image-dataset-viz 0.2

# ImageDatasetViz
[](https://travis-ci.org/vfdev-5/ImageDatasetViz)
[](https://coveralls.io/github/vfdev-5/ImageDatasetViz?branch=master)

Observe dataset of images and targets in few shots


## Descriptions

Idea is to create tools to store images, targets from a dataset as a few large images to observe the dataset
in few shots.


## Installation

```bash
python setup.py install
```
or
```bash
pip install git+https://github.com/vfdev-5/ImageDatasetViz.git
```

## Usage

### Render a single datapoint

First, we can just take a look on a single data point rendering. Let's assume that we
have `img` as, for example, `PIL.Image` and `target` as acceptable target type (`str` or list of points or
`PIL.Image` mask, etc), thus we can generate a single image with target.

```python
from image_dataset_viz import render_datapoint

# if target is a simple label
res = render_datapoint(img, "test label", text_color=(0, 255, 0), text_size=10)
plt.imshow(res)

# if target is a mask image (PIL.Image)
res = render_datapoint(img, target, blend_alpha=0.5)
plt.imshow(res)

# if target is a bounding box, e.g. np.array([[10, 10], [55, 10], [55, 77], [10, 77]])
res = render_datapoint(img, target, geom_color=(255, 0, 0))
plt.imshow(res)
```

#### Example output on Leaf Segmentation dataset from CVPPP2017

  

### Export complete dataset
For example, we have a dataset of image files and annotations files (polygons with labels):
```python
img_files = [
'/path/to/image_1.ext',
'/path/to/image_2.ext',
...
'/path/to/image_1000.ext',
]
target_files = [
'/path/to/target_1.ext2',
'/path/to/target_2.ext2',
...
'/path/to/target_1000.ext2',
]
```
We can produce a single image composed of 20x50 small samples with targets to better visualize the whole dataset.
Let's assume that we do need a particular processing to open the images in RGB 8bits format:
```python
from PIL import Image

def read_img_fn(img_filepath):
return Image.open(img_filepath).convert('RGB')
```
and let's say the annotations are just lines with points and a label, e.g. `12 23 34 45 56 67 car`
```python
from pathlib import Path
import numpy as np

def read_target_fn(target_filepath):
with Path(target_filepath).open('r') as handle:
points_labels = []
while True:
line = handle.readline()
if len(line) == 0:
break
splt = line[:-1].split(' ') # Split into points and labels
label = splt[-1]
points = np.array(splt[:-1]).reshape(-1, 2)
points_labels.append((points, label))
return points_labels
```
Now we can export the dataset
```python
de = DatasetExporter(read_img_fn=read_img_fn, read_target_fn=read_target_fn,
img_id_fn=lambda fp: Path(fp).stem, n_cols=20)
de.export(img_files, target_files, output_folder="dataset_viz")
```
and thus we should obtain a single png image with composed of 20x50 small samples.


## Examples

- [CIFAR10](examples/example_CIFAR10.ipynb)
- [VEDAI](examples/example_VEDAI.ipynb)