SignLLM: Sign Languages Production Large Language Models
Sen Fang1
Lei Wang2,3
Ce Zheng4
Yapeng Tian5
Chen Chen6

1Rutgers University
2Australian National University
4Carnegie Mellon University
5University of Texas at Dallas
6University of Central Florida

Overview: (left) We present examples and descriptions of various parts of our Prompt2Sign dataset; (right) Our SignLLM bilingual sign language production methods, operating mechanisms and demonstration, and different ways.


Prompt2Sign (tools)

Additional details


Code (Coming soon)


  In this paper, we introduce the first comprehensive multilingual sign language dataset named Prompt2Sign, which builds from public sign language data including American Sign Language (ASL) and seven others. Our dataset transforms a vast array of videos into a streamlined, model-friendly format, optimized for training with translation models like seq2seq and text2text. Building on this new dataset, we propose SignLLM, the first multilingual Sign Language Production (SLP) model, which includes two novel multilingual SLP modes that allow for the generation of sign language gestures from input text or prompt. Both of the modes can use a new loss and a module based on reinforcement learning, which accelerates the training by enhancing the model's capability to autonomously sample high-quality data. We present benchmark results of SignLLM, which demonstrate that our model achieves state-of-the-art performance on SLP tasks across eight sign languages.

Demo Video

(a) The control surface on the wing, which is operated by horizontally shifting the stick to the right and left, enables lateral movement. (b) Allow me to demonstrate the correct form for a proper pike position. (c) Allow me to showcase this demonstration on my back as it is much more convenient.
DEMO: We give some examples of better prediction results, below each video is their input text.

Presentation under Ideal Future Conditions

(input) Another technique in your life is you can braid the hair on first and then start wrapping cause some people have really short hair and we can create the look with adding the hair end. (input) So we are currently heating up the oil and at this point. (input) First of all Massage Parlor is a very dated term and often has some negative connotations that are associated with it and as a massage therapist we worked hard to kind of steer away from that.
(input) They're going to stay exactly where they are and feeling my shoulder. (input) For a very small intricate design like an "i" you're going to want. (input) If you want to release him.
(input) We're going to look at it from several aspects. (input) And you know when we got to that. (input) And what they do is every time they're writing from that.
QP: Synthetic sign language video obtained after processing using a style transfer model (the intermediate input video has undergone some reprocessing, such as acceleration, rendering or others).

Note: These videos are not direct output from our model and actually a lot of trouble to make, they are just for demonstration purposes. These videos are the result of reprocessing the pose videos output of our model using the style transfer model, a lot of the media spontaneously exaggerate our work, it is not what we want to see. The use of images processed by style transfer models for qualitative presentation is a common practice in previous SLP and may not be well known to people in other fields.

Dataset and Main Methods

(left) An overview of the structure and form of PROMPT2SIGN dataset. (middle) The interaction principle of Text2LangGloss and MLSF, computational methods with reinforcement learning. (right) The output of SIGNLLM can be converted into most pose representation formats, which can then be rendered into realistic human appearance by style transfer/specifically fine-tuned generative model.

Other Method

In our work, we have improved upon the Text2Gloss framework by incorporating a marker that produces Gloss with the necessary linguistic attributes, while also representing profound characteristics through variables Vt and Xu within neural networks. Additionally, we have introduced five key elements—user, agent, environment, iterative update process, and PLC—which collectively outline a reinforcement learning process tailored for sequence prediction.
Reinforcement Learning Process Text to Language Gloss Framework

Empirical Studies and Analysis

(1) American Sign Language Production (ASLP).

Comparison of different models of SIGNLLM with baseline. Models M and T represent MLSF and Text2LangGloss trained ASLP models, respectively.

(2) German Sign Language Production (GSLP).

Comparison of different models of SIGNLLM with previous work.

(3) Ablation Study.

