Rydych chi yn:  > 

Cyfryngau Newydd

Medi 2011

Virtually cleaning a 18th Century painting

Postiwyd gan Graham Davies ar 7 Medi 2011
Golygfa o'r Palazzo Loredan dell'Ambasciatore ar y Gamlas Fawr yn Fenis [cyn glanhau]
Golygfa o'r Palazzo Loredan dell'Ambasciatore ar y Gamlas Fawr yn Fenis [cyn glanhau]
Golygfa o'r Palazzo Loredan dell'Ambasciatore ar y Gamlas Fawr yn Fenis [wedi glanhau]
Golygfa o'r Palazzo Loredan dell'Ambasciatore ar y Gamlas Fawr yn Fenis [wedi glanhau]
» View full post to see all images

Graham Davies, Online Curator, Amgeddfa Cymru - National Museum Wales

When a member of the Art department approached me to ask if I could feature two views of the same painting online — one version covered in dirt and yellowed varnish (as the painting was when it came into the Museum), and the other version showing hidden detail and crisp colours (after being cleaned by Museum conservators) — I realised it would make a perfect interactive if you could use your mouse to virtually 'clean' the dirty canvas to reveal the clean version underneath.

Guardi's view of the Grand Canal, Venice

The painting in question is Francsesco Guardi's View of the Palazzo Loredan dell'Ambasciatore on the Grand Canal, Venice, painted around 1775-85.

Acquired by Amgueddfa Cymru in 2011, this painting is an important acquisition as Guardi's Venetian views are regarded as highly significant in the history of landscape painting.

You clean the painting

To make the most out of this dramatic before and after view, I needed to work out a way of 'virtually' cleaning the painting online by dragging a mouse over the dirty image to reveal the original details and colours previously hidden underneath the dirt and old varnish.

Reinvent the wheel?

I wanted something that allowed the mouse to act as an eraser; allowing one image to be rubbed out to reveal a secondary image underneath. A hunt around the internet brought up the required functionality already created by by Jonathan Nicol (www.f6design.com/journal).

The next step was to acquire high resolution copies of both dirty (before) and cleaned (after) digital images of the artwork from the Photography department.

Precisely aligning two slightly different angled photographs of the same picture

When I opened these digital images in Photohshop it became apparent that variations in the perspective, and distance of the photographic captures resulted in two images that did not precisely match up once overlaid on top of one another.

After an hour of miniscule adjustments using the image warp feature on Photoshop using the images as separate layers within Photoshop (one set at 50% opacity), I eventually achieved a precise overlaid match.

I abandoned trying to do this at 100% view as the image was so large and the time lag in processing too great to view the results (even for my G5 at 2.44Gz and 8GB RAM). I had to settle for a 25% view that filled my Apple 32" screen)

Once I had a satisfactory matched up and aligned the 'dirty' layer on top of the 'clean' layer, I could create the two corresponding TIFF images to incorporate into the Flash file as a basis for the interactive.

After a bit of tweaking, fiddling, and constant testing, I managed to create a simple interactive, allowing you to use your mouse to erase the dirty image, revealing the clean one underneath .

Exploring the detail.

I then decided to repeat this process to create several versions, all using crops of the high resolution images to show close up details of the painting.

Areas of particular interest I choose to separate out were people rowing a goldola, the architectural detail of the buildings, and the detail of the sky and clouds where much original detail had been almost totally obscured by years of grime, dirt and previous 'touch-ups' to the painting. The clean version revealed original intricate details and brushwork.

Future applications for Museum archives and collections

I am hoping this functionality can be utilised for other online images of the collections in the future. Ideas I have at the moment are to reveal hidden under-drawings only visible under x-ray light — as in the example of Richard Wilson's Dolbadarn Castle (NMW A 72), which has been painted over a portrait of a woman, and Landscape with Banditti around a Tent (NMW A 69) which he painted over a Venetian-style reclining nude.

Additional ideas include viewing a landscape or post industrial townscape that can be erased to reveal a historical image underneath...

  • Amgueddfa Genedlaethol Caerdydd

    Amgueddfa Genedlaethol Caerdydd

    Cewch ddarganfod celf, daeareg a hanes natur. Gyda rhaglen newidiol o arddangosfeydd a digwyddiadau, mae rhywbeth i syfrdanu pawb, beth bynnag sy'n mynd â'ch bryd — ac mae mynediad am ddim!

  • Sain Ffagan Amgueddfa Werin Cymru

    Sain Ffagan

    Sain Ffagan yw un o brif amgueddfeydd awyr agored Ewrop, ac atyniad ymwelwyr mwyaf poblogaidd Cymru.

  • Big Pit Amgueddfa Lofaol Cymru

    Big Pit

    Pwll glo go iawn yw'r Pwll Mawr, ac un o amgueddfeydd mwyngloddio gorau Prydain.

  • Amgueddfa Wlân Cymru

    Amgueddfa Wlân Cymru

    Mae Amgueddfa Wlân Cymru, sydd yn hen ffatri wlân y Cambrian Mills, yn lle arbennig ac mae ganddi stori gyfareddol i'w hadrodd.

  • Amgueddfa Lleng Rufeinig Cymru

    Amgueddfa Lleng Rufeinig Cymru

    Yn OC75, sefydlodd y Rhufeiniaid caer yng Nghaerllion a fyddai'n gwarchod yr ardal am dros 200 o flynyddoedd. Heddiw, yn Amgueddfa Lleng Rufeinig Cymru yng Nghaerllion, byddwch yn dysgu pam yr oedd byddin y Rhufeiniaid cymaint i'w hofni.

  • Amgueddfa Lechi Cymru

    Amgueddfa Lechi Cymru

    Mae'r Amgueddfa Lechi'n cynnig diwrnod llawn mwynhad ac addysg mewn ardal ddramatig o brydferth ar lan Llyn Padarn.

  • Amgueddfa Genedlaethol y Glannau

    Amgueddfa Genedlaethol y Glannau

    Mae Amgueddfa Genedlaethol y Glannau yn adrodd hanes diwydiant ac arloesi yng Nghymru, heddiw a thros y 300 mlynedd diwethaf.

  • Rhagor: Archwilio'r Casgliadau

    Gwefan newydd cyffrous yw 'Rhagor' lle cewch ddysgu rhagor am ein casgliadau hynod.