Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Fixes #34, adding options.ligthness to diff (Diff swallows black color i... #51

Closed
wants to merge 1 commit into from
Closed

Fixes #34, adding options.ligthness to diff (Diff swallows black color i... #51

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
35 changes: 27 additions & 8 deletions imagediff.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -194,10 +194,12 @@
i, j, k, v;

for (i = 0; i < length; i += 4) {
cData[i] = Math.abs(aData[i] - bData[i]);
cData[i+1] = Math.abs(aData[i+1] - bData[i+1]);
cData[i+2] = Math.abs(aData[i+2] - bData[i+2]);
cData[i+3] = Math.abs(255 - Math.abs(aData[i+3] - bData[i+3]));
// rgbIndex: r = 0, g = 1, b = 2
for (var rgbIndex = 0; rgbIndex < 3 ; rgbIndex++) {
cData[i+rgbIndex] = diffColorValue(aData[i+rgbIndex], bData[i+rgbIndex], options);
}
// Disables alpha transparency for clearly visible diff pixels:
cData[i+3] = 255;
}

return c;
Expand Down Expand Up @@ -231,7 +233,6 @@
cData[i+0] = aData[j+0]; // r
cData[i+1] = aData[j+1]; // g
cData[i+2] = aData[j+2]; // b
// cData[i+3] = aData[j+3]; // a
}
}

Expand All @@ -241,9 +242,11 @@
for (column = b.width; column--;) {
i = 4 * ((row + rowOffset) * width + (column + columnOffset));
j = 4 * (row * b.width + column);
cData[i+0] = Math.abs(cData[i+0] - bData[j+0]); // r
cData[i+1] = Math.abs(cData[i+1] - bData[j+1]); // g
cData[i+2] = Math.abs(cData[i+2] - bData[j+2]); // b

// rgbIndex: r = 0, g = 1, b = 2
for (var rgbIndex = 0; rgbIndex < 3 ; rgbIndex++) {
cData[i+rgbIndex] = diffColorValue(cData[i+rgbIndex], bData[j+rgbIndex], options);
}
}
}

Expand All @@ -261,6 +264,22 @@
return c;
}

/**
* Differentiates two colors values from their substraction.
* A black pixel means no difference (value 0), light value marks difference gap.
*
* Lightens the color difference with options.lightness (default +25).
* @see https://github.com/HumbleSoftware/js-imagediff/issues/34
*
* @returns {Number} a color value between 0 and 255.
*/
function diffColorValue(leftValue, rightValue, options) {
var lightness = 25;
if (options && options.lightness) lightness = options.lightness;
var diff = Math.abs(leftValue - rightValue);
if (diff > 0) diff += lightness;
return Math.min(diff, 255);
}

// Validation
function checkType () {
Expand Down
35 changes: 27 additions & 8 deletions js/imagediff.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -187,10 +187,12 @@
i, j, k, v;

for (i = 0; i < length; i += 4) {
cData[i] = Math.abs(aData[i] - bData[i]);
cData[i+1] = Math.abs(aData[i+1] - bData[i+1]);
cData[i+2] = Math.abs(aData[i+2] - bData[i+2]);
cData[i+3] = Math.abs(255 - Math.abs(aData[i+3] - bData[i+3]));
// rgbIndex: r = 0, g = 1, b = 2
for (var rgbIndex = 0; rgbIndex < 3 ; rgbIndex++) {
cData[i+rgbIndex] = diffColorValue(aData[i+rgbIndex], bData[i+rgbIndex], options);
}
// Disables alpha transparency for clearly visible diff pixels:
cData[i+3] = 255;
}

return c;
Expand Down Expand Up @@ -224,7 +226,6 @@
cData[i+0] = aData[j+0]; // r
cData[i+1] = aData[j+1]; // g
cData[i+2] = aData[j+2]; // b
// cData[i+3] = aData[j+3]; // a
}
}

Expand All @@ -234,9 +235,11 @@
for (column = b.width; column--;) {
i = 4 * ((row + rowOffset) * width + (column + columnOffset));
j = 4 * (row * b.width + column);
cData[i+0] = Math.abs(cData[i+0] - bData[j+0]); // r
cData[i+1] = Math.abs(cData[i+1] - bData[j+1]); // g
cData[i+2] = Math.abs(cData[i+2] - bData[j+2]); // b

// rgbIndex: r = 0, g = 1, b = 2
for (var rgbIndex = 0; rgbIndex < 3 ; rgbIndex++) {
cData[i+rgbIndex] = diffColorValue(cData[i+rgbIndex], bData[j+rgbIndex], options);
}
}
}

Expand All @@ -254,6 +257,22 @@
return c;
}

/**
* Differentiates two colors values from their substraction.
* A black pixel means no difference (value 0), light value marks difference gap.
*
* Lightens the color difference with options.lightness (default +25).
* @see https://github.com/HumbleSoftware/js-imagediff/issues/34
*
* @returns {Number} a color value between 0 and 255.
*/
function diffColorValue(leftValue, rightValue, options) {
var lightness = 25;
if (options && options.lightness) lightness = options.lightness;
var diff = Math.abs(leftValue - rightValue);
if (diff > 0) diff += lightness;
return Math.min(diff, 255);
}

// Validation
function checkType () {
Expand Down