undefined value on failure.
160 Using Prima::Image descendants
162 If Prima needs to create a storage object, it is by default
163 Prima::Image, or a class name of an caller object, or a package the
164 request was issued on. This behavior can be altered using parameter
165 'className', which defines the class to be used for the frame.
166 my @x = Prima::Image-> load( $f,
168 map => [ 1..3],
169 className => 'Prima::Icon',
170 profiles => [
171 {},
172 { className => 'Prima::Image' },
173 {}
174 ],
175 In this example @x will be ( Icon, Image, Icon) upon success.
177 When loading to an Icon object, the default toolkit action is to build
179 the transparency mask based on image data. When it is not the desired
180 behavior, e.g., there is no explicit knowledge of image, but the image
181 may or may not contain transparency information, "iconUnmask" boolean
182 option can be used. When set to a "true" value, and the object is
183 "Prima::Icon" descendant, "Prima::Icon::autoMasking" is set to
184 "am::None" prior to the file loading. By default this options is turned
185 off.
186 Loading with progress indicator
188 Some codecs (PNG,TIFF,JPEG) can notify the caller as they read image
189 data. For this purpose, "Prima::Image" has two events, "onHeaderReady"
190 and "onDataReady". If either (or both) are present on image object that
191 is issuing load call, and the codec supports progressive loading, these
192 events are called. "onHeaderReady" is called when image header data is
193 acquired, and empty image with the dimensions and pixel type is
194 allocated. "onDataReady" is called whenever a part of image is ready
195 and is loaded in the memory of the object; the position and dimensions
196 of the loaded area is reported also. The format of the events is:
197 onHeaderReady $OBJECT
199 onDataReady $OBJECT, $X, $Y, $WIDTH, $HEIGHT
200 "onHeaderReady" is called only once, but "onDataReady" is called as
202 soon as new image data is available. To reduce frequency of these
203 calls, that otherwise would be issued on every scanline loaded, "load"
204 has parameter "eventDelay", a number of seconds, which limits event
205 rate. The default "eventDelay" is 0.1 .
206 The handling on "onDataReady" must be performed with care. First, the
208 image must be accessed read-only, which means no transformations with
209 image size and type are allowed. Currently there is no protection for
210 such actions ( because codec must perform these ), so a crash will most
211 surely issue. Second, loading and saving of images is not in general
212 reentrant, and although some codecs are reentrant, loading and saving
213 images inside image events is not recommended.
214 There are two techniques to display partial image as it loads. All of
216 these share overloading of "onHeaderReady" and "onDataReady". The
217 simpler is to call "put_image" from inside "onDataReady":
218 $i = Prima::Image-> new(
220 onDataReady => sub {
221 $progress_widget-> put_image( 0, 0, $i);
222 },
223 );
224 but that will most probably loads heavily underlying OS-dependent
226 conversion of image data to native display bitmap data. A more smarter,
227 but more complex solution is to copy loaded (and only loaded) bits to a
228 preexisting device bitmap:
229 $i = Prima::Image-> new(
231 onHeaderReady => sub {
232 $bitmap = Prima::DeviceBitmap-> new(
233 width => $i-> width,
234 height => $i-> height,
235 ));
236 },
237 onDataReady => sub {
238 my ( $i, $x, $y, $w, $h) = @_;
239 $bitmap-> put_image( $x, $y, $i-> extract( $x, $y, $w, $h));
240 },
241 );
242 The latter technique is used by "Prima::ImageViewer" when it is setup
244 to monitor image loading progress. See "watch_load_progress" in
245 Prima::ImageViewer for details.
246 Truncated files
248 By default, codecs are not specified whether they would fail on
249 premature end of file or omit the error and return truncated image.
250 "noIncomplete" boolean flag tells that a codec must always fail if the
251 image cannot be red in full. It is off by default. If indeed the codec
252 detected that the file was incomplete, it sets "truncated" boolean flag
253 in the "extras" profile, if "loadExtras" was requested.
254
256 Simple saving
257 Typical saving code will be:
258 die "$@" unless $x-> save( 'filename.duf');
260 Upon a single-frame invocation save returns 1 upon success an 0 on
262 failure. Save requests also can be performed with package syntax:
263 die "$@" unless Prima::Image-> save( 'filename.duf',
265 images => [ $x]);
266 Saving to a stream
268 Saving to a stream requires explicit "codecID" to be supplied. When an
269 image is loaded with "loadExtras", this field is always present on the
270 image object, and is an integer that selects image encoding format.
