Preparation of a large number of images in a loop about fast_image_resize HOT 6 CLOSED

You can reuse the memory buffer that is used for dst_image.

let mut dst_buffer: Vec<u8> = Vec:new();
for variation in variations {
    ...
    let dst_buf_size = ...;
    dst_buffer.resize(dst_buf_size, 0);
    let mut dst_image = fr::Image::from_slice_u8(
       dst_width,
       dst_height,
       &mut dst_buffer,
       src_image.pixel_type(),
   ).unwrap();
   ...
}

I think that creating an instance of JpegEncoder is a fairly easy operation. But you may look at the image crate documentation. May be you can find something about how to reuse exists JpegEncoder instance to encode different images.

But, in any case, to store 100+ result images you must create 100+ vectors.

from fast_image_resize.

Move these lines inside of for-loop:

    let mut result_buffer: Vec<u8> = Vec::new();
    let mut buf_writer = BufWriter::new( &mut result_buffer );
    let mut encoder = JpegEncoder::new_with_quality( &mut buf_writer, 100 );

from fast_image_resize.

Is there a way to avoid creating new instances in the loop?

from fast_image_resize.

Your question is irrelevant to the fast_image_resize crate. It is more related to the Rust language and how computer's memory works. Value of the result_buffer variable can't be used after it is moved into image_variations vector.
How do you want to use the same buffer to store different images at the same time? It is impossible. You must create a new buffer to store each image.

from fast_image_resize.

Thank you, let me modify my question, if the encoder and the resizer holds the logic of how to process images: Is there a way to create only one instance of these two, to use in +100 resize & encode ops. in loop?

from fast_image_resize.

Thank you!

from fast_image_resize.