3 lstm for ocr task

ocr_three_lstm.prototxt

# has 3 lstm layer
name: "ocr"

layer {
	name: "data"
	type: "OCRData"
	top: "data"
	top: "label"
	image_data_param {
		is_color: false
		source: "/home/[email protected]/exp/ocr/train_hard_list.txt"
		batch_size: 50 
	}
	transform_param {
		force_gray: true
		scale: 0.00390625
	}
	ocr_data_param {
		split_flag_file: "|"
		split_flag_number: ","
		label_size: 4
	}
}

layer {
	name: "permute_data"
	type: "Permute"
	bottom: "data"
	top: "permute_data"
	permute_param {
		order: 3
		order: 0
		order: 2
		order: 1
	}
}

layer {
	name: "indicator_generator"
	type: "TimeIndicator"
	top: "indicator"
	time_indicator_param {
		batch_size: 50
		time_step: 80
	}
}

layer {
	name: "lstm1"
	type: "LSTM"
	bottom: "permute_data"
	bottom: "indicator"
	top: "lstm1"
	recurrent_param {
		num_output: 100
		weight_filler {
			type: "xavier"
		}
		bias_filler {
			type: "constant"
			value: 0.0
		}
		debug_info: false
	}
}

layer {
	name: "lstm2"
	type: "LSTM"
	bottom: "lstm1"
	bottom: "indicator"
	top: "lstm2"
	recurrent_param {
		num_output: 100
		weight_filler {
			type: "xavier"
		}
		bias_filler {
			type: "constant"
			value: 0.0
		}
		debug_info: false
	}
}

layer {
	name: "lstm3"
	type: "LSTM"
	bottom: "lstm2"
	bottom: "indicator"
	top: "lstm3"
	recurrent_param {
		num_output: 100
		weight_filler {
			type: "xavier"
		}
		bias_filler {
			type: "constant"
			value: 0.0
		}
		debug_info: false
	}
}

layer {
  name: "fc"
  type: "InnerProduct"
  bottom: "lstm3"
  top: "fc"
  param {
    lr_mult: 1
    decay_mult: 1
  }
  param {
    lr_mult: 2
    decay_mult: 0
  }
  inner_product_param {
    num_output: 11
	axis: 2
    weight_filler {
      type: "xavier"
    }
    bias_filler {
      type: "constant"
      value: 0
    }
  }
}

layer {
	name: "ctc_loss"
	type: "CtcLoss"
	bottom: "fc"
	bottom: "label"
	top: "ctc_loss"
	loss_weight: 1.0
	ctc_loss_param {
		blank: 0
		label_length: 4
		alphabet_size: 11
	}
}