Mathis/sharp
1
0
Fork 0
mirror of https://github.com/lovell/sharp.git synced 2025-12-19 07:15:08 +01:00
Code Issues Packages Projects Releases Wiki Activity

Add ability to extend (pad) the edges of an image

Browse Source
This commit is contained in:
Lovell Fuller
2016-03-03 09:18:11 +00:00
parent 86815bc9c4
commit f950294f70
8 changed files with 139 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
src/pipeline.cc
View File

@@ -522,6 +522,27 @@ class PipelineWorker : public AsyncWorker {
);
}
// Extend edges
if (baton->extendTop > 0 || baton->extendBottom > 0 || baton->extendLeft > 0 || baton->extendRight > 0) {
// Scale up 8-bit values to match 16-bit input image
const double multiplier = (image.interpretation() == VIPS_INTERPRETATION_RGB16) ? 256.0 : 1.0;
// Create background colour
std::vector<double> background {
baton->background[0] * multiplier,
baton->background[1] * multiplier,
baton->background[2] * multiplier
};
// Add alpha channel to background colour
if (HasAlpha(image)) {
background.push_back(baton->background[3] * multiplier);
}
// Embed
baton->width = image.width() + baton->extendLeft + baton->extendRight;
baton->height = image.height() + baton->extendTop + baton->extendBottom;
image = image.embed(baton->extendLeft, baton->extendTop, baton->width, baton->height,
VImage::option()->set("extend", VIPS_EXTEND_BACKGROUND)->set("background", background));
}
// Threshold - must happen before blurring, due to the utility of blurring after thresholding
if (shouldThreshold) {
image = image.colourspace(VIPS_INTERPRETATION_B_W) >= baton->threshold;
@@ -991,6 +1012,10 @@ NAN_METHOD(pipeline) {
baton->rotateBeforePreExtract = attrAs<bool>(options, "rotateBeforePreExtract");
baton->flip = attrAs<bool>(options, "flip");
baton->flop = attrAs<bool>(options, "flop");
baton->extendTop = attrAs<int32_t>(options, "extendTop");
baton->extendBottom = attrAs<int32_t>(options, "extendBottom");
baton->extendLeft = attrAs<int32_t>(options, "extendLeft");
baton->extendRight = attrAs<int32_t>(options, "extendRight");
// Output options
baton->progressive = attrAs<bool>(options, "progressive");
baton->quality = attrAs<int32_t>(options, "quality");

8
src/pipeline.h
View File

@@ -60,6 +60,10 @@ struct PipelineBaton {
bool rotateBeforePreExtract;
bool flip;
bool flop;
int extendTop;
int extendBottom;
int extendLeft;
int extendRight;
bool progressive;
bool withoutEnlargement;
VipsAccess accessMethod;
@@ -106,6 +110,10 @@ struct PipelineBaton {
angle(0),
flip(false),
flop(false),
extendTop(0),
extendBottom(0),
extendLeft(0),
extendRight(0),
progressive(false),
withoutEnlargement(false),
quality(80),