1import math
2import numpy as np
3import torch
4import torchvision.transforms as T
5from decord import VideoReader, cpu
6from PIL import Image
7from torchvision.transforms.functional import InterpolationMode
8from transformers import AutoModel, AutoTokenizer
9
10IMAGENET_MEAN = (0.485, 0.456, 0.406)
11IMAGENET_STD = (0.229, 0.224, 0.225)
12
13def build_transform(input_size):
14 MEAN, STD = IMAGENET_MEAN, IMAGENET_STD
15 transform = T.Compose([
16 T.Lambda(lambda img: img.convert('RGB') if img.mode != 'RGB' else img),
17 T.Resize((input_size, input_size), interpolation=InterpolationMode.BICUBIC),
18 T.ToTensor(),
19 T.Normalize(mean=MEAN, std=STD)
20 ])
21 return transform
22
23def find_closest_aspect_ratio(aspect_ratio, target_ratios, width, height, image_size):
24 best_ratio_diff = float('inf')
25 best_ratio = (1, 1)
26 area = width * height
27 for ratio in target_ratios:
28 target_aspect_ratio = ratio[0] / ratio[1]
29 ratio_diff = abs(aspect_ratio - target_aspect_ratio)
30 if ratio_diff < best_ratio_diff:
31 best_ratio_diff = ratio_diff
32 best_ratio = ratio
33 elif ratio_diff == best_ratio_diff:
34 if area > 0.5 * image_size * image_size * ratio[0] * ratio[1]:
35 best_ratio = ratio
36 return best_ratio
37
38def dynamic_preprocess(image, min_num=1, max_num=12, image_size=448, use_thumbnail=False):
39 orig_width, orig_height = image.size
40 aspect_ratio = orig_width / orig_height
41
42 # calculate the existing image aspect ratio
43 target_ratios = set(
44 (i, j) for n in range(min_num, max_num + 1) for i in range(1, n + 1) for j in range(1, n + 1) if
45 i * j <= max_num and i * j >= min_num)
46 target_ratios = sorted(target_ratios, key=lambda x: x[0] * x[1])
47
48 # find the closest aspect ratio to the target
49 target_aspect_ratio = find_closest_aspect_ratio(
50 aspect_ratio, target_ratios, orig_width, orig_height, image_size)
51
52 # calculate the target width and height
53 target_width = image_size * target_aspect_ratio[0]
54 target_height = image_size * target_aspect_ratio[1]
55 blocks = target_aspect_ratio[0] * target_aspect_ratio[1]
56
57 # resize the image
58 resized_img = image.resize((target_width, target_height))
59 processed_images = []
60 for i in range(blocks):
61 box = (
62 (i % (target_width // image_size)) * image_size,
63 (i // (target_width // image_size)) * image_size,
64 ((i % (target_width // image_size)) + 1) * image_size,
65 ((i // (target_width // image_size)) + 1) * image_size
66 )
67 # split the image
68 split_img = resized_img.crop(box)
69 processed_images.append(split_img)
70 assert len(processed_images) == blocks
71 if use_thumbnail and len(processed_images) != 1:
72 thumbnail_img = image.resize((image_size, image_size))
73 processed_images.append(thumbnail_img)
74 return processed_images
75
76def load_image(image_file, input_size=448, max_num=12):
77 image = Image.open(image_file).convert('RGB')
78 transform = build_transform(input_size=input_size)
79 images = dynamic_preprocess(image, image_size=input_size, use_thumbnail=True, max_num=max_num)
80 pixel_values = [transform(image) for image in images]
81 pixel_values = torch.stack(pixel_values)
82 return pixel_values
83
84def split_model(model_name):
85 device_map = {}
86 world_size = torch.cuda.device_count()
87 config = AutoConfig.from_pretrained(model_path, trust_remote_code=True)
88 num_layers = config.llm_config.num_hidden_layers
89 # Since the first GPU will be used for ViT, treat it as half a GPU.