271 my @png_id =
273 map { $_-> {codecID} }
274 grep { $_-> {fileShortType} =~ /^png$/i }
275 @{ Prima::Image-> codecs };
276 die "No png codec installed" unless @png_id;
277 open FILE, "> a.png" or die "Cannot save:$!";
279 binmode FILE;
280 $image-> save( \*FILE, codecID => $png_id[0])
281 or die "Cannot save:$@";
282 Multiframe saving
284 In multiframe invocation save returns number of successfully saved
285 frames. File is erased though, if error occurred, even after some
286 successfully written frames.
287 die "$@" if scalar(@images) > Prima::Image-> save( $f,
289 images => \@images);
290 Saving extras information
292 All information, that is found in object hash reference 'extras', is
293 assumed to be saved as an extra information. It is a codec's own
294 business how it reacts on invalid and/or inacceptable information - but
295 typical behavior is that keys that were not recognized by the codec
296 just get ignored, and invalid values raise an error.
297 $x-> {extras}-> {comments} = 'Created by Prima';
299 $x-> save( $f);
300 Selecting a codec
302 Extras field 'codecID', the same one that is defined after load
303 requests, selects explicitly a codec for an image to handle. If the
304 codec selected is incapable of saving an error is returned. Selecting a
305 codec is only possible with the object-driven syntax, and this
306 information is never extracted from objects but passed to 'images'
307 array instead.
308 $x-> {extras}-> {codecID} = 1;
310 $x-> save( $f);
311 Actual correspondence between codecs and their indices is described
313 latter.
314 NB - if codecID is not given, codec is selected by the file extension.
316 Type conversion
318 Codecs usually are incapable of saving images in all formats, so Prima
319 either converts an image to an appropriate format or signals an error.
320 This behavior is governed by profile key 'autoConvert', which is 1 by
321 default. 'autoConvert' can be present in image 'extras' structures.
322 With autoConvert set it is guaranteed that image will be saved, but
323 original image information may be lost. With autoConvert unset, no
324 information will be lost, but Prima may signal an error. Therefore
325 general-purpose save routines should be planned carefully. As an
326 example the Prima::ImageDialog::SaveImageDialog code might be useful.
327 When the conversion takes place, Image property 'conversion' is used
329 for selection of an error distribution algorithm, if down-sampling is
330 required.
331 Appending frames to an existing file
333 This functionality is under design, but the common outlines are already
334 set. Profile key 'append' ( 0 by default ) triggers this behavior - if
335 it is set, then an append attempt is made.
336
338 Prima provides single function, Prima::Image-> codecs, which returns an
339 anonymous array of hashes, where every hash entry corresponds to a
340 registered codec. 'codecID' parameter on load and save requests is
341 actually an index in this array. Indexes for a codecs registered once
342 never change, so it is safe to manipulate these numbers within single
343 program run.
344 Codec information that is contained in these hashes is divided into
346 following parameters:
347 codecID
349 Unique integer value for a codec, same as index of the codec entry
350 in results of "Prima::Image->codecs";
351 name
353 codec full name, string
354 vendor
356 codec vendor, string
357 versionMajor and versionMinor
359 usually underlying library versions, integers
360 fileExtensions
362 array of strings, with file extensions that are typical to a codec.
363 example: ['tif', 'tiff']
364 fileType
366 Description of a type of a file, that codec is designed to work
367 with. String.
368 fileShortType
370 Short description of a type of a file, that codec is designed to
371 work with. ( short means 3-4 characters ). String.
372 featuresSupported
374 Array of strings, with some features description that a codec
375 supports - usually codecs implement only a part of file format
376 specification, so it is always interesting to know, what part it
377 is.
378 module and package
380 Specify a perl module, usually inside Prima/Image directory into
381 Prima distribution, and a package inside the module. The package
382 contains some specific functions for work with codec-specific
383 parameters. Current implementation defines only ::save_dialog()
384 function, that returns a dialog that allows to change these
385 parameters. See Prima::ImageDialog::SaveImageDialog for details.
386 Strings, undefined if empty.
387 canLoad
389 1 if a codec can load images, 0 if not
390 canLoadStream
392 1 if a codec can load images from streams, 0 otherwise
393 canLoadMultiple
395 1 if a codec can handle multiframe load requests and load frames
396 with index more than zero. 0 if not.
397 canSave
399 1 if a codec can save images, 0 if not.
