One of them was Thomas Boutell, who on 4 January 1995 posted a precursory discussion thread on the Usenet newsgroup "aphics" in which he devised a plan for a free alternative to GIF. The patent required that all software supporting GIF pay royalties, leading to a flurry of criticism from Usenet users. The motivation for creating the PNG format was the realization that, on 28 December 1994, the Lempel–Ziv–Welch (LZW) data compression algorithm used in the Graphics Interchange Format (GIF) format was patented by Unisys. See also: Graphics Interchange Format § Unisys and LZW patent enforcement PNG was published as an informational RFC 2083 in March 1997 and as an ISO/IEC 15948 standard in 2004. PNG files have the ".png" file extension and the "image/png" MIME media type. A PNG file contains a single image in an extensible structure of chunks, encoding the basic pixels and other information such as textual comments and integrity checks documented in RFC 2083. The PNG working group designed the format for transferring images on the Internet, not for professional-quality print graphics therefore, non-RGB color spaces such as CMYK are not supported. PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without an alpha channel for transparency), and full-color non-palette-based RGB or RGBA images. ![]() PNG was developed as an improved, non-patented replacement for Graphics Interchange Format (GIF)-unofficially, the initials PNG stood for the recursive acronym "PNG's not GIF". Portable Network Graphics ( PNG, officially pronounced / p ɪ ŋ/ PING, colloquially pronounced / ˌ p iː ɛ n ˈ dʒ iː/ PEE-en- JEE) is a raster-graphics file format that supports lossless data compression. The great thing is that Photoshop already has all those separate layers, if you created your image like a professional.89 50 4e 47 0d 0a 1a 0a (8 bytes Hexadecimal) This sort of work was industry standard in Games for decades, and still is. Without color or lines, this should compress very well in PNG or JPEG.Ĭombine the layers into a single image with JavaScript, and your whole "image" could be 15KB or less. Again, all you need is a single 4 bit channel (alpha or grey). You only need a 1 pixel tall image, which you can stretch. You could compress this down to a single 4 bit channel (alpha or grey). The vertical lines with no color or noise.You could probably do it in less than 200 bytes of JS. Even better, use JavaScript to generate the color gradient on the client. This will compress well in PNG and very well in JPEG. The color gradient with no lines or noise.The image from the question looks like a color gradient with vertical lines and some splotches/noise. If you really need to shrink an image, and all the easy suggestions don't work, the final answer is to break the image into compressible pieces and recombine them on the client with scripting. Pngcrush some_8_bit.png -bit_depth 8 -brute -rem alla -reduce some_8_bit_small.png Pngout -c3 -d8 -y -force some_24_bit.png some_8_bit.png Here are the instructions how to convert png24 images into png8 for ie6 goodness, all through the command line using open source tools (i think) pngquant +pngout + pngcrush.ġ- quantize image into 256 (so basically png8′s look crap with large sprites or sprites with a large colour range). You will be able to control compression, number of colours, meta data settings and much more, and select image format (JPEG, GIF or PNG) for your output file.Īnother possibility is to use a combination of pngquant, pngout, and pngcrush, as described here, but this is from the command line. The image optimizer is lightweight, fast and simple to use, yet powerful for advanced users. ![]() It uses with a side by side (dual view) or single view interface to compare the original with the optimized image in real time and instantly see the resulting file size. Radical Image Optimization Tool (RIOT for short) is a free image optimizer that will let you to visually adjust compression parameters while keeping minimum file size.
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