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, $h));
240 },
241 );
242 The latter technique is used by "Prima::ImageViewer" when it is setup
244 to monitor image loading progress. See "watch_load_progress" in
245 Prima::ImageViewer for details.
246 Truncated files
248 By default, codecs are not specified whether they would fail on
249 premature end of file or omit the error and return truncated image.
250 "noIncomplete" boolean flag tells that a codec must always fail if the
251 image cannot be red in full. It is off by default. If indeed the codec
252 detected that the file was incomplete, it sets "truncated" error string
253 in the "extras" profile, if "loadExtras" was requested.
254
256 Simple saving
257 Typical saving code will be:
258 die "$@" 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 blending BOOLEAN = 1
436 Affects how to treat alpha channel bits, if any.
437 If set, mixes the alpha channel with background color in case if
439 loading to an image, or premultiplies color bits (either data or
440 palette) with alpha, if loading to icon. Note that saving back the
441 object will result in different image, but the object is ready to
442 be displayed immediately.
443 If unset, color and eventual alpha bits, if loaded to an icon, will
445 not be affected in any way. Note that saving back the object will
446 result in the same image, but the object is not ready to be
447 displayed immediately. See also: "premultiply_alpha" in
448 Prima::Image.
449 className STRING
451 When loading more than one image, this string is used to create
452 instances of image containers. By default the calling class is used
453 (i.e. "Prima::Image" or "Prima::Icon").
454 eventDelay INT
456 Specifies "onDataReady" event granularity in microseconds, if image
457 codec is capable of triggering this event.
458 Default: 100
460 iconUnmask BOOL
462 If set, "Prima::Icon::autoMasking" is set to "am::None" prior to
463 the file loading.
464 Default: false. Only actual for "Prima::Icon" loading.
466 index INT
468 When loading from a multiframe file, selects the frame index to
469 load.
470 Default: 0
472 map [INT]
474 When loading from a multiframe file, selects set of frame indexes
475 to load.
476 Default: undef
478 loadExtras BOOL
480 If set, all available extra information will be stored in
481 "{extras}" hash on the loaded object.
482 Default: false
484 loadAll BOOL
486 When loading from a multiframe file, selects that all frames are to
487 be loaded
488 Default: false
490 noImageData BOOL
492 When set, neither image data is not loaded, nor image dimensions
493 are changed (newly created images have size of 1x1). Instead,
494 "{extras}" contains "width" and "height" integers.
495 Default: false
497 noIncomplete BOOL
499 Affects the action when image is incomplete, truncated, etc. If
500 set, signals an error. Otherwise no error is signalled and whatever
501 data could be recovered from the image are returned, and
502 "truncated" flag is set.
503 Default: false
505 profiles [HASH]
507 Array of hashes passed down to each frame in multiframe loads. Each
508 frame load request will be passed an individual hash, a result of
509 hash join of all profiles passed to "Image::load" and the nth hash
510 in the array.
511 wantFrames BOOL
513 Affects how the number of frames in a file is reported in "frames"
514 flag. If set, always scans the file for exact number. Otherwise it
515 is up to the codec to do that.
516 Default: false
518 See also: frames.
520 Load output
522 codecID INT
524 Indicates the internal codec ID used to load the image. Can be used
525 for "Image::save".
526 frames INT
528 If set to a positive integer, indicates number of frames in a file.
529 Otherwise signals that there are frames, but codec needs an
530 expensive scan to calculate the frames (and "wantFrames" set).
531 height INT
533 When "noImageData" is in action, contains image height.
534 truncated BOOL
536 When "noIncomplete" is in action, is set if image was truncated.
537 The value is the error string.
538 width INT
540 When "noImageData" is in action, contains image width.
541 Saving parameters
543 autoConvert BOOL
545 Affects the action when image cannot be stored in file format in
546 its existing pixel format. If set, the system tries to convert
547 image into a pixel format understood by the selected codec. Fails
548 otherwise.
549 Default: true
551 codecID INT
553 Overrides codec selection based on filename extension.
554 Default: undef
556 BMP codec
558 BMP, the bitmap codec is not depended on external libraries and is
559 always available.