400 canSaveStream
402 1 if a codec can save images to streams, 0 otherwise
403 canSaveMultiple
405 Set if a codec can save more that one frame
406 canAppend
408 Set if a codec can append frames to an exising file
409 types
411 Array of integers - each is a combination of im:: flags, an image
412 type, which a codec is capable of saving. First type in list is a
413 default one; if image type that to be saved is not in that list,
414 the image will be converted to this default type.
415 loadInput
417 Hash, where keys are those that are accepted by Prima::Image->
418 load, and values are default values for these keys.
419 loadOutput
421 Array of strings, each of those is a name of extra information
422 entry in 'extras' hash.
423 saveInput
425 Hash, where keys are those that are accepted by Prima::Image->
426 save, and values are default values for these keys.
427
429 This section describes parameters accepted and data returned by
430 "Prima::Image::load"
431 Common
433 Loading parameters
434 className STRING
436 When loading more than one image, this string is used to create
437 instances of image containers. By default the calling class is used
438 (i.e. "Prima::Image" or "Prima::Icon").
439 eventDelay INT
441 Specifies "onDataReady" event granularity in microseconds, if image
442 codec is capable of triggering this event.
443 Default: 100
445 iconUnmask BOOL
447 If set, "Prima::Icon::autoMasking" is set to "am::None" prior to
448 the file loading.
449 Default: false. Only actual for "Prima::Icon" loading.
451 index INT
453 When loading from a multiframe file, selects the frame index to
454 load.
455 Default: 0
457 map [INT]
459 When loading from a multiframe file, selects set of frame indexes
460 to load.
461 Default: undef
463 loadExtras BOOL
465 If set, all available extra information will be stored in
466 "{extras}" hash on the loaded object.
467 Default: false
469 loadAll BOOL
471 When loading from a multiframe file, selects that all frames are to
472 be loaded
473 Default: false
475 noImageData BOOL
477 When set, neither image data is not loaded, nor image dimensions
478 are changed (newly created images have size of 1x1). Instead,
479 "{extras}" contains "width" and "height" integers.
480 Default: false
482 noIncomplete BOOL
484 Affects the action when image is incomplete, truncated, etc. If
485 set, signals an error. Otherwise no error is signalled and whatever
486 data could be recovered from the image are returned, and
487 "truncated" flag is set.
488 Default: false
490 profiles [HASH]
492 Array of hashes passed down to each frame in multiframe loads. Each
493 frame load request will be passed an individual hash, a result of
494 hash join of all profiles passed to "Image::load" and the nth hash
495 in the array.
496 wantFrames BOOL
498 Affects how the number of frames in a file is reported in "frames"
499 flag. If set, always scans the file for exact number. Otherwise it
500 is up to the codec to do that.
501 Default: false
503 See also: frames.
505 Load output
507 codecID INT
509 Indicates the internal codec ID used to load the image. Can be used
510 for "Image::save".
511 frames INT
513 If set to a positive integer, indicates number of frames in a file.
514 Otherwise signals that there are frames, but codec needs an
515 expensive scan to calculate the frames (and "wantFrames" set).
516 height INT
518 When "noImageData" is in action, contains image height.
519 truncated BOOL
521 When "noIncomplete" is in action, is set if image was truncated.
522 width INT
524 When "noImageData" is in action, contains image width.
525 Saving parameters
527 autoConvert BOOL
529 Affects the action when image cannot be stored in file format in
530 its existing pixel format. If set, the system tries to convert
531 image into a pixel format understood by the selected codec. Fails
532 otherwise.
533 Default: true
535 codecID INT
537 Overrides codec selection based on filename extension.
538 Default: undef
540 BMP codec
542 BMP, the bitmap codec is not depended on external libraries and is
543 always available.
544 BitDepth INT
546 Original bit depth, may differ from "Image::bpp".
547 Not valid as a saving parameter.
549 Compression STRING
551 Bitmap compressing method.
552 Not valid as a saving parameter.
554 HotSpotX, HotSpotY INT
556 If loading from cursor file, contains pointer hotspot coordinates
557 ImportantColors INT
559 Minimal number of colors needed to display the image
560 OS2 BOOL
562 Set when loading OS/2 bitmap
563 XResolution, YResolution INT
565 Image resolution in PPM
566 X11 codec
568 X11, the X Consortium data file codec may depend on external libraries,
569 but is implement internally if these are not found, and is thus always
570 available.
