createCanvas()create a new Canvas element.
createImageData(width, height)create a new ImageData object.
isImage(object)tests for Image object.
isCanvas(object)tests for Canvas object.
isContext(object)tests for CanvasRenderingContext2D object.
isImageData(object)tests for ImageData object.
isImageType(object)tests for any of the above.
toImageData(object)converts image type object to a new ImageData object.
equal(a, b, tolerance)tests image type objects for equality; accepts tolerance in pixels.
diff(a, b, options)performs an image diff on a and b, returning a - b.
'top'to top-align the images when diffing different sizes.
noConflict()removes imagediff from the global space for compatibility, returning imagediff.
imageDataToPNG(imageData, outputFile, [callback])(node only) renders the imageData to png in outputFile with optional callback.
js-imagediff is available through the npm. It uses node-canvas which requires lib cairo to be installed.
Install js-imagediff with
npm install -g imagediff.
imagediff [-e|equal] [-t|tolerance VALUE] FILE_A FILE_Btests equality of two image files with an optional tolerance, printing 'true' or 'false'.
imagediff [-d|diff] FILE_A FILE_B OUTPUT_FILErenders an imagediff between two files, saving as the output file.
Canvas has been moved to an optional dependency for better browser and browserify support. If you see a message that the module cannot be found, please check
npm install first, incase there was indeed an issue installing it. This relates to https://github.com/HumbleSoftware/js-imagediff/issues/22. Please let me know if you have any issues on account of this, or know of a better work around.
toImageDiffEqual(expected, tolerance)expect a result to equal another image type.
toBeImageData()expect a result to be ImageData.
On failed tests,
toImageDiffEqual() will display the expected image, the actual image and the imagediff of the two letting you easily spot mistakes.
To use matchers:
If you are using js-imagediff pelase drop us a line and let us know what you are doing with it.
imageDataToPNGmethod for node environments.
createCanvasfor symmetry with
toImageDiffEqual()matcher and non Node types - will no convert ImageData and contexts to Canvas elements for display.