diff_image

Description:

diff image

diff_image #
A Dart Package to get the % difference between two images of the same width and height.
diff_image is a Dart version of this with changes on visualization and , you guessed it, the language.
Example #
A simple usage example:
import 'package:diff_image/diff_image.dart';
import 'package:image/image.dart';

final FIRST_IMAGE = 'https://raw.githubusercontent.com/nicolashahn/diffimg/master/images/mario-circle-cs.png';
final SECOND_IMAGE = 'https://raw.githubusercontent.com/nicolashahn/diffimg/master/images/mario-circle-node.png';

void foo() async {
try {
var diff = await DiffImage.compareFromUrl(
FIRST_IMAGE,
SECOND_IMAGE,
);
print('The difference between images is: ${diff.value} %');
} catch(e) {
print(e);
}
}

void goo(Image first, Image second) {
try {
var diff = DiffImage.compareFromMemory(
first,
second,
);
print('The difference between images is: ${diff.diffValue} %');
} catch(e) {
print(e);
}
}

main() {
foo();
/*These can be obtained with any method*/
Image first;
Image second;
// Here is posible to manipulate both images before passing them
// to the function.
goo(first, second);
}
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A more detailed example can be found here
Features #

Currently there is support for comparing images fetched from urls and from memory or storage.
The compareFromUrl definition is:

static Future<DiffImgResult> compareFromUrl(
dynamic firstImgSrc,
dynamic secondImgSrc, {
bool asPercentage = true,
bool ignoreAlpha = true,
}) async{...}
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And the compareFromMemory definition is:

static DiffImgResult compareFromMemory(
Image firstImg,
Image secondImg, {
bool asPercentage = true,
bool ignoreAlpha = true,
}) {...}
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where:

ignoreAlpha allows to decide whether to take alpha from RGBA into account for the calculation
asPercentage set the format of the output (as percentage or between 0-1)

Both methods return an DiffImgResult, a model which contains two elements: An image showing the differences between both images and the numeric value representing the difference (as percentage or not).

A function called saveDiffImg which saves a png showing the differences between firstImg and secondImg (currently not available on Dart Web).

Sample Results #
First Image #

Second Image #

Difference Percentage #
With Alpha : 35.67169421487167 %
Without Alpha : 34.83905183744361 %
Difference Image #

Suggestions and bugs #
Please file feature requests, suggestions and bugs at the issue tracker.