ollama/model/models/deepseekocr/imageprocessor.go

84 lines
2.4 KiB
Go

package deepseekocr
import (
"bytes"
"image"
"image/color"
"math"
"slices"
"golang.org/x/image/draw"
"github.com/ollama/ollama/ml"
"github.com/ollama/ollama/model/imageproc"
)
type ratio struct {
x, y int
}
func ProcessImage(ctx ml.Context, bts []byte) (ml.Tensor, ml.Tensor, []int, error) {
img, _, err := image.Decode(bytes.NewReader(bts))
if err != nil {
return nil, nil, nil, err
}
minNum, maxNum, imageSize, baseSize := 2, 9, 640, 1024
var targetRatios []ratio
for n := minNum; n <= maxNum; n++ {
for i := 1; i <= n; i++ {
for j := 1; j <= n; j++ {
if i*j <= maxNum && i*j >= minNum && !slices.Contains(targetRatios, ratio{i, j}) {
targetRatios = append(targetRatios, ratio{i, j})
}
}
}
}
targetRatio := findBestAspectRatio(targetRatios, img.Bounds().Dx(), img.Bounds().Dy(), imageSize)
targetWidth, targetHeight := imageSize*targetRatio.x, imageSize*targetRatio.y
blocks := targetRatio.x * targetRatio.y
mean := imageproc.ImageNetStandardMean
std := imageproc.ImageNetStandardSTD
var patches []float32
resized := imageproc.Resize(img, image.Point{X: targetWidth, Y: targetHeight}, imageproc.ResizeBilinear)
for i := range blocks {
patch := image.NewRGBA(image.Rect(0, 0, imageSize, imageSize))
draw.Draw(patch, patch.Bounds(), resized, image.Point{
X: i % (targetWidth / imageSize) * imageSize,
Y: i / (targetWidth / imageSize) * imageSize,
}, draw.Over)
patches = append(patches, imageproc.Normalize(patch, mean, std, true, true)...)
}
img = imageproc.CompositeColor(img, color.Gray{})
img = imageproc.Pad(img, image.Point{X: baseSize, Y: baseSize}, color.Gray{127}, draw.BiLinear)
return ctx.Input().FromFloats(patches, imageSize, imageSize, 3, blocks),
ctx.Input().FromFloats(imageproc.Normalize(img, mean, std, true, true), baseSize, baseSize, 3),
[]int{targetRatio.x, targetRatio.y},
nil
}
func findBestAspectRatio(targetRatios []ratio, width, height, imageSize int) ratio {
bestDiff := math.MaxFloat64
best := ratio{1, 1}
realRatio := float64(width) / float64(height)
for _, target := range targetRatios {
targetRatio := float64(target.x) / float64(target.y)
diff := math.Abs(realRatio - targetRatio)
if diff < bestDiff {
bestDiff = diff
best = target
} else if diff == bestDiff {
if float64(width*height) > 0.5*float64(imageSize*imageSize*best.x*best.y) {
best = target
}
}
}
return best
}