Everyone likes high resolution images: researchers look at details in painting to spot repairs and pentimenti. Media creators need high resolution images for print media. And certainly there are scores of laypeople who enjoy getting lost in the details of a painting. Making high quality images available online can be a good way for archives to stand out and attract new users.


 

High quality scanners can be pricey, for example 1200 dpi book scanners sell between £500 and £1000. And even then: some objects, such as paintings, brittle books, or fabrics cannot be used using a standard flatbed scanner, and specialized scanning hardware to scan such objects are out of reach for most small archives.

So, here’s how to create high quality scans without the need for extra hardware. For testing, I created a 620 dpi photograph of one of my acrylic paintings.

What you’ll need:
1. Some digital camera (I used my smartphone’s camera, but anything will do)
2. Adobe Photoshop (you can use the 7 day free trial version)

Move your camera over the object and take a closeup photo of each part of the object. I took 43 photos which look something like this:

If you want to experiment with my photos, you can download them here.

Now create a new image in Photoshop and load all your photos into individual layers. You can find a way to automate this here. But if you have only around 40 images, as I have, you can also just drag them all into Photoshop where you have to confirm the pasting of each image by pressing Enter which will achieve the same.

First rasterize all layers by selecting all layers in the “Layers” window, right-clicking one of the layers, and choosing “Rasterize Layer”.

Then choose “Edit > Auto-Align Layers…” and click Okay in the following dialog. The aligning process can take some hours, for my example it took 6 hours on my machine. Afterwards, my photos look like this:

To remove the differences in brightness across the picture, choose “Edit > Auto-Blend Layers…” and click Okay in the following dialog. The blending process will again take a short while, for me that was 5 minutes. Here is what I got:

As a last step you can remove the perspective distortion. To this end, reduce the image to one layer by right-clicking any layer in the “Layers” window and selecting “Flatten Image”. Afterwards, choose “Edit > Transform > Distort” to pull the corners of the image until the perspective distortion disappears. If you want, you can select “View > Rulers” to help you to make the edges of your image straight.

And here is the end result for me!


如何簡單自製高清掃描

每人都喜歡高清圖像:如研究人員可審視一幅油畫的細節,以找尋復修和原本筆畫的痕跡;而媒體設計師則需要高清圖像用於打印上;當然也有很多外行人純粹樂於觀賞繪畫的細節。故此,使用高清圖像可能是讓檔案庫吸引多些新的使用者的好方法。

高清的掃描器可能所費不菲,例如達 1200 清晰度(dpi)的書本掃描器的價位就介乎500至1000英鎊。不過,普通的平板掃描器難以應用在某些物品上(例如油畫脆弱的書籍或織物),而大多數小型檔案館亦難有足夠資源採購專門的掃描器材來掃描此等物品。

這裡我們為您們介紹無須額外器材即可創建高清掃描的方法。是次測試拍攝了我其中一幅廣告彩畫作,620 dpi(清晰程度達商業用途級別)的照片。

您需要:
1. 單反相機(手機也可)
2. Adobe Photoshop (可用7天試用版)

把您的相機移近拍攝的物件,拍一連串的近距離照片。我拍了共43 張照片,如下:

您可下載這些相片嘗試以下的步驟。

首先在Photoshop中按新圖像,然後把所有照片加載到不同的圖層;您可按此學習如何讓電腦自動執行此操作。或者,如您像我一樣只有40張圖片,您也可以將它們全部拉到Photoshop中,並按Enter確認每張圖片的貼上,出來的效果是一樣的。

之後,在「圖層」視窗中選擇所有圖層,右鍵單擊其中一圖層,然後選擇「柵格化圖層」。
接著,選擇「編輯>自動對齊圖層…」,然後選「確定」。對齊過程可能要花幾個小時,例在我的電腦上就需要6個小時,出來效果如下:


要統一圖片的不同亮度,選
編輯>自動混合圖層…然後選確定。混合的過程將再花一點時間,對我來說是5分鐘。效果如下:

 

最後,您可以弄正圖片。先在「圖層」右鍵單擊任意一圖層,選「合併圖層」,將不同圖層變為一層。然後,按「編輯>變換>變形」,拉動圖像的各個角點,直到圖片看起來比較正常。如有需要,可按「視圖>標尺」弄直圖邊。

做完以上步驟後,高清圖像便完成了!