Crisp up-scaled images for displays with 150% DPI scale factor (Firefox 74+)

Prevents blurry anti-aliased borders between picture sampling areas ("pixels").

Versión del día 17/06/2020. Echa un vistazo a la versión más reciente.

Tendrás que instalar una extensión para tu navegador como Tampermonkey, Greasemonkey o Violentmonkey si quieres utilizar este script.

You will need to install an extension such as Tampermonkey to install this script.

Tendrás que instalar una extensión como Tampermonkey o Violentmonkey para instalar este script.

Necesitarás instalar una extensión como Tampermonkey o Userscripts para instalar este script.

Tendrás que instalar una extensión como Tampermonkey antes de poder instalar este script.

Necesitarás instalar una extensión para administrar scripts de usuario si quieres instalar este script.

(Ya tengo un administrador de scripts de usuario, déjame instalarlo)

Advertisement:

Tendrás que instalar una extensión como Stylus antes de poder instalar este script.

Tendrás que instalar una extensión como Stylus antes de poder instalar este script.

Tendrás que instalar una extensión como Stylus antes de poder instalar este script.

Para poder instalar esto tendrás que instalar primero una extensión de estilos de usuario.

Para poder instalar esto tendrás que instalar primero una extensión de estilos de usuario.

Para poder instalar esto tendrás que instalar primero una extensión de estilos de usuario.

(Ya tengo un administrador de estilos de usuario, déjame instalarlo)

Advertisement:

/* ==UserStyle==
@name        Crisp up-scaled images for displays with 150% DPI scale factor (Firefox 74+)
@description Prevents blurry anti-aliased borders between picture sampling areas ("pixels").
@namespace   myfonj
@version     1.0.1
@license     CC0 - Public Domain
==/UserStyle== */

@-moz-document regexp(".*\\.(png|gif)(\\?.*)?(#.*)?$") {
/*
"DPI Zoom (scale) factor" can be obtained with JavaScript:

window.devicePixelRatio

for 150% DPI scale factor at page with 100% zoom level this should be 1.5

min zoom is 30 %
max zoom is 300 %

[ctrl] + [mouse wheel] modifies DPI consistently by +- 10 %.

[ctrl] + [+ / -] modifies DPI in prefefined values - powers of 10 % with two exceptions: 30, 50, *67*, 80, 90, 100, 110, 120, *133*, 150, 170, 200, 240, 300. Those exceptions and derived values [1] are not in scope of this stylesheet. 

[1] in theory combining wheel and keyboard zoom one could possibly get 30, *33*, *37*, 40, *43*, *47*, 50 (...) zoom factors.

a.k.a. resolution value for media query
this file expects "normal" scale factor to be *150%*
what normally causes ugly blurry "scaled down" images
this style undoes that scale so that image pixels are mapped to physical pixels and anti-aliasing is suppressed
producing crisp scaled image in "100% zoom" (then it is mapped to 2×2 pixels) and controls resizing with `transform` to maintain crispness and predictable dimension in most zoom levels.
*/


/*
100% page zoom
1 = __ monitor scale × __ transform scale to "undo"
1 = 1.25 × 0.8
1 = 1.5 × 0.6666666666666
1 = 2 × 0.5
strangemesses:
?? __ page zoom at monitor set to __ scale is matched by `(resolution: __)`
!! 90% 100% 0.895522445440292259dppx
OK 50% 100% 0.5dppx
OK 100% 125% 1.25dppx
!! 100% 175% 1.76470595598220835dppx

centering crisp image of odd dimesion would produce unwanted "notch" from rounding
drawbacks: 
- zooming is funky: apparently "zoom" is done by ajdusting DPI factor, so sometimes some of our rules hits

