How to use imageio - 10 common examples

Obj_Detector = obj.Object_Detector(obj_detection_graph)
    Tracker = obj.Tracker()

    test_vid_path = "chase1Person1View3Point0.mp4"
    print('Testing on %s' % test_vid_path)

    reader = imageio.get_reader(test_vid_path, 'ffmpeg')
    fps = reader.get_meta_data()['fps'] // 2

    # out_vid_path = "chase1Person1View3Point0_out.mp4"
    # writer = imageio.get_writer(out_vid_path, fps=fps)
    # print("Writing output video on %s" %out_vid_path)
    actors = [0,1,2]
    writers = []
    for ii in actors:
        writer = imageio.get_writer("person_%i.mp4" % ii, fps=fps)
        print("Video writer set for person_%i" % ii)
        writers.append(writer)

    frame_cnt = 0
    for test_img in reader:
        frame_cnt += 1
        if frame_cnt % 2 == 0:
            continue
        print("frame_cnt: %i" %frame_cnt)
        expanded_img = np.expand_dims(test_img, axis=0)
        detection_list = Obj_Detector.detect_objects_in_np(expanded_img)
        detection_info = [info[0] for info in detection_list]
        Tracker.update_tracker(detection_info, test_img)
        if frame_cnt > 30:
            print("writing segments")
            for actor_no, writer in zip(actors,writers):

#Written by Timothy Seabrook
#timothy.seabrook@cs.ox.ac.uk

import imageio
import glob

filenames = glob.glob('/Users/seabrook/Documents/FDL/Kernel/' + '*.png')

with imageio.get_writer('/Users/seabrook/Documents/FDL/Kernel/kernel.gif', mode='I', duration=0.04) as writer:
    for i in range(len(filenames) // 4):
        image = imageio.imread(filenames[i])
        writer.append_data(image)

tile_sz=size,
                                                  wsize=wsize)
            pred = (out_img * 255).cpu().numpy().astype(np.uint8)
            preds.append(pred)
            #imsave(folder/f'{t}.tif', pred[0])

            orig = (img[wsize // 2][None] * 255).astype(np.uint8)
            origs.append(orig)
        if len(preds) > 0:
            all_y = img_to_uint8(np.concatenate(preds))
            imageio.mimwrite(
                pred_out, all_y,
                bigtiff=True)  #, fps=30, macro_block_size=None) # for mp4

            all_y = img_to_uint8(np.concatenate(origs))
            imageio.mimwrite(orig_out, all_y,
                             bigtiff=True)  #, fps=30, macro_block_size=None)

def get_img(self, path, norm_size=True, norm_exposure=False):
        """
    Prepare an image for image processing tasks
    param path: the input image path
    type x: str
    return: the image
    rtype: numpy.ndarray
    """
        # flatten returns a 2d grayscale array
        img = imageio.imread(path, as_gray=True).astype(int)
        # resizing returns float vals 0:255; convert to ints for downstream tasks
        if norm_size:
            img = skimage.transform.resize(
                img, (self.height, self.width), mode="constant", preserve_range=True
            )
        if norm_exposure:
            img = self.normalize_exposure(img)
        return img

def test_png():

    for isfloat in (False, True):
        for crop in (0, 1, 2):
            for colors in (0, 1, 3, 4):
                fname = fnamebase + "%i.%i.%i.png" % (isfloat, crop, colors)
                rim = get_ref_im(colors, crop, isfloat)
                imageio.imsave(fname, rim)
                im = imageio.imread(fname)
                mul = 255 if isfloat else 1
                assert_close(rim * mul, im, 0.1)  # lossless

    # Parameters
    im = imageio.imread("imageio:chelsea.png", ignoregamma=True)
    imageio.imsave(fnamebase + ".png", im, interlaced=True)

    # Parameter fail
    raises(TypeError, imageio.imread, "imageio:chelsea.png", notavalidk=True)
    raises(TypeError, imageio.imsave, fnamebase + ".png", im, notavalidk=True)

