Rob Wu 01f03fe393 Optimize PNG compression in SVG backend on Node.js ... Use the environment's zlib implementation if available to get reasonably-sized SVG files when an XObject image is converted to PNG. The generated PNG is not optimal because we do not use a PNG predictor. Futher, when our SVG backend is run in a browser, the generated PNG images will still be unnecessarily large (though the use of blob:-URLs when available should reduce the impact on memory usage). If we want to optimize PNG images in browsers too, we can either try to use a DEFLATE library such as pako, or re-use our XObject image painting logic in src/display/canvas.js. This potential improvement is not implemented by this commit Tested with: - Node.js 8.1.3 (uses zlib) - Node.js 0.11.12 (uses zlib) - Node.js 0.10.48 (falls back to inferior existing implementation). - Chrome 59.0.3071.86 - Firefox 54.0 Tests: Unit test on Node.js: ``` $ gulp lib $ JASMINE_CONFIG_PATH=test/unit/clitests.json node ./node_modules/.bin/jasmine --filter=SVG ``` Unit test in browser: Run `gulp server` and open http://localhost:8888/test/unit/unit_test.html?spec=SVGGraphics To verify that the patch works as desired, ``` $ node examples/node/pdf2svg.js test/pdfs/xobject-image.pdf $ du -b svgdump/xobject-image-1.svg # ^ Calculates the file size. Confirm that the size is small # (784 instead of 80664 bytes). ```		2017-07-10 18:56:57 +02:00
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annotation_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
api_spec.js	Preventing from using the same canvas for multiple render()	2017-06-12 16:33:49 -05:00
bidi_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
cff_parser_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
clitests.json	Optimize PNG compression in SVG backend on Node.js	2017-07-10 18:56:57 +02:00
cmap_spec.js	Enable the object-shorthand ESLint rule	2017-04-30 11:13:34 +02:00
crypto_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
custom_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
display_svg_spec.js	Optimize PNG compression in SVG backend on Node.js	2017-07-10 18:56:57 +02:00
document_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
dom_utils_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
evaluator_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
fonts_spec.js	Enable the object-shorthand ESLint rule	2017-04-30 11:13:34 +02:00
function_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
jasmine-boot.js	Optimize PNG compression in SVG backend on Node.js	2017-07-10 18:56:57 +02:00
metadata_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
murmurhash3_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
network_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
parser_spec.js	Ignore line-breaks between operator and digit in Lexer.getNumber	2017-05-02 20:59:42 +02:00
primitives_spec.js	Enable the object-shorthand ESLint rule	2017-04-30 11:13:34 +02:00
stream_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
test_utils.js	Adds additional parameter so background color of canvas can be set	2017-05-17 17:06:44 +01:00
testreporter.js	Enable the object-shorthand ESLint rule	2017-04-30 11:13:34 +02:00
type1_parser_spec.js	Fix inconsistent spacing and trailing commas in objects in test/ files, so we can enable the comma-dangle and object-curly-spacing ESLint rules later on	2017-06-02 13:04:04 +02:00
ui_utils_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
unicode_spec.js	Convert the files in the /test/unit folder to ES6 modules	2017-04-30 00:34:02 +02:00
unit_test.html	Replaces RequireJS to SystemJS.	2017-02-27 08:32:39 -06:00
util_spec.js	Added sendWithStream method in MessageHandler.	2017-06-07 21:05:27 +05:30
util_stream_spec.js	Added sendWithStream method in MessageHandler.	2017-06-07 21:05:27 +05:30