Image Caption Generator

Issues Forks Stars Ajay Dabas

A neural network to generate captions for an image using CNN and RNN with BEAM Search.

Examples

Example of Image Captioning

Image Credits : Towardsdatascience

Table of Contents

  1. Requirements
  2. Training parameters and results
  3. Generated Captions on Test Images
  4. Procedure to Train Model
  5. Procedure to Test on new images
  6. Configurations (config.py)
  7. Frequently encountered problems
  8. TODO
  9. References

1. Requirements

Recommended System Requirements to train model.

Required libraries for Python along with their version numbers used while making & testing of this project

Flickr8k Dataset: Dataset Request Form

UPDATE (April/2019): The official site seems to have been taken down (although the form still works). Here are some direct download links:

Important: After downloading the dataset, put the reqired files in train_val_data folder

2. Training parameters and results

NOTE

Model & Config Argmax BEAM Search
InceptionV3 + AlternativeRNN
  • Epochs = 20
  • Batch Size = 64
  • Optimizer = Adam
    Crossentropy loss
    (Lower the better)
  • loss(train_loss): 2.4050
  • val_loss: 3.0527
    • BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.596818
  • BLEU-2: 0.356009
  • BLEU-3: 0.252489
  • BLEU-4: 0.129536
    k = 3

    BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.606086
  • BLEU-2: 0.359171
  • BLEU-3: 0.249124
  • BLEU-4: 0.126599
InceptionV3 + RNN
  • Epochs = 11
  • Batch Size = 64
  • Optimizer = Adam
    Crossentropy loss
    (Lower the better)
  • loss(train_loss): 2.5254
  • val_loss: 3.1769
    • BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.601791
  • BLEU-2: 0.344289
  • BLEU-3: 0.230025
  • BLEU-4: 0.108898
    k = 3

    BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.605097
  • BLEU-2: 0.356094
  • BLEU-3: 0.251132
  • BLEU-4: 0.129900
VGG16 + AlternativeRNN
  • Epochs = 18
  • Batch Size = 64
  • Optimizer = Adam
    Crossentropy loss
    (Lower the better)
  • loss(train_loss): 2.2880
  • val_loss: 3.1889
    • BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.596655
  • BLEU-2: 0.342127
  • BLEU-3: 0.229676
  • BLEU-4: 0.108707
    k = 3

    BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.593876
  • BLEU-2: 0.348569
  • BLEU-3: 0.242063
  • BLEU-4: 0.123221
VGG16 + RNN
  • Epochs = 7
  • Batch Size = 64
  • Optimizer = Adam
    Crossentropy loss
    (Lower the better)
  • loss(train_loss): 2.6297
  • val_loss: 3.3486
    • BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.557626
  • BLEU-2: 0.317652
  • BLEU-3: 0.216636
  • BLEU-4: 0.105288
    k = 3

    BLEU Scores on Validation data
    (Higher the better)
  • BLEU-1: 0.568993
  • BLEU-2: 0.326569
  • BLEU-3: 0.226629
  • BLEU-4: 0.113102

3. Generated Captions on Test Images

Model used - InceptionV3 + AlternativeRNN

Image Caption
Image 1
  • Argmax: A man in a blue shirt is riding a bike on a dirt path.
  • BEAM Search, k=3: A man is riding a bicycle on a dirt path.
Image 2
  • Argmax: A man in a red kayak is riding down a waterfall.
  • BEAM Search, k=3: A man on a surfboard is riding a wave.

4. Procedure to Train Model

  1. Clone the repository to preserve directory structure.
    git clone https://github.com/dabasajay/Image-Caption-Generator.git
  2. Put the required dataset files in train_val_data folder (files mentioned in readme there).
  3. Review config.py for paths and other configurations (explained below).
  4. Run train_val.py.

5. Procedure to Test on new images

  1. Clone the repository to preserve directory structure.
    git clone https://github.com/dabasajay/Image-Caption-Generator.git
  2. Train the model to generate required files in model_data folder (steps given above).
  3. Put the test images in test_data folder.
  4. Review config.py for paths and other configurations (explained below).
  5. Run test.py.

6. Configurations (config.py)

config

  1. images_path :- Folder path containing flickr dataset images
  2. train_data_path :- .txt file path containing images ids for training
  3. val_data_path :- .txt file path containing imgage ids for validation
  4. captions_path :- .txt file path containing captions
  5. tokenizer_path :- path for saving tokenizer
  6. model_data_path :- path for saving files related to model
  7. model_load_path :- path for loading trained model
  8. num_of_epochs :- Number of epochs
  9. max_length :- Maximum length of captions. This is set manually after training of model and required for test.py
  10. batch_size :- Batch size for training (larger will consume more GPU & CPU memory)
  11. beam_search_k :- BEAM search parameter which tells the algorithm how many words to consider at a time.
  12. test_data_path :- Folder path containing images for testing/inference
  13. model_type :- CNN Model type to use -> inceptionv3 or vgg16
  14. random_seed :- Random seed for reproducibility of results

rnnConfig

  1. embedding_size :- Embedding size used in Decoder(RNN) Model
  2. LSTM_units :- Number of LSTM units in Decoder(RNN) Model
  3. dense_units :- Number of Dense units in Decoder(RNN) Model
  4. dropout :- Dropout probability used in Dropout layer in Decoder(RNN) Model

7. Frequently encountered problems

8. TODO

9. References