# Model Parameters When loading a model with **`zoo.loadModel()`** you can supply an **`options`** object that lets you control various functionalities of the model. You can also set these parameters on a model instance after it has been loaded. ## Model Parameters The following parameters can be configured to control the behavior of the model, including preprocessing, post-processing, and connection settings. Parameters are categorized by their effect: * **JSON-only parameters**: These are passed directly to the server as model configuration and do not directly alter the JavaScript SDK's model class behavior. * **Model-only parameters**: These exclusively affect the model class's behavior within the JavaScript SDK and are not sent to the server. * **Hybrid parameters**: These both influence the model class's functionality in JavaScript and are also set in the model parameter JSON sent to the server. | Parameter Name | Description | Type | Valid Values / Constraints | Category | | ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ----------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------- | | `deviceType` | Specifies the target device type for inference. This can be a single device or an array of preferred devices. The SDK will attempt to use the first supported device in the list. | `string` or `Array` | Examples: `'RUNTIME/DEVICE'` (e.g., `'OPENVINO/CPU'`) or `['RUNTIME1/DEVICE1', 'RUNTIME2/DEVICE2']`. Must be a device type supported by the model and available on the system. | Hybrid | | `labelWhitelist` | An array of strings. If set, only detection labels present in this list will be displayed in the overlay. | `Array` | An array of strings, e.g., `['person', 'car']`. | Model-only | | `labelBlacklist` | An array of strings. If set, detection labels present in this list will be excluded from the overlay. | `Array` | An array of strings, e.g., `['background', 'noise']`. | Model-only | | `overlayColor` | Sets the color(s) used for drawing bounding boxes, labels, and segmentation masks. Can be a single RGB triplet `[R, G, B]` or an array of such triplets `[[R1, G1, B1], [R2, G2, B2]]` for cycling through colors. Defaults to auto-generated colors. | `Array` or `Array>` | Numbers between 0 and 255 for RGB components. Example: `[255, 0, 0]` for red, or `[[255, 0, 0], [0, 255, 0]]`. | Model-only | | `overlayLineWidth` | Sets the line width (in pixels) for drawing bounding boxes and connections in pose detection. | `number` | A positive number, e.g., `3`. | Model-only | | `overlayShowLabels` | A boolean value. If `true`, labels (e.g., class names) will be displayed in the overlay. | `boolean` | `true` or `false`. | Model-only | | `overlayShowProbabilities` | A boolean value. If `true`, probabilities or confidence scores will be displayed alongside labels in the overlay. | `boolean` | `true` or `false`. | Model-only | | `overlayAlpha` | Sets the transparency percentage of the overlay elements (bounding boxes, masks, etc.). | `number` | A number between 0 (fully transparent) and 1 (fully opaque). | Model-only | | `overlayFontScale` | Sets the scaling factor for the font size of text displayed in the overlay. | `number` | A positive number, e.g., `1.5` for 150% size. | Model-only | | `inputLetterboxFillColor` | Sets the RGB fill color used for letterboxing when the `inputPadMethod` is set to `'letterbox'`. | `Array` | An array of 3 numbers between 0 and 255, e.g., `[0, 0, 0]` for black. | Model-only | | `inputPadMethod` | Specifies the method used to resize and pad the input image to match the model's expected input dimensions. | `string` | One of: `'stretch'`, `'letterbox'`, `'crop-first'`, or `'crop-last'`. | Model-only | | `saveModelImage` | A boolean value. If `true`, the preprocessed image (as a Blob) that was sent to the model will be included in the result object. | `boolean` | `true` or `false`. | Model-only | | `inputCropPercentage` | For `'crop-first'` and `'crop-last'` padding methods, this specifies the percentage of the image to crop. | `number` | A number between 0 and 1. | Model-only | | `autoScaleDrawing` | A boolean value. If `true`, overlay elements like font size and line width will automatically scale based on the display canvas size to maintain visual consistency. | `boolean` | `true` or `false`. | Model-only | | `targetDisplayWidth` | Reference width (in pixels) used for `autoScaleDrawing`. This helps determine the scaling factor for overlay elements. | `number` | A number representing the target width, defaults to `1920`. | Model-only | | `targetDisplayHeight` | Reference height (in pixels) used for `autoScaleDrawing`. This helps determine the scaling factor for overlay elements. | `number` | A number representing the target height, defaults to `1080`. | Model-only | | `cloudToken` | Sets the authentication token required for connecting to the DeGirum cloud inference service. | `string` | A valid authentication token string. | JSON-only | | `cloudURL` | Sets the base URL for the DeGirum cloud server. | `string` | A valid URL string, e.g., `'https://cloud.degirum.com'`. | JSON-only | | `outputConfidenceThreshold` | Sets the minimum confidence score (probability) for a detection or classification to be included in the model's output. Results below this threshold are filtered out. | `number` | A number between 0 and 1. | JSON-only | | `outputMaxDetections` | Sets the maximum total number of detections that the model should return for a single inference. | `number` | An integer. | JSON-only | | `outputMaxDetectionsPerClass` | Sets the maximum number of detections allowed per individual class. | `number` | An integer. | JSON-only | | `outputMaxClassesPerDetection` | Sets the maximum number of classes to report for each detected object. Useful for models that can classify a single detection into multiple categories. | `number` | An integer. | JSON-only | | `outputNmsThreshold` | Sets the Non-Maximum Suppression (NMS) Intersection Over Union (IOU) threshold. This parameter is used to filter overlapping bounding boxes, keeping only the most confident ones. | `number` | A number between 0 and 1. | JSON-only | | `outputPostprocessType` | Specifies the type of post-processing to apply to the model's raw output. This dictates how the model's predictions are interpreted and formatted. | `string` | One of: `'None'`, `'Base'`, `'Classification'`, `'MultiLabelClassification'`, `'Detection'`, `'DetectionYolo'`, `'DetectionYoloV8'`, `'DetectionYoloV10'`, `'DetectionYoloPlates'`, `'DetectionYoloV8Plates'`, `'FaceDetection'`, `'PoseDetection'`, `'PoseDetectionYoloV8'`, `'HandDetection'`, `'Segmentation'`, `'SegmentationYoloV8`, `Dequantization`, `Null`. | JSON-only | | `outputTopK` | For classification models, this parameter specifies the number of top predictions (classes with the highest confidence scores) to return. | `number` | An integer. | JSON-only | | `outputUseRegularNms` | A boolean value. If `true`, the model will use regular Non-Maximum Suppression (NMS); otherwise, it may use a faster, approximate NMS algorithm. | `boolean` | `true` or `false`. | JSON-only | | `measureTime` | A boolean value. If `true`, enables detailed performance timing statistics for various stages of the inference process (client-side preprocessing, server-side inference, client-side post-processing). These statistics can be retrieved using `getTimeStats()` and `printLatencyInfo()`. | `boolean` | `true` or `false`. | Hybrid | | `eagerBatchSize` | Sets the batch size for eager execution, influencing how many frames are processed together in a single batch. | `number` | A positive integer. | JSON-only | | `outputPoseThreshold` | Sets the confidence threshold for individual keypoints in pose detection results. Keypoints with scores below this threshold may be filtered out. | `number` | A number between 0 and 1. | JSON-only | | `inputShape` | Defines the expected input shape(s) for the model. This can be an array of arrays, where each inner array represents the dimensions (N, H, W, C) for a specific input. | `Array>` | An array of integer arrays, e.g., `[[1, 224, 224, 3]]` for a single input of batch size 1, height 224, width 224, and 3 channels. | Hybrid |