90 num_layers_per_gpu = math.ceil(num_layers / (world_size - 0.5))
91 num_layers_per_gpu = [num_layers_per_gpu] * world_size
92 num_layers_per_gpu[0] = math.ceil(num_layers_per_gpu[0] * 0.5)
93 layer_cnt = 0
94 for i, num_layer in enumerate(num_layers_per_gpu):
95 for j in range(num_layer):
96 device_map[f'language_model.model.layers.{layer_cnt}'] = i
97 layer_cnt += 1
98 device_map['vision_model'] = 0
99 device_map['mlp1'] = 0
100 device_map['language_model.model.tok_embeddings'] = 0
101 device_map['language_model.model.embed_tokens'] = 0
102 device_map['language_model.output'] = 0
103 device_map['language_model.model.norm'] = 0
104 device_map['language_model.model.rotary_emb'] = 0
105 device_map['language_model.lm_head'] = 0
106 device_map[f'language_model.model.layers.{num_layers - 1}'] = 0
107
108 return device_map
109
110# If you set `load_in_8bit=True`, you will need two 80GB GPUs.
111# If you set `load_in_8bit=False`, you will need at least three 80GB GPUs.
112path = 'OpenGVLab/InternVL3-2B'
113device_map = split_model('InternVL3-2B')
114model = AutoModel.from_pretrained(
115 path,
116 torch_dtype=torch.bfloat16,
117 load_in_8bit=False,
118 low_cpu_mem_usage=True,
119 use_flash_attn=True,
120 trust_remote_code=True,
121 device_map=device_map).eval()
122tokenizer = AutoTokenizer.from_pretrained(path, trust_remote_code=True, use_fast=False)
123
124# set the max number of tiles in `max_num`
125pixel_values = load_image('./examples/image1.jpg', max_num=12).to(torch.bfloat16).cuda()
126generation_config = dict(max_new_tokens=1024, do_sample=True)
127
128# pure-text conversation (纯文本对话)
129question = 'Hello, who are you?'
130response, history = model.chat(tokenizer, None, question, generation_config, history=None, return_history=True)
131print(f'User: {question}\nAssistant: {response}')
132
133question = 'Can you tell me a story?'
134response, history = model.chat(tokenizer, None, question, generation_config, history=history, return_history=True)
135print(f'User: {question}\nAssistant: {response}')
136
137# single-image single-round conversation (单图单轮对话)
138question = '<image>\nPlease describe the image shortly.'
139response = model.chat(tokenizer, pixel_values, question, generation_config)
140print(f'User: {question}\nAssistant: {response}')
141
142# single-image multi-round conversation (单图多轮对话)
143question = '<image>\nPlease describe the image in detail.'
144response, history = model.chat(tokenizer, pixel_values, question, generation_config, history=None, return_history=True)
145print(f'User: {question}\nAssistant: {response}')
146
147question = 'Please write a poem according to the image.'
148response, history = model.chat(tokenizer, pixel_values, question, generation_config, history=history, return_history=True)
149print(f'User: {question}\nAssistant: {response}')
150
151# multi-image multi-round conversation, combined images (多图多轮对话,拼接图像)
152pixel_values1 = load_image('./examples/image1.jpg', max_num=12).to(torch.bfloat16).cuda()
153pixel_values2 = load_image('./examples/image2.jpg', max_num=12).to(torch.bfloat16).cuda()
154pixel_values = torch.cat((pixel_values1, pixel_values2), dim=0)
155
156question = '<image>\nDescribe the two images in detail.'
157response, history = model.chat(tokenizer, pixel_values, question, generation_config,
158 history=None, return_history=True)
159print(f'User: {question}\nAssistant: {response}')
160
161question = 'What are the similarities and differences between these two images.'
162response, history = model.chat(tokenizer, pixel_values, question, generation_config,
163 history=history, return_history=True)
164print(f'User: {question}\nAssistant: {response}')
165
166# multi-image multi-round conversation, separate images (多图多轮对话,独立图像)
167pixel_values1 = load_image('./examples/image1.jpg', max_num=12).to(torch.bfloat16).cuda()
168pixel_values2 = load_image('./examples/image2.jpg', max_num=12).to(torch.bfloat16).cuda()
169pixel_values = torch.cat((pixel_values1, pixel_values2), dim=0)
170num_patches_list = [pixel_values1.size(0), pixel_values2.size(0)]
171
172question = 'Image-1: <image>\nImage-2: <image>\nDescribe the two images in detail.'