571 hotSpotX, hotSpotY INT
573 Contains pointer hotspot coordinates, if any
574 XPM codec
576 extensions HASH
577 Set of xpm-specific extension strings. Cannot be used for saving.
578 hintsComment, colorsComment, pixelsComment STRING
580 Contains comments to different sections
581 hotSpotX, hotSpotY INT
583 Contains pointer hotspot coordinates
584 transparentColors [COLOR]
586 Array or transparent colors. Cannot be used for saving.
587 JPEG codec
589 Load parameteres
590 exifTransform none|auto|wipe
592 If set to "auto" or "wipe", tries to detect whether there is are
593 any exif tags hinting that the image has to be rotated and/or
594 mirrored. If found, applies the transformation accordingly.
595 When set to "wipe", in addition to that, removes the exif tags so
597 that subsequent image save won't result in transformed images with
598 exifs tags still present.
599 This parameter requires "loadExtras" flag set, because exif tags
601 are stored in extra JPEG data.
602 Load output and save input
604 appdata [STRING]
606 Array of raw binary strings found in extra JPEG data.
607 comment STRING
609 Any comment text found in file.
610 progressive BOOL
612 If set, produces a progressively encoded JPEG file.
613 Default: 0
615 Only used for saving.
617 quality INT
619 JPEG quality, 1-100.
620 Default: 75
622 Only used for saving.
624 PNG codec
626 Load input
627 background COLOR
629 When PNG file contains alpha channel, and "alpha" is set to
630 "blend", this color is used to blend the background. If set to
631 "clInvalid", default PNG library background color is used.
632 Default: clInvalid
634 Not applicable "Prima::Icon".
636 blending BOOLEAN = 1
638 Affects how to treat aplha channel bits, if any.
639 If set, mixes the alpha channel with "background" color in case if
641 loading to an image, or premultiplies color bits (either data or
642 palette) with alpha, if loading to icon. Note that saving back the
643 object will result in different image, but the object is ready to
644 be displayed immediately.
645 If unset, color and eventual alpha bits, if loaded to an icon, will
647 not be affected in any way. Note that saving back the object will
648 result in the same image, but the object is not ready to be
649 displayed immediately. See also: "premultiply_alpha" in
650 Prima::Image.
651 gamma REAL
653 Override gamma value applied to the loaded image
654 Default: 0.45455
656 screen_gamma REAL
658 Current gamma value for the operating system, if specified.
659 Default: 2.2
661 Load output and save input
663 background COLOR
665 Default PNG library background color
666 Default: clInvalid, which means PNG library default
668 gamma REAL
670 Gamma value found in file.
671 Default: 0.45455
673 iccp_name, iccp_profile STRING
675 Embedded ICC color profiles in raw format
676 Default: "unspecified" and "".
678 interlaced BOOL
680 If set, PNG file is interlaced
681 Default: 0
683 mng_datastream BOOL
685 If set, file contains a MNG datastream
686 Default: 0
688 offset_x, offset_y INT
690 Positive offset from the left edge of the screen to offset_x and
691 the positive offset from the left edge of the screen to offset_y
692 Default: 0
694 offset_dimension pixel|micrometer
696 Offset units
697 Default: pixel
699 render_intent none|saturation|perceptual|relative|absolute
701 See PNG docs.
702 Default: none
704 resolution_x, resolution_y INT
706 Image resolution
707 Default: 0
709 resolution_dimension meter|unknown
711 Image resolution units
712 Default: meter
714 scale_x, scale_y
716 Image scale factors
717 Default: 1
719 scale_unit meter|radian|unknown
721 Image scale factor units
722 Default: unknown
724 text HASH
726 Free-text comments found in the file
727 Default: "{}"
729 transparent_colors [COLOR], transparency_table [INT]
731 When image contains transparent colors, returns either array of
732 palette indexes ("transparency_table") in 0-255 range, for paletted
733 images. Or an array of colors in RGB form for 24-bit images
734 ("transparent_colors").
735 Not applicable for save.
737 Note: support for transparency is not symmetric; codec cannot
739 automatically save the transparency info read from PNG files. See
740 "transparent_color" and "transparent_color_index" for manual save
741 of one transparent color.
742 transparent_color COLOR
744 One transparent color value for 24-bit PNG images.
745 Default value: clInvalid (i.e. none)
747 Not applicable for load.
749 transparent_color_index INT
751 One transparent color value, as palette index for 8- or less- bit
752 PNG images.
753 Default value: -1 (i.e. none)
755 Not applicable for load.
757 TIFF codec
759 Load input
760 MinIsWhite BOOL
762 Automatically invert "PHOTOMETRIC_MINISWHITE" images
763 Default: 1
765 Fax BOOL
767 If set, converts 1-bit grayscale with ratio 2:1 into 2-bit
768 grayscale (alglorithm also known as faxpect).
769 Default: 0
771 Load output
773 Photometric STRING
775 TIFF "PHOTOMETRIC_XXX" constant. One of:
776 MinIsWhite
778 MinIsBlack
779 Palette
780 YCbCr
781 RGB
782 LogL
783 LogLUV
784 Separated
785 MASK
786 CIELAB
787 DEPTH
788 Unknown
789 BitsPerSample INT
791 Bits used to represent a single sample, 1-64
792 SamplesPerPixel INT
794 Number of samples per pixel, 1-4. F.ex. most images have 1 sample.
795 Planar TIFFs may split low and high bytes in 2 samples. RGB has 3
796 samples, YCbCr and RGBA has 4.
797 PlanarConfig contiguous|separate
799 "separate" images split individual samples or components (f.ex. R
800 and G and B) into individual planes. "contiguous" mix sample bytes
801 one after another.
802 SampleFormat STRING
804 Pixel sample format, one of:
805 unsigned integer
807 signed integer
808 floating point
809 untyped data
810 complex signed int
811 complex floating point
812 Tiled BOOL
814 If set, TIFF is tiled
815 Faxpect BOOL
817 When "Fax" option set set to "true", and indeed the image was
818 converted from 1 to 2 bits, this parameter will be set to signal
819 this.
820 CompressionType STRING
822 Compression algorithm used for reading TIFF. One of:
823 NONE
825 CCITTRLE
826 CCITTFAX3
827 CCITTFAX4
828 LZW
829 OJPEG
830 JPEG
831 NEXT
832 CCITTRLEW
833 PACKBITS
834 THUNDERSCAN
835 IT8CTPAD
836 IT8LW
837 IT8MP
838 IT8BL
839 PIXARFILM
840 PIXARLOG
841 DEFLATE
842 ADOBE_DEFLATE
843 DCS
844 JBIG
845 SGILOG
846 SGILOG24
847 Save input
849 Compression STRING
851 Same values as in "CompressionType". Different names are used to
852 avoid implicit but impossible compression selection, because
853 tibtiff can decompress many types, but compress only a few.
854 Load output and save input
856 generic strings
858 The following keys have no specific meanings for Prima, but are
859 both recognized for loading and saving:
860 Artist
862 Copyright
863 DateTime
864 DocumentName
865 HostComputer
866 ImageDescription
867 Make
868 Model
869 PageName
870 PageNumber
871 PageNumber2
872 PageNumber, PageNumber2 INT
874 Default: 1
875 ResolutionUnit inch|centimeter|none
877 Default: none
878 Software
880 Default: Prima
881 XPosition, YPosition INT
883 Default: 0
884 XResolution, YResolution INT
886 Default: 1200
887 GIF codec
889 For GIF animation see Prima::Image::AnimateGIF.
890 The following load output and save input keys are recognized:
892 comment STRING
894 GIF comment text
895 delayTime INT
897 Delay in hundredth of a second between frames
898 Default: 1
900 disposalMethod INT
902 Animation frame disposal method
903 DISPOSE_NOT_SPECIFIED = 0; # Leave frame, let new frame draw on top
905 DISPOSE_KEEP = 1; # Leave frame, let new frame draw on top
906 DISPOSE_CLEAR = 2; # Clear the frame's area, revealing bg
907 DISPOSE_RESTORE_PREVIOUS = 3; # Restore the previous (composited) frame
908 Default: 0
910 interlaced BOOL
912 If set, GIF is interlaced
913 Default: 0
915 left, top INT
917 Frame offset in pixels
918 Default: 0
920 loopCount INT
922 How many times the GIF animation loops. 0 means indefinite.
923 Default: 1
925 screenBackGroundColor COLOR
927 GIF screen background color
928 Default: 0
930 screenColorResolution INT
932 Default: 256
933 screenWidth, screenHeight INT
935 Default: -1, i.e. use image width and height
936 screenPalette [INT]
938 Default: 0,0,0,255,255,255
939 transparentColorIndex INT
941 Index of GIF transparent color
942 Default: 0
944 userInput INT
946 User input flag
947 Default: 0
949
951 Dmitry Karasik, <dmitry@karasik.eu.org>.
952
954 Prima, Prima::Image, Prima::codecs
955perl v5.28.1 2019-02-02 pod::Prima::image-load(3)