    # Compression
    imageio.imsave(fnamebase + "1.png", im, compression=0)
    imageio.imsave(fnamebase + "2.png", im, compression=9)
    s1 = os.stat(fnamebase + "1.png").st_size
    s2 = os.stat(fnamebase + "2.png").st_size
    assert s2 < s1
    # Fail
    raises(ValueError, imageio.imsave, fnamebase + ".png", im, compression=12)

    # Quantize

def test_random_access():

    im1 = imageio.imread("imageio:chelsea.png")
    ims1 = [im1, im1 * 0.8, im1 * 0.5]

    fname = os.path.join(test_dir, "chelseam.bsdf")
    imageio.mimsave(fname, ims1)

    r = imageio.get_reader(fname)

    for i in (1, 0, 2, 0, 1, 2):
        assert np.all(ims1[i] == r.get_data(i))
    # Note that if we would not get the data of one image in the series,

im3 = imageio.imread(filename3)
    assert im1.ndim == 3
    assert im1.shape == im3.shape
    assert (im1 == im3).all()
    
    # Ensure imread + imwrite works round trip - volume like
    filename3 = os.path.join(test_dir, 'test_tiff2.tiff')
    im1 = imageio.volread(filename1)
    imageio.volwrite(filename3, im1)
    im3 = imageio.volread(filename3)
    assert im1.ndim == 4
    assert im1.shape == im3.shape
    assert (im1 == im3).all()

    # Read metadata
    md = imageio.get_reader(filename2).get_meta_data()
    assert md['is_imagej'] is None
    assert md['description'] == 'shape=(2,3,10,10)'
    assert md['description1'] == ''
    assert md['datetime'] == datetime.datetime(2015, 5, 9, 9, 8, 29)
    assert md['software'] == 'tifffile.py'

    # Write metadata
    dt = datetime.datetime(2018, 8, 6, 15, 35, 5)
    w = imageio.get_writer(filename1, software='testsoftware')
    w.append_data(np.zeros((10, 10)), meta={'description': 'test desc',
                                            'datetime': dt})
    w.close()
    r = imageio.get_reader(filename1)
    md = r.get_meta_data()
    assert 'datetime' in md
    assert md['datetime'] == dt

def test_request_file_no_seek():
    class File:
        def read(self, n):
            return b"\x00" * n

        def seek(self, i):
            raise IOError("Not supported")

        def tell(self):
            raise Exception("Not supported")

        def close(self):
            pass

    R = Request(File(), "ri")
    with raises(IOError):
        R.firstbytes

def test_select():

    fname1 = get_remote_file("images/cockatoo.mp4", test_dir)

    F = imageio.formats["avbin"]
    assert F.name == "AVBIN"

    assert F.can_read(core.Request(fname1, "rI"))
    assert not F.can_write(core.Request(fname1, "wI"))
    assert not F.can_read(core.Request(fname1, "ri"))
    assert not F.can_read(core.Request(fname1, "rv"))

# Test can read, cannot write
    assert format.can_read(Request(lfp_file, "ri"))

    # Test cannot read, cannot write
    assert not format.can_read(Request(lfp_file, "rv"))
    assert not format.can_read(Request(lfp_file, "rI"))
    assert not format.can_read(Request(lfp_file, "rV"))
    assert not format.can_read(Request(lfr_file, "ri"))
    assert not format.can_read(Request(raw_f01_file, "ri"))
    assert not format.can_read(Request(raw_illum_file, "ri"))
    assert not format.can_read(Request(png_file, "ri"))

    assert not format.can_write(Request(lfp_file, "wi"))
    assert not format.can_write(Request(lfr_file, "wi"))
    assert not format.can_write(Request(raw_f01_file, "wi"))
    assert not format.can_write(Request(raw_illum_file, "wi"))
    assert not format.can_write(Request(png_file, "wi"))