问题描述
我知道如何使用后记
我现在正在寻找如何绘制内容(width * height)到postscript页面(x,y,width,height)没有任何外部库(FOP,PDFBox ...)。
I'm now looking how to draw the content BufferedImage(width*height) to a postscript page (x,y,width,height) without any external library (FOP,PDFBox...).
你有任何提示/代码/算法吗?
Do you have any hint/code/algorithm ?
谢谢! : - )
推荐答案
必须使用图像
或 colorimage
运算符。
与简单的有线和 show
文本运算符不同,这些是带有几个参数的复杂运算符
。
One has to use the image
or colorimage
operators.Unlike the simple linedrawing and show
text operator, these are complex operatorsthat take several parameters.
我正在使用示例postscript片段,使用
7参数 colorimage
运算符渲染8 x 8图像。请注意,第5个参数实际上是一个回调过程,可以由colorimage运算符多次调用,每次都返回字符串中的一些图像数据。在此示例中,我立即返回整个图像数据。
在此示例中,此数据是ASCII编码的,每个字节表示为2位十六进制数。更高效的编码是可能的,因为Postscript可以在运行时解码base64,base85和RLE编码。
I am putting a sample postscript snippet which renders an 8 x 8 image using the7 parameter colorimage
operator. Take notice that the 5th parameter is actually a callback procedure, that may be called several times by the colorimage operator, each time returning some of the image data in a string. In this example, I return the whole image data at once.In this example, this data is ASCII encoded with each byte being represented as 2-digit hexadecimal number. More efficient encodings are possible, as Postscript can decode base64, base85 and RLE encoding in runtime.
此参数可能是单个字符串而不是回调过程,但在此case,
二进制数据必须以八进制转义,前面的斜杠(如\ 377)表示十进制255.使用用 currentfile $ c $读取的内联数据c>运算符通常是
来表示Postscript图像。
This parameter might be a single string instead of a callback procedure, but in this case,binary data would have to be escaped in octal, with a preceding slash (like \377) for decimal 255. Using inline data that is read with the currentfile
operator is rather usualfor representing Postscript images.
请注意,图像通常映射到渲染空间上的(0,0,1,1)方格,而
必须设置全局转换矩阵( translate
, scale
, rotate
运算符在渲染图像之前。
Note that the image is usually mapped to the (0,0,1,1) square on the renderign space, andone has to set the global transformation matrix (with the translate
, scale
, rotate
operators) prior to rendering the image.
完整的图像
和 colorimage
参考可以在Adobe的Postscript语言参考上找到,可以在
The complete image
and colorimage
reference can be found on the Postscript Language Refrence by Adobe available at http://www.adobe.com/products/postscript/pdfs/PLRM.pdf
再举一个例子,试试运行 GIMP
编程并将图像保存为Postscript。
For another example, try running the GIMP
program and saving an image as Postscript from within it.
%!PS-Adobe-3.0
% builds string to hold all image data at once:
/imgdata 8 8 3 mul mul string def
% set context to scale image to 256 X 256 pt (from 1 x1 pt)
256 256 scale
% Dimensions of image (width * height * bpp)
8 8 8
% Image transformation Matrix - [width 0 0 -height 0 height]: flips
% vertical axis so we have top to bottom data:
[8 0 0 -8 0 8]
% Procedure to read the image data and return it as a string:
{ currentfile % read inline data
imgdata % put read data into this variable
readhexstring % performs the reading
pop % discards read operation status
}
%indicates single data source:
false
%number of colors per pixel:
3
% Image operator: consumes previous parameters and renders the image
% followed by Image hexadecimal data in ASCII
colorimage
0000000000200000400000600000800000a00000c00000e0200000200020
2000402000602000802000a02000c02000e0400000400020400040400060
4000804000a04000c04000e06000006000206000406000606000806000a0
6000c06000e08000008000208000408000608000808000a08000c08000e0
a00000a00020a00040a00060a00080a000a0a000c0a000e0c00000c00020
c00040c00060c00080c000a0c000c0c000e0e00000e00020e00040e00060
e00080e000a0e000c0e000e0
showpage
这篇关于将BufferedImage转换/写入postscript的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!