560 BitDepth INT
562 Original bit depth, may differ from "Image::bpp".
563 Not valid as a saving parameter.
565 Compression STRING
567 Bitmap compressing method.
568 Not valid as a saving parameter.
570 HotSpotX, HotSpotY INT
572 If loading from cursor file, contains pointer hotspot coordinates
573 ImportantColors INT
575 Minimal number of colors needed to display the image
576 OS2 BOOL
578 Set when loading OS/2 bitmap
579 XResolution, YResolution INT
581 Image resolution in PPM
582 X11 codec
584 X11, the X Consortium data file codec may depend on external libraries,
585 but is implement internally if these are not found, and is thus always
586 available.
587 hotSpotX, hotSpotY INT
589 Contains pointer hotspot coordinates, if any
590 XPM codec
592 extensions HASH
593 Set of xpm-specific extension strings. Cannot be used for saving.
594 hintsComment, colorsComment, pixelsComment STRING
596 Contains comments to different sections
597 hotSpotX, hotSpotY INT
599 Contains pointer hotspot coordinates
600 transparentColors [COLOR]
602 Array or transparent colors. Cannot be used for saving.
603 JPEG codec
605 Load parameteres
606 exifTransform none|auto|wipe
608 If set to "auto" or "wipe", tries to detect whether there is are
609 any exif tags hinting that the image has to be rotated and/or
610 mirrored. If found, applies the transformation accordingly.
611 When set to "wipe", in addition to that, removes the exif tags so
613 that subsequent image save won't result in transformed images with
614 exifs tags still present.
615 This parameter requires "loadExtras" flag set, because exif tags
617 are stored in extra JPEG data.
618 Load output and save input
620 appdata [STRING]
622 Array of raw binary strings found in extra JPEG data.
623 comment STRING
625 Any comment text found in file.
626 progressive BOOL
628 If set, produces a progressively encoded JPEG file.
629 Default: 0
631 Only used for saving.
633 quality INT
635 JPEG quality, 1-100.
636 Default: 75
638 Only used for saving.
640 PNG codec
642 Load input
643 background COLOR
645 When PNG file contains alpha channel, and "alpha" is set to
646 "blend", this color is used to blend the background. If set to
647 "clInvalid", default PNG library background color is used.
648 Default: clInvalid
650 Not applicable for "Prima::Icon".
652 gamma REAL
654 Override gamma value applied to the loaded image
655 Default: 0.45455
657 screen_gamma REAL
659 Current gamma value for the operating system, if specified.
660 Default: 2.2
662 Load output and save input
664 background COLOR
666 Default PNG library background color
667 Default: clInvalid, which means PNG library default
669 blendMethod blend|no_blend|unknown
671 Signals whether the new frame to be blended over the existing
672 animation, or replace it.
673 delayTime $milliseconds
675 Delay time between frames
676 default_frame BOOLEAN
678 When set, means that the first image is a "default" frame, a
679 special backward-compatibility image that is supposed to be
680 excluded from the animation sequence, to be displayed only when all
681 animation frames cannot be loaded for whatever reason.
682 disposalMethod none|background|restore|unknown
684 Signals whether the frame, before being replaced, is to be erased
685 by the background color, previous frame, or none.
