📄 faq-doc-21.html
字号:
<HEAD>
<TITLE>JPEG image compression FAQ, part 1/2 - [21] What if I need more than 8-bit precision?</TITLE>
</HEAD>
<BODY>
Parent document is top of "<A NAME=up HREF="faq.html" tppabs="http://www.cis.ohio-state.edu/hypertext/faq/usenet/jpeg-faq/part1/faq.html"><I>JPEG image compression FAQ, part 1/2</I></A>"<BR>
Previous document is "<A NAME=up HREF="faq-doc-20.html" tppabs="http://www.cis.ohio-state.edu/hypertext/faq/usenet/jpeg-faq/part1/faq-doc-20.html"><I>[20] Isn't there an M-JPEG standard for motion pictures?</I></A>"<BR>
Next document is "<A NAME=up HREF="faq-doc-22.html" tppabs="http://www.cis.ohio-state.edu/hypertext/faq/usenet/jpeg-faq/part1/faq-doc-22.html"><I>[22] How can my program extract image dimensions from a JPEG file?</I></A>"<BR>
<HR>
<H1>[21] What if I need more than 8-bit precision?</H1>
<PRE>
Baseline JPEG stores images with 8 bits per color sample, in other words
24 bits per pixel for RGB images, 8 bits/pixel for grayscale, 32 bits/pixel
for CMYK, etc. There is an extension that stores 12 bits/sample for
applications that need higher accuracy. Medical images, for example, are
often 12-bit grayscale. The 12-bit extension is not very widely supported,
however. One package that does support it is the free IJG source code (see
part 2, item 15).
For lossless JPEG, the standard permits any data precision between 2 and 16
bits per sample, but high-precision lossless JPEG is even less widely
supported than high-precision lossy JPEG. The Stanford PVRG codec (see
part 2, item 15) reportedly supports up to 16 bits/sample for lossless JPEG.
</PRE>
<HR>
Parent document is top of "<A NAME=up HREF="faq.html" tppabs="http://www.cis.ohio-state.edu/hypertext/faq/usenet/jpeg-faq/part1/faq.html"><I>JPEG image compression FAQ, part 1/2</I></A>"<BR>
Previous document is "<A NAME=up HREF="faq-doc-20.html" tppabs="http://www.cis.ohio-state.edu/hypertext/faq/usenet/jpeg-faq/part1/faq-doc-20.html"><I>[20] Isn't there an M-JPEG standard for motion pictures?</I></A>"<BR>
Next document is "<A NAME=up HREF="faq-doc-22.html" tppabs="http://www.cis.ohio-state.edu/hypertext/faq/usenet/jpeg-faq/part1/faq-doc-22.html"><I>[22] How can my program extract image dimensions from a JPEG file?</I></A>"<BR>
</BODY>
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -