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みなさん、こんにちは。
いしかわつかさです。
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今日は、Stable Diffusionを使ってAIコスプレイヤーを生成する際に、知っておいた方が良い情報をお伝えします。
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- パソコンメンテナンス
- PC入力機器
- PC周辺機器
- 外付SSD
- グラフィックボード
AIイラストを高画素化しよう!
Stable Diffusionは基本的に512✕512に最適化されている(学習をそのサイズでやっていたらしい)為、それ以外のサイズで生成する場合は、バランスが崩れたりする可能性があります。そのため、高画素のデータが欲しいからと言って1920×1080などFHDサイズにするのはご法度です。画像サイズが大きすぎて出力するのに膨大な時間が掛かりますし、そもそもちゃんと生成されません。これは、基本となっている512✕512と大きく差がある為と思われます。それでも、高画素なデータが欲しいですよね?方法はもちろんあります。※ちなみに、高画質になるとは言ってません。
高画素と高画質の違い
勘違いされやすいですが、高画素と高画質は違います。
高画素は512×512→1024×1024のように画素数が高い事を指し、高画質は、画素は同じでも質が上がる事を指します。一般的に混在されやすい要因として、高画質になるには、画素(より多くの情報)が必要となる為、必然的に、高画質なデータは高画素になります。
下記は、全て200×200にリサイズしていますが、元の画素数は50×50、150×150、300×300です。
このように、高画素の方が高画質というのが分かると思いますが、画素を比較すると3枚ともWeb上は200✕200と同じとなります。
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今回のテスト素材
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RAW photo, best quality, realistic, good, happy ,smile, top view, 1 girl, small breasts, slim body,portrait,cute, snow , snow mountain ,snow board <lora:Japanese-doll-likeness:0.25>
paintings, sketches, (worst quality:2), (low quality:2), (normal quality:2), lowres, normal quality, ((monochrome)), ((grayscale)), skin spots, acnes, skin blemishes, age spot, glans
Sampling method | DPM++ SDE Karras |
Sampling Steps | 40 |
Restore faces/Tiling/Highres. fix | |
Width/Height | 512 / 512 |
Batch count/Batch size | 1 / 1 |
CFG Scale | 7 |
Seed | 1389300916 |
Script | None |
高画素化その①【hires.fix】
まずは、「hires.fix」のやり方をご紹介していきます。
hires.fixは、簡単に説明すると独自のアップスケーラを用いて低解像度のデータを高解像度にする機能です。
やり方は簡単です。Hires.fixの欄にチェックを入れます。
チェックを入れると赤枠で囲んだ部分が表示されます。
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- Upscaler:アップスケールする際のプログラム
- Hires steps:アップスケーリング時のsteps数(数値が大きい程高精細になります。)
- Denoising strength:アップスケール時のノイズ除去(1に近づくほどのっぺりします。)
- Upscale by:アップスケールの倍率(2倍が現実的。3倍は僕の環境では処理落ちします。)
ここでも注意事項があります。アップスケールするとアップスケーラーによってイラストが変化します。設定を最小限に抑える事で、元イラストに近い仕上がりで、高画素化出来ます。しかし、処理は重くなるので、極端な高画素化はやはり厳しいです。
Upscaler:None(無)
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Upscaler | Hires steps | Denoising strength | Upscale by | |
---|---|---|---|---|
ORIGINAL | ||||
2nd | None | 0 | 0.01 | 2 |
3rd | None | 50 | 0.01 | 2 |
Upscaler:Latent (bicubic)
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Upscaler | Hires steps | Denoising strength | Upscale by | |
---|---|---|---|---|
1st | Latent (bicubic) | 50 | 0.01 | 2 |
2nd | Latent (bicubic) | 50 | 0.7 | 2 |
Upscaler:SwinIR_4x
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Upscaler | Hires steps | Denoising strength | Upscale by | |
---|---|---|---|---|
1st | SwinIR_4x | 0 | 0.01 | 2 |
2nd | SwinIR_4x | 50 | 0.7 | 2 |
Upscaler:ESRGAN_4x
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Upscaler | Hires steps | Denoising strength | Upscale by | |
---|---|---|---|---|
1st | ESRGAN_4x | 0 | 0.01 | 2 |
2nd | ESRGAN_4x | 50 | 0.7 | 2 |
高画素化その②【Extras】
「Extras」は作成済みのAIイラストを高画質化する方法で、手軽に出来るのがメリットとなっております。
「hires.fix」は単純なアップスケールには向いていない為、元画像をアップスケールするならこちらの方が早くて簡単です。多少画質も向上している印象はあります。
方法は、ウィンドウ上のタブとボタンの2箇所のどちらかをクリックして下さい。
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タブとボタンのどちらでも同じ画面へ移動します。
アップスケールのやり方は、「Scale by resize」の値を変更することで可能です。下図の場合は4倍です。