686 gamma REAL
688 Gamma value found in file.
689 Default: 0.45455
691 hasAlpha BOOLEAN
693 If set, image contains alpha channel
694 iccp_name, iccp_profile STRING
696 Embedded ICC color profiles in raw format
697 Default: "unspecified" and "".
699 interlaced BOOL
701 If set, PNG file is interlaced
702 Default: 0
704 left INTEGER
706 Frame horizontal offset from the screen
707 loopCount INTEGER
709 How many times the animation sequence should run, or 0 for forever.
710 mng_datastream BOOL
712 If set, file contains a MNG datastream
713 Default: 0
715 offset_x, offset_y INT
717 Positive offset from the left edge of the screen to offset_x and
718 the positive offset from the left edge of the screen to offset_y
719 Default: 0
721 offset_dimension pixel|micrometer
723 Offset units
724 Default: pixel
726 render_intent none|saturation|perceptual|relative|absolute
728 See PNG docs.
729 Default: none
731 resolution_x, resolution_y INT
733 Image resolution
734 Default: 0
736 resolution_dimension meter|unknown
738 Image resolution units
739 Default: meter
741 scale_x, scale_y
743 Image scale factors
744 Default: 1
746 scale_unit meter|radian|unknown
748 Image scale factor units
749 Default: unknown
751 screenWidth, screenHeight INTEGER
753 text HASH
754 Free-text comments found in the file
755 Default: "{}"
757 top INTEGER
759 Frame vertical offset from the screen
760 transparency_table [INT]
762 When a paletted image contains transparent colors, returns array of
763 palette indexes ("transparency_table") in 0-255 range, where each
764 number is an alpha value.
765 Default value: empty array
767 transparent_color COLOR
769 One transparent color value for 24-bit PNG images.
770 Default value: clInvalid (i.e. none)
772 transparent_color_index INT
774 One transparent color value, as palette index for 8- or less- bit
775 PNG images.
776 Default value: -1 (i.e. none)
778 Not applicable for load.
780 TIFF codec
782 Load input
783 MinIsWhite BOOL
785 Automatically invert "PHOTOMETRIC_MINISWHITE" images
786 Default: 1
788 Fax BOOL
790 If set, converts 1-bit grayscale with ratio 2:1 into 2-bit
791 grayscale (alglorithm also known as faxpect).
792 Default: 0
794 Load output
796 Photometric STRING
798 TIFF "PHOTOMETRIC_XXX" constant. One of:
799 MinIsWhite
801 MinIsBlack
802 Palette
803 YCbCr
804 RGB
805 LogL
806 LogLUV
807 Separated
808 MASK
809 CIELAB
810 DEPTH
811 Unknown
812 BitsPerSample INT
814 Bits used to represent a single sample, 1-64
815 SamplesPerPixel INT
817 Number of samples per pixel, 1-4. F.ex. most images have 1 sample.
818 Planar TIFFs may split low and high bytes in 2 samples. RGB has 3
819 samples, YCbCr and RGBA has 4.
820 PlanarConfig contiguous|separate
822 "separate" images split individual samples or components (f.ex. R
823 and G and B) into individual planes. "contiguous" mix sample bytes
824 one after another.
825 SampleFormat STRING
827 Pixel sample format, one of:
828 unsigned integer
830 signed integer
831 floating point
832 untyped data
833 complex signed int
834 complex floating point
835 Tiled BOOL
837 If set, TIFF is tiled
838 Faxpect BOOL
840 When "Fax" option set set to "true", and indeed the image was
841 converted from 1 to 2 bits, this parameter will be set to signal
842 this.
843 CompressionType STRING
845 Compression algorithm used for reading TIFF. One of:
846 NONE
848 CCITTRLE
849 CCITTFAX3
850 CCITTFAX4
851 LZW
852 OJPEG
853 JPEG
854 NEXT
855 CCITTRLEW
856 PACKBITS
857 THUNDERSCAN
858 IT8CTPAD
859 IT8LW
860 IT8MP
861 IT8BL
862 PIXARFILM
863 PIXARLOG
864 DEFLATE
865 ADOBE_DEFLATE
866 DCS
867 JBIG
868 SGILOG
869 SGILOG24
870 Save input
872 Compression STRING
874 Same values as in "CompressionType". Different names are used to
875 avoid implicit but impossible compression selection, because
876 tibtiff can decompress many types, but compress only a few.
