Image

class image.Image(filename=None)[source]

Bases: object

Constructor of the image object. If filename the load function loads the image file.

Parameters

filename (str (default=None)) – Image filename

add_single_batch()[source]

Add batch dimension for testing layer

Return type

self

property channels

Get the image number of channels

crop(dsize, size)[source]

Crop the image according to the given dimensions [dsize[0] : dsize[0] + size[0], dsize[1] : dsize[1] + size[1]]

Parameters
  • dsize (2D iterable) – (X, Y) of the crop

  • size (2D iterable) – (width, height) of the crop

Returns

cropped – Cropped image

Return type

Image

draw_detections(dets, thresh, names)[source]

Draw the detections into the current image

Parameters
  • dets (Detection list) – List of pre-computed detection objects

  • thresh (float) – Probability threshold to filter the boxes

  • names (iterable) – List of object names as strings

Return type

self

flip(axis=- 1)[source]

Flip the image along given axis (0 - horizontal, 1 - vertical)

Parameters

axis (int (default=0)) – Axis to flip

Return type

self

from_frame(array)[source]

Use opencv frame array as the image

from_numpy_matrix(array)[source]

Use numpy array as the image

Parameters

array (array_like) – buffer of the input image as (width, height, channel)

Return type

self

get()[source]

Return the data object as a numpy array

Returns

data – Image data as numpy array

Return type

array-like

property height

Get the image height

letterbox(net_dim)[source]

resize image with unchanged aspect ratio using padding

Parameters

net_dim (2D iterable) – width and height outputs

Returns

resized – Resized Image

Return type

Image

load(filename)[source]

Read Image from file

Parameters

filename (str) – Image filename path

Return type

self

mean_std_norm()[source]

Normalize the current image as

image = (image - mean) / variance
Return type

self

remove_single_batch()[source]

Remove batch dimension for testing layer

Return type

self

rescale(var, process=normalization.normalize)[source]

Divide or multiply by train variance-image

Parameters
  • variances (array_like) – Array of variances to apply to the image

  • process (normalization (int)) – Switch between normalization and denormalization

Return type

self

resize(dsize=None, scale_factor=(None, None))[source]

Resize the image according to the new shape given

Parameters
  • dsize (2D iterable (default=None)) – Destination size of the image

  • scale_factor (2D iterable (default=(None, None))) – width scale factor, height scale factor

Returns

res – Resized Image

Return type

Image

Notes

Note

The resize is performed using the LANCZOS interpolation.

rgb2rgba()[source]

Add alpha channel to the original image

Return type

self

Notes

Note

Pay attention to the value of the alpha channel! OpenCV does not set its values to null but they are and empty (garbage) array.

rotate(angle)[source]

Rotate the image according to the given angle in degree fmt.

Parameters

angle (float) – Angle in degree fmt

Returns

rotated – Rotated image

Return type

Image

Note

Note

This rotation preserves the original size so some original parts can be removed from the rotated image. See ‘rotate_bound’ for a conservative rotation.

References

https://www.pyimagesearch.com/2017/01/02/rotate-images-correctly-with-opencv-and-python/

rotate_bound(angle)[source]

Rotate the image according to the given angle in degree fmt.

Parameters

angle (float) – Angle in degree fmt

Returns

rotated – Rotated image

Return type

Image

Note

Note

This rotation preserves the original image, so the output can be greater than the original size. See ‘rotate’ for a rotation which preserves the size.

References

https://www.pyimagesearch.com/2017/01/02/rotate-images-correctly-with-opencv-and-python/

save(filename)[source]

save the image

Parameters

filename (str) – Output filename of the image

Return type

True if everything is ok

scale(scaling, process=normalization.normalize)[source]

Scale image values

Parameters
  • scale (float) – Scale factor to apply to the image

  • process (normalization (int, default = normalize)) – Switch between normalization (0) and denormalization (1)

Return type

self

scale_between(minimum, maximum)[source]

Rescale image value between min and max

Parameters
  • minimum (float (default = 0.)) – Min value

  • maximum (float (default = 1.)) – Max value

Return type

self

property shape

Get the image dimensions

show(window_name, ms=0, fullscreen=None)[source]

show the image

Parameters
  • window_name (str) – Name of the plot

  • ms (int (default=0)) – Milliseconds to wait

Returns

check – True if everything is ok

Return type

bool

standardize(means, process=normalization.normalize)[source]

Remove or add train mean-image from current image

Parameters
  • means (array_like) – Array of means to apply to the image

  • process (normalization (int, default = normalize)) – Switch between normalization (0) and denormalization (1)

Return type

self

transpose()[source]

Transpose width and height

Return type

self

property width

Get the image width