注意して欲しいのは、アップスケーラーが「None」の場合、僕の環境では、アップスケールしませんでした。同じサイズが出ました。下のように「ESRGAN_4x」でやってみましたが、そのままサイズアップしたので問題ないと思います。
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hires.fixは変化を加える場合に良いかもしれませんね。
変な指も修正される場合がありますので、いい感じに生成されたけど、ちょっと気になる箇所がある場合、ダメ元で試して下さい。
単純な高画素化は、Extrasがいいと思います。もしくは、フォトショップのスーパー解像度やWeb上によくあるサービスサイトですね。
Sampling method 比較
一部から要望があった、サンプリングメソッド(アルゴリズム)による違いをまとめてみました。
僕は専門家じゃないので、それぞれの特徴はよく分かりません。好みでいいと思います。何が正解とか無いんじゃなかな。ちょっと変化をつけたい場合にもいいかもしれませんね。
Sample 1
best quality, 1 girl, smile, detailed beautiful skin, Casual, sporty, dark_hair, resort, cap, bust, soft light
<lora:Japanese-doll-likeness:0.25>
painting,sketches,(worst quality:2),(low quality:2),(normal quality:2),((monochrome)),((grayscale)), missing fingers ,skin spots ,acnes,skin blemishes, nsfw
Sampling method | |
Sampling Steps | 30 |
Restore faces/Tiling/Highres. fix | |
Width/Height | 512 / 512 |
Batch count/Batch size | 1 / 1 |
CFG Scale | 7 |
Seed | 1199297499 |
Script | None |
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Sample 2
(8k, RAW photo, best quality, masterpiece:1.2), (realistic, photo-realistic:1.37),good, happy ,smile, top view, 1girl, portrait,cute, cityscape , night, radiosity, physically-based rendering
paintings, sketches, (worst quality:2), (low quality:2), (normal quality:2), lowres, normal quality, ((monochrome)), ((grayscale)), skin spots, acnes, skin blemishes, age spot, glans
Sampling method | |
Sampling Steps | 50 |
Restore faces/Tiling/Highres. fix | |
Width/Height | 512 / 512 |
Batch count/Batch size | 1 / 1 |
CFG Scale | 10 |
Seed | 4020614860 |
Script | None |
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Sample 3
best quality,masterpiece,ultra high res,(photo realistic:1.4),beautiful lighting, (extremely detailed CG unity 8k wallpaper), detailed beautiful face,detailed clothes,kimono,1 girl cute, young, posing, looking at viewers, professional lighting, physically-based rendering,depth of field
painting,sketches,(worst quality:2),(low quality:2),(normal quality:2),lowers,normal quality,((monochrome)),((grayscale)),skin spots,acnes,skin blemishes,age spot, nsfw,ugly face, fat,missing fingers, extra fingers, extra arms, open chest
Sampling method | |
Sampling Steps | 35 |
Restore faces/Tiling/Highres. fix | |
Width/Height | 512 / 512 |
Batch count/Batch size | 1 / 1 |
CFG Scale | 8.5 |
Seed | 1286431133 |
Script | None |
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Sample 4
(8k, RAW photo, best quality, masterpiece:1.2), (realistic, photo-realistic:1.37),good, happy ,smile, top view, 1girl,Young, small breasts, slim body,portrait,cute, Resort,swim ring
paintings, sketches, (worst quality:2), (low quality:2), (normal quality:2), lowres, normal quality, ((monochrome)), ((grayscale)), skin spots, acnes, skin blemishes, age spot, glans
Sampling method | |
Sampling Steps | 40 |
Restore faces/Tiling/Highres. fix | |
Width/Height | 512 / 512 |
Batch count/Batch size | 1 / 1 |
CFG Scale | 7 |
Seed | 4216616078 |
Script | None |
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まとめ
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ChilloutMixというよりは、Stable Diffusionの説明でした。とりあえず、やってみたというのが趣旨なので、みんなでトライアンドエラーしながら楽しみましょう。本当に凄い時代になりましたね!
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