[width][height] = image fits viewport
*/


@media
(resolution: 0.75dppx),
(resolution: 0.8955223880597015dppx),
(resolution: 1.0526315789473684dppx),
(resolution: 1.2dppx),
(resolution: 1.3636363636363635dppx),
(resolution: 1.50dppx),
(resolution: 1.6666666666666667dppx),
(resolution: 1.8181818181818181dppx),
(resolution: 1.935483870967742dppx),
(resolution: 2.0689655172413794dppx),
(resolution: 2.00dppx),
(resolution: 2.2222222222222223dppx),
(resolution: 2.4dppx),
(resolution: 2.50dppx),
(resolution: 2.727272727272727dppx),
(resolution: 2.857142857142857dppx),
(resolution: 2.857142857142857dppx),
(resolution: 3.00dppx),
(resolution: 3.1578947368421053dppx),
(resolution: 3.3333333333333335dppx),
(resolution: 3.5294117647058822dppx),
(resolution: 3.3333333333333335dppx),
(resolution: 3.5294117647058822dppx), /* twice ?! */
(resolution: 3.75dppx),
(resolution: 4.00dppx),
(resolution: 4.285714285714286dppx),
(resolution: 4.615384615384615dppx)
{
	html>body>img:only-child:not([width]):not([height]) {
		image-rendering: var(--image-rendering, -moz-crisp-edges);
		transform: scale(calc(var(--scale-to) / var(--dppx)));
		transform-origin: top left;
		margin: 0;
		top: auto;
		bottom: auto;
		left: auto;
		right: auto;
	}
	/*
	debug
	*/
	html::after {
		content: var(--dppx-debug) ' dppx; ' var(--zoom-debug) ' zoom; scale: ' var(--scale-to-debug) '×';
		position: fixed;
		top: 0;
		right: 0;
		color: #ccc;
		background-color: rgba(0,0,0,0.5);
		font-size: calc(1 / var(--dppx) * 1.9rem);
		/*
		this effectively cancels page zoom
		so the physical text size remains the same
		like using viewport units, but without viewport
		accessibility warning
		never ever do this
		*/
	}
}

@media (resolution: 0.75dppx) {
	:root {
		--zoom-debug: '50%';
		--dppx: 0.75;
		--dppx-debug: '0.75';
		--scale-to: 0.0625;
		--scale-to-debug: '0.0625';
		--image-rendering: auto;
	}
}

@media (resolution: 0.8955223880597015dppx) {
	:root {
		--zoom-debug: '60%';
		--dppx: 0.8955223880597015;
		--dppx-debug: '0.8955223880597015';
		--scale-to: 0.125;
		--scale-to-debug: '0.125';
		--image-rendering: auto;
	}
}

@media (resolution: 1.0526315789473684dppx) {
	:root {
		--zoom-debug: '70%';
		--dppx: 1.0526315789473684;
		--dppx-debug: '1.0526315789473684';
		--scale-to: 0.25;
		--scale-to-debug: '0.25';
		--image-rendering: auto;
	}
}

@media (resolution: 1.2dppx) {
	:root {
		--zoom-debug: '80%';
		--dppx: 1.2;
		--dppx-debug: '1.2';
		--scale-to: 0.5;
		--scale-to-debug: '0.5';
		--image-rendering: auto;
	}
}

@media (resolution: 1.2dppx) {
	:root {
		--zoom-debug: '80%';
		--dppx: 1.2;
		--dppx-debug: '1.2';
		--scale-to: 0.5;
		--scale-to-debug: '0.5';
		--image-rendering: auto;
	}
}

@media (resolution: 1.3636363636363635dppx) {
	:root {
		--zoom-debug: '90%';
		--dppx: 1.3636363636363635;
		--dppx-debug: '1.3636363636363635';
		--scale-to: 1;
		--scale-to-debug: '1';
	}
}

@media (resolution: 1.50dppx) {
	:root {
		--zoom-debug: '100%';
		--dppx: 1.50;
		--dppx-debug: '1.50';
		--scale-to: 2;
		--scale-to-debug: '2';
	}
}

@media (resolution: 1.6666666666666667dppx) {
	:root {
		--zoom-debug: '110%';
		--dppx: 1.6666666666666667;
		--dppx-debug: '1.6666666666666667';
		--scale-to: 3;
		--scale-to-debug: '3';
	}
}

@media (resolution: 1.8181818181818181dppx) {
	:root {
		--zoom-debug: '120%';
		--dppx: 1.8181818181818181;
		--dppx-debug: '1.8181818181818181';
		--scale-to: 4;
		--scale-to-debug: '4';
	}
}

