image-rendering

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the spec changes.

Summary

The image-rendering CSS property provides a hint to the user agent about how to handle its image rendering.  It applies to any images appearing on the element properties, but has no effect on non-scaled images.. For example, if the natural size of the image is 100×100px but the page author specifies the dimensions to 200×200px (or 50×50px), then the image will be upscaled (or downscaled) to the new dimensions using the specified algorithm. Scaling may also apply due to user interaction (zooming).

Syntax

Formal syntax: auto | crisp-edges | pixelated
image-rendering: auto
image-rendering: crisp-edges
image-rendering: pixelated

image-rendering: inherit

Values

auto
Default value, the image should be scaled with an algorithm that maximizes the appearance of the image. In particular, scaling algorithms that "smooth" colors are acceptable, such as bilinear interpolation. This is intended for images such as photos. Since version 1.9 (Firefox 3.0), Gecko uses bilinear resampling (high quality).
crisp-edges
The image must be scaled with an algorithm that preserves contrast and edges in the image, and which does not smooth colors or introduce blur to the image in the process. This is intended for images such as pixel art.
pixelated
When scaling the image up, the "nearest neighbor" or similar algorithm must be used, so that the image appears to be simply composed of very large pixels. When scaling down, this is the same as 'auto'.
The values optimizeQuality and optimizeSpeed present in early draft (and coming from its SVG counterpart) are defined as synonyms for the auto value.

Examples

/* applies to GIF and PNG images; avoids blurry edges */

img[src$=".gif"], img[src$=".png"] {
                   image-rendering: -moz-crisp-edges;         /* Firefox */
                   image-rendering:   -o-crisp-edges;         /* Opera */
                   image-rendering: -webkit-optimize-contrast;/* Webkit (non-standard naming) */
                   image-rendering: crisp-edges;
                   -ms-interpolation-mode: nearest-neighbor;  /* IE (non-standard property) */
                 }

div { 
        background: url(chessboard.gif) no-repeat 50% 50%;
        image-rendering: -moz-crisp-edges;         /* Firefox */
        image-rendering:   -o-crisp-edges;         /* Opera */
        image-rendering: -webkit-optimize-contrast;/* Webkit (non-standard naming) */
        image-rendering: crisp-edges;
        -ms-interpolation-mode: nearest-neighbor;  /* IE (non-standard property) */
}

Live Examples

image-rendering:optimizeQuality; -ms-interpolation-mode:bicubic;
78%squares.gif 100%squares.gif 138%squares.gif downsizedhut.jpg upsizedblumen.jpg

image-rendering:-moz-crisp-edges; image-rendering: -o-crisp-edges; image-rendering:-webkit-optimize-contrast; -ms-interpolation-mode:nearest-neighbor;
78%squares.gif 100%squares.gif 138%squares.gif downsizedhut.jpg upsizedblumen.jpg

Specifications

Specification Status Comment
CSS Image Values and Replaced Content Module Level 4 Working Draft  

Though initially close from the SVG image-rendering property, the values are quite different now.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (auto) (Yes) 3.6 (1.9.2) Not supported [1] 11.60 6533.21.1, r86920
crisp-edges Not supported 3.6 (1.9.2)-moz Not supported 11.60-o 6533.21.1, r86920 with the non-standard name -webkit-optimize-contrast
pixelated Not supported [2] Not supported Not supported Not supported Not supported
optimizeQuality, optimizeSpeedNon-standard Not supported 3.6 (1.9.2) Not supported 11.60 6533.21.1, r86920
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support ? ? ? ? ?

Notes

[1] Internet Explorer 7 and 8 supports the non-standard -ms-interpolation-mode property with two values (bicubic and nearest-neighbor):

  • applies only to images (JPG, GIF, PNG, ...)
  • in IE7 only for images without transparency
  • does not inherit
  • default value IE7: nearest-neighbor (low quality)
  • default value IE8: bicubic (high quality)
  • obsolete as of IE9

[2] Chrome bug tracking the implementation; includes work around: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/Q8N6FoeoPXI

 

Canvas can provide a fallback solution for crisp-edge/optimize-contrast through manual imageData manipulation.

Attachments

File Size Date Attached by
blumen.jpg
2288 bytes 2009-06-05 14:19:00 Jürgen Jeka
squares.gif
232 bytes 2009-06-05 14:19:01 Jürgen Jeka
hut.jpg
18558 bytes 2009-06-05 14:20:11 Jürgen Jeka
moveDialog.png
19863 bytes 2012-02-02 15:33:20 Potappo
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