200821742 九、發明說明： 【發明所屬之技術續g j 特別是指於逆先攝=光!=光燈控制系統與方法^ 後再利用閃光燈補光的拍攝方法/、’、圈級數差異 【先前技術】 在i行拍#、、、k，逆光攝影是最難掌控 -，比如在戶外拍攝的人面對陽光或是其攝= 攝的人麵光或是其他光源，故通常拍攝的 2先燈“其他光源’讓所需要的主體不會因為逆Γ的狀 悲而產生無法辨識的黑影，而習知的數位相機缺崎 用閃燈去拍攝良好對比的設定功能’往往會因為^ 係造成背景過曝的現象。 _先的關200821742 IX. Invention description: [Technology of invention belongs to continuation gj Especially refers to the method of shooting in the reverse light = light! = light control system and method ^ then using flash to fill light /, ', the difference in the number of turns [previous Technology] In the i line shooting #,,, k, backlight photography is the most difficult to control - for example, people who shoot outdoors face the sun or the camera light or other light source, so usually shoot 2 The light "other light source" allows the required subject to not produce unrecognizable black shadows due to the retrograde sorrow, while the conventional digital camera lacks the flash to shoot a good contrast setting function 'often because Causes the background to be overexposed.
當運用閃光燈進行拍攝時，錢值配合閃光燈 燈指數（Guide Number，GN值）即成為重要的調校參 其中，光圈值專於焦距除以有效孔徑（光圈值=焦距/有 效孔徑），是數位相機規格中的f值，用來調整拍攝時單位 時間的進光量，一般光圈以f/8、F8等方式來標示，其反 映了拍攝時的進光量。 〃 而GN值，每一個閃光燈的強度並非一致，對於一般 消費型數位相機所掛載的閃光燈而言，閃光燈強声為定 值，不能調整，故能夠左右曝光的是照射距離與光圈的大 小。閃光燈強度用此GN值來表示，閃光燈指數等於被攝When shooting with the flash, the value of the flash with the flash number (Guide Number, GN value) becomes an important tuning. The aperture value is specific to the focal length divided by the effective aperture (aperture value = focal length / effective aperture), which is digital. The f value in the camera specification is used to adjust the amount of light entering per unit time during shooting. Generally, the aperture is marked by f/8, F8, etc., which reflects the amount of light entering during shooting. 〃 And the GN value, the intensity of each flash is not the same. For the flash mounted on a general consumer digital camera, the flash sound is fixed and cannot be adjusted, so the exposure distance and the aperture size can be left and right. The flash intensity is represented by this GN value, and the flash index is equal to the shot.
物的物距乘上光圈值（GN二distance X Aperture)，GN 200821742 Ί且四疋/取小丨Μ兀又凹疋，M'J很1砰奶物距邀 /、光圈信成斤 比，距離數字越大（主體較遠），光圈值Γη八 ^ |旦愈小（則， 圈愈大，一定時間内進光量愈多，為反比的關' 若對於GN值愈大的閃光燈，其閃光量輪出俞大，°，，’ 較遠的主體。 ，可照明 請參閱第一圖所示的閃光燈指數計算示意圖，其中#、 以閃光燈10配合某感光度（ISO值）的gn值等於22為 例，若被攝者a離閃光燈10有3米的距離，則較彳圭_光^目 值為11 ( GN值32除以距離3 ) ’或表達為f/i丨；若被攝者 b離閃光燈10為4米的距離，則較佳光圈值為8 (gn值 32除以距離4)，或表達為f/8 ;若被攝者c離閃光燈1〇為 8米的距離，則較佳光圈值為4 ( GN值32除以距離8)= 或表達為f/4，並以此類推。The object's object distance is multiplied by the aperture value (GN 2 distance X Aperture), GN 200821742 Ί and four 疋 / take a small 丨Μ兀 and concave, M'J is 1 砰 milk from the invitation /, the aperture letter is the ratio, distance The larger the number (the farther away from the subject), the smaller the aperture value Γη八^ | Dan (the larger the circle, the more the amount of light in a certain period of time, the inverse of the ratio). For a flash with a larger GN value, the amount of flash Turn out Yu Da, °,, 'The farther subject. For illumination, please refer to the flash index calculation diagram shown in the first figure, where #, with flash 10 with a certain sensitivity (ISO value) gn value is equal to 22 For example, if the subject a is 3 meters away from the flash 10, then the value is 11 (the GN value is 32 divided by the distance 3) ' or expressed as f/i丨; if the subject b The distance from the flash 10 is 4 meters, and the preferred aperture value is 8 (gn value 32 divided by distance 4), or expressed as f/8; if the subject c is 8 meters away from the flash, then The best aperture value is 4 (GN value 32 divided by distance 8) = or expressed as f/4, and so on.