@media (resolution: 1.935483870967742dppx) {
	:root {
		--zoom-debug: '130%';
		--dppx: 1.935483870967742;
		--dppx-debug: '1.935483870967742';
		--scale-to: 5;
		--scale-to-debug: '5';
	}
}

@media (resolution: 2.00dppx) {
	:root {
		--zoom-debug: '133%';
		--dppx: 2.00;
		--dppx-debug: '2.00';
		--scale-to: 6;
		--scale-to-debug: '6';
	}
}

@media (resolution: 2.0689655172413794dppx) {
	:root {
		--zoom-debug: '140%';
		--dppx: 2.0689655172413794;
		--dppx-debug: '2.0689655172413794';
		--scale-to: 7;
		--scale-to-debug: '7';
	}
}

@media (resolution: 2.2222222222222223dppx) {
	:root {
		--zoom-debug: '150%';
		--dppx: 2.2222222222222223;
		--dppx-debug: '2.2222222222222223';
		--scale-to: 8;
		--scale-to-debug: '8';
	}
}

@media (resolution: 2.4dppx) {
	:root {
		--zoom-debug: '160%';
		--dppx: 2.4;
		--dppx-debug: '2.4';
		--scale-to: 9;
		--scale-to-debug: '9';
	}
}

@media (resolution: 2.50dppx) {
	:root {
		--zoom-debug: '170%';
		--dppx: 2.50;
		--dppx-debug: '2.50';
		--scale-to: 10;
		--scale-to-debug: '10';
	}
}

@media (resolution: 2.727272727272727dppx) {
	:root {
		--zoom-debug: '180%';
		--dppx: 2.727272727272727;
		--dppx-debug: '2.727272727272727';
		--scale-to: 11;
		--scale-to-debug: '11';
	}
}

@media (resolution: 2.857142857142857dppx) {
	:root {
		--zoom-debug: '190%';
		--dppx: 2.857142857142857;
		--dppx-debug: '2.857142857142857';
		--scale-to: 12;
		--scale-to-debug: '12';
	}
}

@media (resolution: 3.00dppx) {
	:root {
		--zoom-debug: '200%';
		--dppx: 3.00;
		--dppx-debug: '3.00';
		--scale-to: 13;
		--scale-to-debug: '13';
	}
}

@media (resolution: 3.1578947368421053dppx) {
	:root {
		--zoom-debug: '210%';
		--dppx: 3.1578947368421053;
		--dppx-debug: '3.1578947368421053';
		--scale-to: 14;
		--scale-to-debug: '14';
	}
}

@media (resolution: 3.3333333333333335dppx) {
	:root {
		--zoom-debug: '220%';
		--dppx: 3.3333333333333335;
		--dppx-debug: '3.3333333333333335';
		--scale-to: 15;
		--scale-to-debug: '15';
	}
}

@media (resolution: 3.5294117647058822dppx) {
	:root {
		--zoom-debug: '230% or 240%';
/*
for some mysterious reason both zoom levels matches this resolution
*/
		--dppx: 3.5294117647058822;
		--dppx-debug: '3.5294117647058822';
		--scale-to: 16;
		--scale-to-debug: '16';
	}
}

@media (resolution: 3.75dppx) {
	:root {
		--zoom-debug: '250%';
		--dppx: 3.75;
		--dppx-debug: '3.75';
		--scale-to: 17;
		--scale-to-debug: '17';
	}
}

@media (resolution: 4.00dppx) {
	:root {
		--zoom-debug: '260% or 270%';
/*
for some mysterious reason both zoom levels matches this resolution
*/
		--dppx: 4.00;
		--dppx-debug: '4.00';
		--scale-to: 18;
		--scale-to-debug: '18';
	}
}

@media (resolution: 4.285714285714286dppx) {
	:root {
		--zoom-debug: '280% or 290%';
/*
for some mysterious reason both zoom levels matches this resolution
*/
		--dppx: 4.285714285714286;
		--dppx-debug: '4.285714285714286';
		--scale-to: 19;
		--scale-to-debug: '19';
	}
}

@media (resolution: 4.615384615384615dppx) {
	:root {
		--zoom-debug: '300%';
		--dppx: 4.615384615384615;
		--dppx-debug: '4.615384615384615';
		--scale-to: 20;
		--scale-to-debug: '20';
	}
}
}