Kria™ KV260 Vision AI Starter Kit
Smart Camera Tutorial

Customizing the AI Models used in the application

Customizing the AI Models used in the application¶

Introduction¶

This document provides an overview of how to customize the default smartcam application to use other AI models.

Prerequisites¶

Other than the 3 models provided via command line option --aitask as documented here,

facedetect (densebox_320_320)
refinedet (refinedet_pruned_0_96)
ssd (ssd_adas_pruned_0_95)

customization can be made to use other Vitis AI models or retrained model by the users of the same class.

Model Preparation¶

Note The design currently only supports Vitis AI 1.3.0

Note As described in the Hardware Accelerator section, the DPU integrated in the platform uses the B3136 configuration.

The arch.json used to compile the xmodel for B3136 DPU can be obtained by build the accelerator, but if you won’t build all from the start, you can save following code as arch.json

{
    "fingerprint":"0x1000020F6014406"
}

For detailed instructions on obtaining an alternative model from the Xilinx model zoo or training, pruning, quantizing, and compiling a new model, please refer to the Vitis AI documentation.

Configuration files¶

To integrate a different .xmodel into the AIBox application, the following configuration files must be updated accordingly:

AI Inference Config:

Take the refinedet aiinference.json /opt/xilinx/share/ivas/smartcam/refinedet/aiinference.json as an example,

    {
        "ivas-library-repo": "/usr/lib/",
            "element-mode":"inplace",
            "kernels" :[
            {
                "library-name":"libivas_xdpuinfer.so",
                "config": {
                    "model-name" : "refinedet_pruned_0_96",
                    "model-class" : "REFINEDET",
                    "model-path" : "/opt/xilinx/share/vitis_ai_library/models/kv260-aibox-reid",
                    "run_time_model" : false,
                    "need_preprocess" : false,
                    "performance_test" : false,
                    "debug_level" : 0
                }
            }
            ]
    }

You can change the “model-name” and “model-path” fields to use the customized xmdel file at ${model-path}/${model-name}/${model-name}.xmodel.

Pay attention to the field “need_preprocess”, which is now “false”, tells Vitis AI Library the input buffer is already the resized and quantized BGR image as required by the model. And the preprocess is done by the preprocess plugin with the proper configuration which will be detailed in next section.

When you set the “need_preprocess” here to “true” for some reason, you should also make change to the process configuration to ask the preprocess IP works just as colour conversion and resizing.

Preprocess Config:

    "config": {
        "debug_level" : 1,
        "mean_r": 123,
        "mean_g": 117,
        "mean_b": 104,
        "scale_r": 1,
        "scale_g": 1,
        "scale_b": 1
    }

The configuration value of mean/scale for r/g/b channels should be the same as the ones specified in Vitis AI Model prototxt file. For example, following  is taken from /opt/xilinx/share/ivas/smartcam/refinedet/preprocess.json.

model {
name : "refinedet_480x360_5G"
    kernel {
    name: "refinedet_480x360_5G"
    mean: 104.0
    mean: 117.0
    mean: 123.0
    scale: 1.0
    scale: 1.0
    scale: 1.0
    }
}

Notice the channels sequence in the Vitis AI model prototxt file is B, G, R, not R, G, B, as the above samples show.

Next Steps¶

Go back to the KV260 SOM Smart camera design start page

References¶

Vitis AI User Guide UG1414

License¶

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License.

You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Kria™ KV260 Vision AI Starter KitSmart Camera Tutorial