SignLLM-40M-Base results for Text to Pose on the ASL part of PROMPT2SIGN, with multiple data augmentation techniques. Base: Multi-Language Switching Framework with Normal MSE Loss, FP: Future Prediction, GN: Gaussian Noise, Text2LangGloss: Text2LangGloss with Normal MSE Loss, PLC: Priority Learning Channe

(4) Training Efficiency Study.

the comparison of the effect of different Settings on DTW values (the lower the better) at different times is determined by epoch.





[2024.05.17] The arXiv version of the paper is now available.
[2024.01.16] Prompt2Sign homepage is available and data is expected to be released after accept (maybe at the end of 2024, so don't rush).
[2023.12.14] We have made supplementary materials and demo available at this page.
[2023.11.04] We have made Prompt2Sign and Tools available at GitHub. Check out here.


Q0: License issue:
A0: The Prompt2Sign and SignLLM are copyright by us and published under the Creative Commons Attribution-NonCommercial 4.0 International License.
Q1: Some links are invalid on page. How can I obtain the missing information?
Q1: I am located in mainland China and I cannot access Google Driver. How can I get the dataset?
A1: Please submit a GitHub issue at Any repository of user "SignLLM". We may reach you shortly.
Q2: Is the data in the data set complete relative to the original video? I feel like it's smaller than the actual data set.
A2: We're using a dataset that is a subset of the video clips that correspond to the lines and then we compress those clips. Compression to 1/5 of the original size refers to 1/5 of the size of the clip.
Q3: Can we fully achieve the actual effect in the paper or presentation?
A3: No, according to the data and the actual situation, most of our cases are not up to the level of use. Dynamic or static display, we are selected to show the best effect. Q4: How to complete the data conversion format? Specific to the level of each number. Too much remains unclear.
A4: You can look at the dataset itself and the tools, with an example and plenty of text describing it in detail.

How to finish data format conversion (JSON->Ours)?

Below, we show an example JSON:
### JSON file:
    "version": 1.3,
    "people": [
            "person_id": [
            "pose_keypoints_2d": [
	        # We only get eight key points in the upper body(24 number).
            "face_keypoints_2d": [
                # We don't train the face.
            "hand_left_keypoints_2d": [
		# 21 key points, 63 values.
            "hand_right_keypoints_2d": [
		// 21 key points, 63 values.
            "pose_keypoints_3d": [],
            "face_keypoints_3d": [],
            "hand_left_keypoints_3d": [],
            "hand_right_keypoints_3d": []

How to extract key points? We extracted two-dimensional (2D) frontal human pose information from videos of different resolutions, including upper body pose information of the body and hands, through OpenPose. Includes 8 upper body key points. 21 keypoints in each hand, which is a total of 42 hand keypoints. These two parts add up to fifty keypoints, each of which has three XYZ messages, or 150 numbers.

Then in steps ``json (2D keypoints) to h5'', ``h5 to txt (3D keypoints)'', and ``txt to skels (Standard Pose Storage)'':

How to complete ``json to h5''? We successively obtain a json number in a folder (a frame of pose information, 50 key points, 150 numbers), and then read all the json numbers in a folder into the key name of an h5 (h5 is a format of numpy) file, multiple folders form multiple build names, and finally form an h5 file.

How to complete ``h5 to txt''? We read each key name of h5 in turn (the original folder name), create the corresponding folder, each folder generates 5 txt files, the last one is the result, the first 4 txt stores the intermediate variable. This is the part of 2D to 3D, and the key formula 3 in the text is the formula of this part. Additionally, we read the relevant data and delete the unqualified data such as NaN, 0, or replace it with the average median of the data. Finally, we condensed the data to about 1/5 of the original, this data comes from the processing of ASL part.

