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Questions tagged [png-8]

PNG8 (or png-8) is a subset of possible png files. PNG8 files are indexed PNG files with either no transparency or only binary (GIF-style) transparency in which all pixels are either fully opaque or fully transparent.

PNG8 (or png-8) is a subset of possible png files. PNG8 files are indexed PNG files with either no transparency or only binary (GIF-style) transparency in which all pixels are either fully opaque or fully transparent.

define PNG8 as 8-bit indexed PNG with optional binary transparency.

Some people use "png-8" to mean 8-bit indexed files with all 256 levels of transparency allowed, but those could simply be called "indexed" PNGs. The libpng FAQ, (http://www.libpng.org/pub/png/pngfaq.html#png8-png24) doesn't mention transparency in its discussion of PNG8.

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What is difference between png8 and png24

I want to know about uses of png files. There are two formats available for png images; one is png8 and the another one is png24. I would like to know that if I use either type in my html page, will there be any error? Or is this only quality…
Kesar Sisodiya
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Convert 32 bit png to 8 bit png with ImageMagick by preserving semi transparent pixels

I want to convert 32 bit png to 8 bit png with ImageMagick, but semi transparent pixels are lost. How to solve this problem? The command that I am using is the following convert original.png PNG8:output.png
Karmar
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PHP gdLib 8-Bit PNG with alpha

how is it possible to save my image, created with gd, as an png-8? it saves as gif with transparent channel well - but I want to use png-8. Best Regards, Beerweasle
Beerweasle
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How to convert PNG to 8-bit PNG using PHP GD library

I want to write a routine which takes PNG image path as parameter and convert that image into 8-bit PNG image. I need to use PHP GD library for this.
Nilesh
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How can you tell png8 from a png24

I'm working on a website that uses lots of png24 files, for transparency. I need to replace them with png8 files, as all the png fix style javascript workarounds for png24 cause IE6 to lock up randomly. See this link to get an idea of the symptoms…
Chris Adams
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How to save 8-bit PNGs with ChunkyPNG or RMagick

I've been trying to save 8-bit PNGs (PNG8) using RMagick (http://rmagick.rubyforge.org/) and ChunkyPNG (https://github.com/wvanbergen/chunky_png) but have been unable to do so. However the only time I can get it to work on RMagick is if the…
anami
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Reduce Color Count in PNG-8 Palette using FreeImage Library (C#)

I was using the FreeImageNET libary to Quantize my Bitmap as using (FreeImageAPI.FreeImageBitmap fiBitmap = FreeImageAPI.FreeImageBitmap.FromHbitmap(bmp.GetHbitmap())) { if (fiBitmap.ColorDepth > 24) { …
nbaztec
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Is there some library in Java to compress Png images like pngout?

Is there some library in Java to compress Png images like pngout, pngcrush, optipng which are written in C/C++? In continuation to what Phil has commented below, what I meant was reducing the file size of the image generated by the ImageIO class in…
Prabhu R
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How to tell if image is PNG24 or PNG8 and the number of bits and channels?

I am trying to distinguish PNG-8 and PNG-24 images with getimagesize or Imagick, but I don't quite know how to to it. getimagesize does not return channels for my PNGs and displays the mimetype instead. It works well for other images and shows the…
shapeshifta
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How can you tell whether the file you've downloaded in PNG-8, PNG-24, or PNG-32?

I'm trying to download a picture off the net, and I'm saving it as a png file (image.png). How can I tell whether the image is a PNG-8, PNG-24 or PNG-32 file (is there a default?) and is there anyway of changing the file type to one or the other?…
the12
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Create Paletted CGImageRef

I'm trying to create a paletted (indexed) PNG using CoreGraphics. The best I've found is that I can use: CGColorSpaceRef colorSpace = CGColorSpaceCreateIndexed(CGImageGetColorSpace(maskedImage), 255, <#const unsigned char…
Chris Nolet
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How to remove the alpha channel of a png-24 image by java？

I have a png-24 images,how can I do to remove its alpha channel?Or how to convert it to png-8 format? Here is my codes,but it can't be worked. BufferedImage src = ImageIO.read(source); AffineTransform xform=AffineTransform.getScaleInstance(1.0,…
Reevs Li
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PNG8+Alpha from Fireworks (colormap) are different/smaller than from elsewhere (RGBA). Why?

In Fireworks, when you export a PNG8 file with alpha transparency, the resulting file will be something like this: png8-fireworks.png: PNG image data, 500 x 500, 8-bit colormap, non-interlaced If you convert a 32bit PNG using other tools (PNGOUT,…
timkelty
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Save PNG as PNG-8 with Floyd-Steinberg 2 dithering like GIMP in PHP

In GIMP I can save an image for Web with these properties: PNG-8 256 colors palette Dither: Floyd-Steinberg / Floyd-Steinberg 2 / positioned With these options I can reduce upto about 70% of the size of the image file without evident quality…
user2342558
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Imagemagick lower PNG depth

I have a huge number of images provided from various artists working on a project. The images have varying specs, but all are PNGs. Some are 8-bit indexed (palette), others are true color with alpha 32-bit and 64-bit PNGs. Now, I am trying to use…
Mazyod
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