Module zune_imageprocs::crop

Crop an image

Algorithm

We can take cropping as a view into a sub-image which means

   width ──────────────────────────────►
│ ┌─────────────────────────────────────┐
│ │                                     │
│ │                                     │
│ │   (x,y)     out width               │
│ │     ┌────────────────────┐          │
│ │   o │                    │          │
│ │   u │                    │          │
│ │   t │                    │          │
│ │     │  CROPPED IMAGE     │          │
│ │   h │                    │          │
│ │   e │                    │          │
│ │   i │                    │          │
│ │   g │                    │          │
│ │   h └────────────────────┘          │
│ │   t                                 │
│ │                                     │
▼ │                                     │
  └─────────────────────────────────────┘

So a crop is essentially a weird memory copy starting from (x,y) like a small sub copy !!! That’s what we essentialy implement here

Specific implementation

So because we need to skip from 0–y we can use iter.skip(y) to point at y.

Since every iterator is moving a single line per height, we only iterate per out_height number of times, so we can achieve this with a take iterators. Rust iterators are fun!!

Structs

• Crop
  Crop out a part of an image

Functions

• crop
  Crop an image channel