How to complete ``txt to skels''? We read the fifth txt file of each folder in turn, the number of lines in the txt file represents the number of frames of the folder corresponding to the video, we read a line of txt (150 numbers, separated by Spaces, a frame of information), plus a space, and then add a count value (the current line divided by the total number of lines, representing the progress bar), add a space after the count value, Then add the second line txt and continue to repeat the above. Then we put a txt (a video information, the total number of numbers in it = 151* video frames) into a line of content, in turn, tens of thousands of videos are all stored in our standard format.

How to complete h5 to txt conversion?

Above you mentioned TXT folder 12345, but what is TXT5? Below, we show an example the above data processing process:
def getTXT(key, fnameIn, i, mode):
  output_file = f"out_data/{mode}/{key}/demo5.txt"
  if os.path.exists(output_file):
            print(f"Skipping {key} as output file already exists.")
      # Getting our structure of skeletal model.
      # For customizing the structure see a definition of getSkeletalModelStructure. 
      dtype = "float32"
      randomNubersGenerator = numpy.random.RandomState(1234) 
      structure = skeletalModel.getSkeletalModelStructure()
      with h5py.File(fnameIn, "r") as hfIn:
            print("Now is processing the "+ key)
            inputSequence_2D = numpy.array(hfIn.get(key))

            # Decomposition of the single matrix into three matrices: x, y, w (=likelihood)
            X = inputSequence_2D
            Xx = X[0:X.shape[0], 0:(X.shape[1]):3]
            Xy = X[0:X.shape[0], 1:(X.shape[1]):3]
            Xw = X[0:X.shape[0], 2:(X.shape[1]):3]

            # Normalization of the picture (x and y axis has the same scale)
            Xx, Xy = pose2D.normalization(Xx, Xy)
            save(f"out_data/{mode}/{key}/demo1.txt", [Xx, Xy, Xw])

            # Delete all skeletal models which have a lot of missing parts.
            Xx, Xy, Xw = pose2D.prune(Xx, Xy, Xw, (0, 1, 2, 3, 4, 5, 6, 7), 0.3, dtype)
            save(f"out_data/{mode}/{key}/demo2.txt", [Xx, Xy, Xw])

            # Preliminary filtering: weighted linear interpolation of missing points.
            Xx, Xy, Xw = pose2D.interpolation(Xx, Xy, Xw, 0.99, dtype)
            save(f"out_data/{mode}/{key}/demo3.txt", [Xx, Xy, Xw])

            # Initial 3D pose estimation
            ... = pose2Dto3D.initialization(
            save(f"out_data/{mode}/{key}/demo4.txt", [Yx0, Yy0, Yz0])

              # Backpropagation-based filtering
            Yx, Yy, Yz = pose3D.backpropagationBasedFiltering(
            save(f"out_data/{mode}/{key}/demo5.txt", [Yx, Yy, Yz])
            # Called after each folder is processed to release GPU resources
            print(f"Now we're working on folder {i} th, and will be finished")
The above code shows the contents of our several TXT files, and it clearly shows that 1234 is mainly to store intermediate variables and related content, the fifth folder is the final product we need. And for more details, see the official documentation.


SignLLM: Sign Languages Production Large Language Models
arXiv, 2024.
(Additional Details/
Supplementary Materials


      title={SignLLM: Sign Languages Production Large Language Models}, 
      author={Sen Fang and Lei Wang and Ce Zheng and Yapeng Tian and Chen Chen},


We sincerely appreciate the previous work, open source tools, and researchers for underserved populations. We stand on the shoulders of their work to achieve further achievements. Readers can learn how we utilize and improve previous work through our citations.

Additionally, we have noticed spontaneous promotion from over thirty marketing media outlets or individual accounts working for us, but they may have some misconceptions or exaggerations about our model. Our model takes input text or prompts to generate videos of sign language pose in various languages. Certain conditions need to be input into the model for further processing to obtain the final videos, so we need to work even harder to strengthen the end-to-end capabilities (ie, the pose video output from the model needs to be processed to achieve the effect of real people, and we never said that we could export real people directly).


For further questions and suggestions, please only contact Sen Fang or SignLLM.