You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
73 lines
2.2 KiB
73 lines
2.2 KiB
// Copyright 2016 Drew Short <drew@sothr.com>.
|
|
//
|
|
// Licensed under the MIT license<LICENSE-MIT or http://opensource.org/licenses/MIT>.
|
|
// This file may not be copied, modified, or distributed except according to those terms.
|
|
extern crate image;
|
|
|
|
use std::path::Path;
|
|
|
|
use cache::Cache;
|
|
|
|
use super::{HashType, PerceptualHash, Precision, PreparedImage};
|
|
use super::prepare_image;
|
|
|
|
use self::image::{GenericImage, GenericImageView};
|
|
|
|
pub struct DHash<'a> {
|
|
prepared_image: Box<PreparedImage<'a>>,
|
|
}
|
|
|
|
impl<'a> DHash<'a> {
|
|
pub fn new(path: &'a Path, precision: &Precision, cache: &Option<Cache>) -> Self {
|
|
DHash {
|
|
prepared_image: Box::new(prepare_image(&path, &HashType::DHash, &precision, cache)),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<'a> PerceptualHash for DHash<'a> {
|
|
/**
|
|
* Calculate the dhash of the provided prepared image
|
|
*
|
|
* # Return
|
|
*
|
|
* Returns a u64 representing the value of the hash
|
|
*/
|
|
fn get_hash(&self, _: &Option<Cache>) -> u64 {
|
|
match self.prepared_image.image {
|
|
Some(ref image) => {
|
|
let (_, _, first_pixel) = image.pixels().nth(0).unwrap();
|
|
let (_, _, last_pixel) = image.pixels().last().unwrap();
|
|
let first_pixel_value = first_pixel.0[0] as u64;
|
|
let last_pixel_value = last_pixel.0[0] as u64;
|
|
|
|
// Calculate the dhash
|
|
let mut previous_pixel_value = 0u64;
|
|
let mut hash = 0u64;
|
|
for (x, y, pixel) in image.pixels() {
|
|
if x == 0 && y == 0 {
|
|
previous_pixel_value = pixel.0[0] as u64;
|
|
continue;
|
|
}
|
|
let pixel_val = pixel.0[0] as u64;
|
|
if pixel_val >= previous_pixel_value {
|
|
hash |= 1;
|
|
} else {
|
|
hash |= 0;
|
|
}
|
|
hash <<= 1;
|
|
previous_pixel_value = first_pixel_value;
|
|
}
|
|
|
|
if first_pixel_value >= last_pixel_value {
|
|
hash |= 1;
|
|
} else {
|
|
hash |= 0;
|
|
}
|
|
|
|
hash
|
|
}
|
|
None => 0u64,
|
|
}
|
|
}
|
|
}
|