1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
From 8effeb9120ac7e9214973c60d44b98d775749b39 Mon Sep 17 00:00:00 2001
From: Lovell Fuller <lovell@users.noreply.github.com>
Date: Tue, 11 Mar 2025 20:52:59 +0000
Subject: [PATCH] heifsave: improve alpha channel detection (#4394)
---
ChangeLog | 1 +
libvips/foreign/heifsave.c | 19 +++++--------------
2 files changed, 6 insertions(+), 14 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index d46e377e0..8d81352d1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -27,6 +27,7 @@
- tiffload: add missing read loop [kleisauke]
- prevent possible use-after-free when debugging via `--vips-leak` flag [lovell]
- avoid possible overflow when multiplication result is cast up [lovell]
+- heifsave: improve alpha channel detection [lovell]
10/10/24 8.16.0
diff --git a/libvips/foreign/heifsave.c b/libvips/foreign/heifsave.c
index 7479943ef..27cd7fb9a 100644
--- a/libvips/foreign/heifsave.c
+++ b/libvips/foreign/heifsave.c
@@ -289,8 +289,7 @@ vips_foreign_save_heif_write_page(VipsFo
#endif /*HAVE_HEIF_COLOR_PROFILE*/
options = heif_encoding_options_alloc();
- if (vips_image_hasalpha(save->ready))
- options->save_alpha_channel = 1;
+ options->save_alpha_channel = save->ready->Bands > 3;
#ifdef HAVE_HEIF_ENCODING_OPTIONS_OUTPUT_NCLX_PROFILE
/* Matrix coefficients have to be identity (CICP x/y/0) in lossless
@@ -522,6 +521,7 @@ vips_foreign_save_heif_build(VipsObject
char *chroma;
const struct heif_encoder_descriptor *out_encoder;
const struct heif_encoder_parameter *const *param;
+ gboolean has_alpha;
if (VIPS_OBJECT_CLASS(vips_foreign_save_heif_parent_class)->
build(object))
@@ -683,21 +683,13 @@ vips_foreign_save_heif_build(VipsObject *object)
heif->page_width = save->ready->Xsize;
heif->page_height = vips_image_get_page_height(save->ready);
heif->n_pages = save->ready->Ysize / heif->page_height;
+ has_alpha = save->ready->Bands > 3;
if (heif->page_width > 16384 || heif->page_height > 16384) {
vips_error("heifsave", _("image too large"));
return -1;
}
- /* Reject multiband images.
- */
- if (save->ready->Type == VIPS_INTERPRETATION_MULTIBAND) {
- vips_error("heifsave", _("Unsupported interpretation: %s"),
- vips_enum_nick(VIPS_TYPE_INTERPRETATION,
- save->ready->Type));
- return -1;
- }
-
/* Make a heif image the size of a page. We send sink_disc() output
* here and write a frame each time it fills.
*/
@@ -705,12 +697,11 @@ vips_foreign_save_heif_build(VipsObject *object)
printf("vips_foreign_save_heif_build:\n");
printf("\twidth = %d\n", heif->page_width);
printf("\theight = %d\n", heif->page_height);
- printf("\talpha = %d\n", vips_image_hasalpha(save->ready));
+ printf("\talpha = %d\n", has_alpha);
#endif /*DEBUG*/
error = heif_image_create(heif->page_width, heif->page_height,
heif_colorspace_RGB,
- vips__heif_chroma(heif->bitdepth,
- vips_image_hasalpha(save->ready)),
+ vips__heif_chroma(heif->bitdepth, has_alpha),
&heif->img);
if (error.code) {
vips__heif_error(&error);
|
