An image in a DeviceN color space opened as an RGB image, losing its inks.
One of one colorant now opens as a Separation image does since #6347: a
grayscale image of its tints colorized by its ink. One of two to 32
colorants that are all process plates (the ink None may be among them)
opens as a CMYK image, each colorant's tint in its plate, its Decode array
applied (8 or 16 bits a sample). A DeviceN image that mixes a spot ink
with other colorants, such as a duotone, still opens as RGB.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
An image in a Separation color space opened as an RGB image: its spot ink
was lost (no plate in Separations Preview), and Fill and Recolor Artwork
didn't reach its color.
It now opens as a grayscale image of its tints (white where it lays no
ink, black at 100 %, its Decode array applied; 1 to 16 bits a sample, or
one gray channel from its JPEG, CCITT, JBIG2 or JPEG 2000 decoder),
colorized by its ink at 100 %: the spot swatch, a process plate's CMYK
color, or Registration. Its mask becomes its opacity mask, as a CMYK
image's does. The ink is found by the image's color space among those the
file defines, once per image. The ink None, an ink whose color can't be
told, images inside an alpha soft mask, inline images and DeviceN images
open as before; samples that can't be read open in RGB with a warning, and
the ink gets no swatch.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A CMYK image with an /SMask, /Mask or colour key was handed to the
interpreter and stored as an RGB PNG, converted with hayro's own bundled
profile (Perceptual) rather than the working CMYK, so it showed 10-30 levels
lighter than other CMYK images and lost its ink amounts. It now keeps its
inks as other CMYK images do (#320), and its alpha becomes a greyscale
opacity mask. PDF export already writes that as a DeviceCMYK image under a
soft mask, so a round trip keeps the inks.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A PDF's DeviceCMYK image opened as RGB (the interpreter's pixels as a PNG),
so every export wrote it as DeviceRGB or ICC RGB, silently. Images now keep
their CMYK samples, as CMYK colours already did:
- Model: CMYK images are blobs holding CMYK samples, a four-component JPEG
(Adobe's inverted samples) or a Deflate CMYK TIFF. vectorcraft-doc's cmyk
module reads their ink amounts (ImageBlob::is_cmyk, ::cmyk, capped at 64
megapixels) and writes the TIFF (ImageBlob::cmyk_tiff).
- PDF import: DeviceCMYK, CalCMYK and four-component ICC images keep their
samples. A JPEG with Decode [1 0 1 0 1 0 1 0] is kept byte for byte; any
other is decoded (8 or 16 bits, its Decode array applied) and stored as a
CMYK TIFF. Masked CMYK images and 1/2/4-bit ones open in RGB with a warning.
Placing a CMYK TIFF keeps it CMYK too.
- PDF export: CMYK images are written in CMYK (DeviceCMYK, or ICC-based with
the CMYK profile when colours are tagged: PDF/X-3, PDF/X-4, PDF/A). A CMYK
JPEG neither resampled nor recompressed passes through unchanged; others are
resampled in CMYK and compressed as ZIP or as a CMYK JPEG (jpeg-encoder,
which also replaces the ZIP fallback and its warning for images converted to
CMYK). Output conversion treats them like CMYK colours: Preserve Numbers and
PDF/X-1a keep their numbers, Convert to Destination converts them to another
CMYK profile or to RGB through a 17^4 lookup table (cms::CmykLut, now also
behind the renderer's ink table). A CMYK image that can't be decoded is
reported in the warnings.
- Canvas: CMYK images show through the working CMYK profile, as CMYK fills
do, and paint their own inks in ink planes (CMYK raster exports, CMYK
blending). SVG export writes TIFF images as PNG.
Illustrator's Output › No Conversion keeps colour data as it is
(https://helpx.adobe.com/illustrator/using/pdf-options.html).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