173response, history = model.chat(tokenizer, pixel_values, question, generation_config,
174 num_patches_list=num_patches_list,
175 history=None, return_history=True)
176print(f'User: {question}\nAssistant: {response}')
177
178question = 'What are the similarities and differences between these two images.'
179response, history = model.chat(tokenizer, pixel_values, question, generation_config,
180 num_patches_list=num_patches_list,
181 history=history, return_history=True)
182print(f'User: {question}\nAssistant: {response}')
183
184# batch inference, single image per sample (单图批处理)
185pixel_values1 = load_image('./examples/image1.jpg', max_num=12).to(torch.bfloat16).cuda()
186pixel_values2 = load_image('./examples/image2.jpg', max_num=12).to(torch.bfloat16).cuda()
187num_patches_list = [pixel_values1.size(0), pixel_values2.size(0)]
188pixel_values = torch.cat((pixel_values1, pixel_values2), dim=0)
189
190questions = ['<image>\nDescribe the image in detail.'] * len(num_patches_list)
191responses = model.batch_chat(tokenizer, pixel_values,
192 num_patches_list=num_patches_list,
193 questions=questions,
194 generation_config=generation_config)
195for question, response in zip(questions, responses):
196 print(f'User: {question}\nAssistant: {response}')
197
198# video multi-round conversation (视频多轮对话)
199def get_index(bound, fps, max_frame, first_idx=0, num_segments=32):
200 if bound:
201 start, end = bound[0], bound[1]
202 else:
203 start, end = -100000, 100000
204 start_idx = max(first_idx, round(start * fps))
205 end_idx = min(round(end * fps), max_frame)
206 seg_size = float(end_idx - start_idx) / num_segments
207 frame_indices = np.array([
208 int(start_idx + (seg_size / 2) + np.round(seg_size * idx))
209 for idx in range(num_segments)
210 ])
211 return frame_indices
212
213def load_video(video_path, bound=None, input_size=448, max_num=1, num_segments=32):
214 vr = VideoReader(video_path, ctx=cpu(0), num_threads=1)
215 max_frame = len(vr) - 1
216 fps = float(vr.get_avg_fps())
217
218 pixel_values_list, num_patches_list = [], []
219 transform = build_transform(input_size=input_size)
220 frame_indices = get_index(bound, fps, max_frame, first_idx=0, num_segments=num_segments)
221 for frame_index in frame_indices:
222 img = Image.fromarray(vr[frame_index].asnumpy()).convert('RGB')
223 img = dynamic_preprocess(img, image_size=input_size, use_thumbnail=True, max_num=max_num)
224 pixel_values = [transform(tile) for tile in img]
225 pixel_values = torch.stack(pixel_values)
226 num_patches_list.append(pixel_values.shape[0])
227 pixel_values_list.append(pixel_values)
228 pixel_values = torch.cat(pixel_values_list)
229 return pixel_values, num_patches_list
230
231video_path = './examples/red-panda.mp4'
232pixel_values, num_patches_list = load_video(video_path, num_segments=8, max_num=1)
233pixel_values = pixel_values.to(torch.bfloat16).cuda()
234video_prefix = ''.join([f'Frame{i+1}: <image>\n' for i in range(len(num_patches_list))])
235question = video_prefix + 'What is the red panda doing?'
236# Frame1: <image>\nFrame2: <image>\n...\nFrame8: <image>\n{question}
237response, history = model.chat(tokenizer, pixel_values, question, generation_config,
238 num_patches_list=num_patches_list, history=None, return_history=True)
239print(f'User: {question}\nAssistant: {response}')
240
241question = 'Describe this video in detail.'
242response, history = model.chat(tokenizer, pixel_values, question, generation_config,
243 num_patches_list=num_patches_list, history=history, return_history=True)
244print(f'User: {question}\nAssistant: {response}')