Using GhostScript by shelling out to a command line will not require you to change your licensing in any way. Batch files used to call GhostScript aren't automagically GPL'ed.
With GPL, I'd always understood that it boiled down to "Separate process? Separate license!".
So you just have GS whip up a relatively hi DPI version of the PDF page in question, and let the user pan and zoom around in that. Because GS IS in a separate process, you could fire off additional page requests in the background so the user won't perceive a delay when paging back and forth. GS takes a page range as one of its conversion parameters.
What you couldn't do is generate an image of a small part of an individual PDF page at high DPI/zoom. IIRC, you have to render the whole page.
如果您的应用程序是开源且免费的，那么您应该考虑选择托管 Adobe Reader ActiveX 控件（需要安装 Adobe Reader），此行为与 Internet Explorer 或 Firefox 浏览器中嵌入的 Adobe Reader 相同。
许多用户的计算机上已经安装了 Adobe Reader 或 Foxit Reader。
If your application is open source and free then you should consider the option to host Adobe Reader ActiveX control (which requires to have Adobe Reader to be installed), this behavior would be the same as embedded Adobe Reader in Internet Explorer or Firefox browsers.
Lot of users have Adobe Reader or Foxit Reader installed on their computers already.
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似乎有一个新的 BSD 许可竞争者：PDFium。
It seems that there is a new BSD-licensed contender: PDFium.
IANAL。巴拉巴拉巴拉。
通过 shell 到命令行来使用 GhostScript 不需要您以任何方式更改您的许可。用于调用 GhostScript 的批处理文件不会自动进行 GPL 许可。
对于 GPL，我一直认为它归结为“单独的进程？单独的许可证！”。
因此，您只需让 GS 生成相关 PDF 页面的 DPI 相对较高的版本，然后让用户平移和缩放即可。由于 GS 处于单独的进程中，因此您可以在后台触发其他页面请求，以便用户在来回分页时不会感觉到延迟。 GS 将页面范围作为其转换参数之一。
您无法以高 DPI/缩放生成单个 PDF 页面的一小部分图像。 IIRC，你必须渲染整个页面。
IANAL. Blah blah blah.
Using GhostScript by shelling out to a command line will not require you to change your licensing in any way. Batch files used to call GhostScript aren't automagically GPL'ed.
With GPL, I'd always understood that it boiled down to "Separate process? Separate license!".
So you just have GS whip up a relatively hi DPI version of the PDF page in question, and let the user pan and zoom around in that. Because GS IS in a separate process, you could fire off additional page requests in the background so the user won't perceive a delay when paging back and forth. GS takes a page range as one of its conversion parameters.
What you couldn't do is generate an image of a small part of an individual PDF page at high DPI/zoom. IIRC, you have to render the whole page.
如果您的应用程序是开源且免费的，那么您应该考虑选择托管 Adobe Reader ActiveX 控件（需要安装 Adobe Reader），此行为与 Internet Explorer 或 Firefox 浏览器中嵌入的 Adobe Reader 相同。
许多用户的计算机上已经安装了 Adobe Reader 或 Foxit Reader。
If your application is open source and free then you should consider the option to host Adobe Reader ActiveX control (which requires to have Adobe Reader to be installed), this behavior would be the same as embedded Adobe Reader in Internet Explorer or Firefox browsers.
Lot of users have Adobe Reader or Foxit Reader installed on their computers already.