我想用 ConTeXt 生成有效的 PDF/X-1a 文件。我目前正在做
\setupbackend[
format=PDF/X-1a:2001,
intent={Coated FOGRA39 (ISO 12647-2:2004)}]
但是，当我在 Acrobat 中验证生成的 PDF 时，我收到很多错误。以下是前三个：
Object uses RGB
Is DeviceRGB
Outside visible page area
Detailed information
Graphic state properties
Graphic properties
Current transformation matrix (CTM)
1.000000
0.000000
0.000000
1.000000
0.000000
267.986786
X translation: 0.000000
Y translation: 267.986786
X scaling: 1.000000
Y scaling: 1.000000
Rotation counterclockwise: 0.000000
Skew: 0.000000
Effective line width: 0.398500
Miter limit: 10.000000
Stroke adjustment: False
Flatness: 1.000000
Smoothness: 0.000000
Overprint mode: 0
Overprint for stroke: False
Overprint for fill: False
Rendering intent: RelativeColorimetric
Line dash pattern
Dash phase: 0.000000
Line cap style: Butt end caps
Line join style: Miter joins
Fill color space
DeviceRGB color space
Fill colorant values
0.137000
0.122000
0.125000
Stroke color space
DeviceGray color space
Transparency
Fill constant alpha: 1.000000
Stroke constant alpha: 1.000000
Alpha is shape: False
Text knockout: True
Object uses RGB
Is DeviceRGB
Detailed information
Graphic state properties
Images
Current transformation matrix (CTM)
170.348892
0.000000
0.000000
257.952698
6.952600
8.505585
X translation: 0.040814
Y translation: 0.032973
X scaling: 170.348892
Y scaling: 257.952698
Rotation counterclockwise: 0.000000
Skew: 0.000000
Current position and size
X position on page (pt): 6.952600
Y position on page (pt): 8.505585
Width on page (pt): 170.348892
Height on page (pt): 257.952698
Current image resolution
Horizontal resolution (pixels/inch): 978.039795
Vertical resolution (pixels/inch): 978.039795
Width: 2314
Height: 3504
Bits per color component: 8
Treated as a mask: False
Perform interpolation: False
Rendering intent: RelativeColorimetric
Compression/encoding
ZIP/Flate compression: FlateDecode
DeviceRGB color space
Object uses RGB
Is DeviceRGB
Detailed information
Graphic state properties
Graphic properties
Current transformation matrix (CTM)
1.000000
0.000000
0.000000
1.000000
0.000000
0.000002
X translation: 0.000000
Y translation: 0.000002
X scaling: 1.000000
Y scaling: 1.000000
Rotation counterclockwise: 0.000000
Skew: 0.000000
Effective line width: 0.398500
Miter limit: 10.000000
Stroke adjustment: False
Flatness: 1.000000
Smoothness: 0.000000
Overprint mode: 0
Overprint for stroke: False
Overprint for fill: False
Rendering intent: RelativeColorimetric
Line dash pattern
Dash phase: 0.000000
Line cap style: Butt end caps
Line join style: Miter joins
Fill color space
DeviceRGB color space
Fill colorant values
0.000000
0.000000
0.000000
Stroke color space
DeviceGray color space
Text properties
Type 0 font
PostScript name: NewG8-Bol
Unicode CMap is present
Encoding: Identity-H
Font is a subset
Descendant fonts
CID Type 0 font
CID font system info
Issuer (Registry): "Adobe"
Unique name (Ordering): "Identity"
Supplement number (Supplement): 0
Embedded: True
Font descriptors
Maximum height above the baseline: 777
y-coordinate of the top of flat capital letters: 696
Maximum depth below the baseline: -223
Italic angle in degrees counterclockwise: 0
Width of the dominant vertical stems of glyphs: 92
Average width of characters: 0
Desired spacing between lines: 0
Maximum width of characters: 0
Width to use for un-encoded characters.: 0
Vertical width of the dominant horizontal stems of glyphs: 0
y-coordinate of the top of flat non-ascending lowercase letters: 439
PostScript name: TWTZWX+NewG8-Bol
Various properties
Fixed-width font: False
Serif font: False
Symbolic font: True
Script font: False
Uses the Adobe Standard Roman Character Set: False
Italic: False
All-caps font: False
Small-caps font: False
Force bold at small text sizes: False
Current font size: 8.368596
Transparency
Fill constant alpha: 1.000000
Stroke constant alpha: 1.000000
Alpha is shape: False
Text knockout: True
因此，据我了解，所包含的图像和文本都使用 RGB 颜色。这似乎很奇怪，因为我专门定义了目标颜色空间，难道不应该正确地对颜色进行编码吗？我还需要做什么吗？
答案1
除非 ConTeXt 具有将图像从 RGB 重新组合为 CMYK 的图形功能，否则您必须自己动手。使用 ImageMagick 或 GraphicsMagick 可以轻松完成此操作。此外，对于 PDF/X-1a:2001，图像必须去除元数据（例如 EXIF）并且不附加颜色配置文件。
用于执行此操作的脚本（BASH）和有用的颜色配置文件位于类文档的“extras”目录中novel。它们可以与任何文档类或 TeX 编译器一起使用，因为它们是 BASH（或 Windows）脚本。
但是既然您有 Acrobat DC，为什么不让该程序为您完成这项工作呢？不确定您是否需要“专业版”。它可以处理图像、添加或删除元数据等等。