877 Load output and save input
879 generic strings
881 The following keys have no specific meanings for Prima, but are
882 both recognized for loading and saving:
883 Artist
885 Copyright
886 DateTime
887 DocumentName
888 HostComputer
889 ImageDescription
890 Make
891 Model
892 PageName
893 PageNumber
894 PageNumber2
895 PageNumber, PageNumber2 INT
897 Default: 1
898 ResolutionUnit inch|centimeter|none
900 Default: none
901 Software
903 Default: Prima
904 XPosition, YPosition INT
906 Default: 0
907 XResolution, YResolution INT
909 Default: 1200
910 GIF codec
912 For GIF animation see Prima::Image::Animate.
913 The following load output and save input keys are recognized:
915 comment STRING
917 GIF comment text
918 delayTime INT
920 Delay in hundredth of a second between frames
921 Default: 1
923 disposalMethod INT
925 Animation frame disposal method
926 DISPOSE_NOT_SPECIFIED = 0; # Leave frame, let new frame draw on top
928 DISPOSE_KEEP = 1; # Leave frame, let new frame draw on top
929 DISPOSE_CLEAR = 2; # Clear the frame's area, revealing bg
930 DISPOSE_RESTORE_PREVIOUS = 3; # Restore the previous (composited) frame
931 Default: 0
933 interlaced BOOL
935 If set, GIF is interlaced
936 Default: 0
938 left, top INT
940 Frame offset in pixels
941 Default: 0
943 loopCount INT
945 How many times the GIF animation loops. 0 means indefinite.
946 Default: 1
948 screenBackGroundColor COLOR
950 GIF screen background color
951 Default: 0
953 screenColorResolution INT
955 Default: 256
956 screenWidth, screenHeight INT
958 Default: -1, i.e. use image width and height
959 screenPalette [INT]
961 Default: 0,0,0,255,255,255
962 transparentColorIndex INT
964 Index of GIF transparent color
965 Default: 0
967 userInput INT
969 User input flag
970 Default: 0
972 WebP codec
974 Load input
975 background $ARGB_color
977 Integer constant encoded as ARGB, hints the background to be used
978 blendMethod blend|no_blend|unknown
980 Signals whether the new frame to be blended over the existing
981 animation, or replace it.
982 delayTime $milliseconds
984 Delay time between frames
985 disposalMethod none|background|unknown
987 Signals whether the frame, before being replaced, is to be erased
988 by the background color or not.
989 hasAlpha BOOLEAN
991 If set, image contains alpha channel
992 left INTEGER
994 Frame horizontal offset from the screen
995 loopCount INTEGER
997 How many times the animation sequence should run, or 0 for forever.
998 screenWidth INTEGER
1000 screenHeight INTEGER
1001 top INTEGER
1002 Frame vertical offset from the screen
1003 Save input
1005 WebP requires all images to have same dimensions. Also, saving the
1007 webp loading result might fail because loaded frames might only
1008 contains parts to be superimposed on each other, while saving requires
1009 always full frames. To convert webp loaded frames to something that can
1010 be saved later more-or-less identically, use
1011 "Prima::Image::webp::animation_to_frames" converter:
1012 use Prima qw(Image::webp);
1014 my @i = Prima::Icon->load('source.webp', loadAll => 1, loadExtras => 1) or die $@;
1015 @i = Prima::Image::webp::animation_to_frames(@i);
1016 die $@ if @i != Prima::Icon->save('target.webp', images => \@i);
1017 background $ARGB_color
1019 Integer constant encoded as ARGB, hints the background to be used
1020 compression lossless (default)|lossy|mixed
1022 delay $milliseconds
1023 filter_strength INTEGER
1024 Setting between 0 and 100, 0 means off.
1025 kmax INTEGER
1027 Min distance between key frames. Default is 9 for lossless
1028 compression, and 3 for lossy
1029 kmin INTEGER
1031 Max distance between key frames. Default is 17 for lossless
1032 compression, and 5 for lossy
1033 loopCount 0
1035 How many times the animation sequence should run, or 0 for forever.
1036 method INTEGER
1038 Compression method vs size, 0 (fast) to 6 (slow)
1039 minimize_size BOOLEAN
1041 Minimize output size (off by default)
1042 quality INTEGER
1044 Quality factor (0:small..100:big)
1045 thread_level BOOLEAN
1047 Use multi-threading if available (off by default)
1048
1050 Dmitry Karasik, <dmitry@karasik.eu.org>.
1051
1053 Prima, Prima::Image, Prima::codecs
1054perl v5.30.1 2020-01-30 pod::Prima::image-load(3)