拍攝時，若處於逆光的狀況下，主體物通常為較暗的 情況，為了避免此情況發生，通常在拍攝時需要先考虞、f 景與背景的光亮度，此時可利用閃光燈進行補& (back-lighting compensation )，讓主體物能清楚呈現，戍 如以下幾種習知技術所提出在逆光情況下的拍攝方式。 在面對逆光情況下的攝影時’習知技術提出多種不同 的方案，較早如美國專利第4,690,536號即已揭露在逆光 情況下應用閃光燈的方法，其為一種使用相機閃光燈的曝 光控制裝置，在拍攝時先測量被攝主體的亮度，再測量& 了被攝主體以外區域的梵度’如背景’接著藉由被攝主體 與背景的亮度在逆光的情況產生一個過曝光 (over-exposure)的情形，達到在逆光的情況下能平衡閃 6 200821742 光、背光與一般光源的曝光控制目的。 更有美國專利第6,950,141號所提供的可以控制影像 感測器曝光的相機，不論在前光（front-lighted)、後光 (back-lighted)或有過亮光線的情況下獲得一個較平均的 曝光量，特別是將有被攝物的晝面分為64個部份，相機則 對此64個部份計算平均亮度，包括影像上半部的平均值、 下半部的平均值與其他不同考量的平均值，藉以控制影像 感測器的曝光量。 再請參閱美國專利公開案第20040101296號所揭露具 有曝光控制功能的相機，此相機包括有可判斷是否影像處 於逆光狀態的逆光調整功能，此功能係比較利用亮度測量 表（photometry)量測的全部影像平均亮度與一個距離以 外的被攝物的亮度後，相機則執行一個適當的曝光控制， 並可利用閃光燈補光，以此在逆光的拍攝下仍能得到適當 曝光的影像。 以習知方式來說，在逆光攝影的情況下，可能（〗）利用 調整影像拍攝裝置的曝光值（EV值）使前景有較大的曝 光值，或(2)利用閃光燈進行對前景（被攝主體）的補光。 以閃光燈的補光方式而言，因為影像拍攝裝置（如數位相 機）將由測得的曝光值判斷一個光圈值，此光圈值可能無 法與閃光燈進行適當的調整而使背景部份過分曝光，故本 發明提出一種針對光圈值的修正來進行逆光拍攝的方法。 【發明内容】 不同於習知技術所揭露在逆光下的拍攝方法，本發明 200821742 逆光攝影之閃光燈控制系統與方法係為先進行前景與背景 的測光，利用影像拍攝裝置設定背景與前景的光圈級數， 再利用閃光燈補光的拍攝方法。 其中逆光攝影之閃光燈控制系統之較佳實施例包括有 閃光單元，其可為附掛於影像拍攝震置上的閃光燈，並 且其閃光燈指數為可調整；另有一測光單元，其係為針對 被攝物進行測光的裴置；再有一光圈調整單元，係於測光 與進行背景與前景的光圈設定之後，用以調整光圈孔徑大 小，控制曝光量；再有一影像擷取單元，係經對焦後利用 如同CCD、CMOS等影像感測元件透過鏡頭操取影像，再 將所擷取之影像轉換為數位訊號；再有_記憶單元，係可 =拍攝過程中先暫存所擷取的影像、記憶㈣值與光圈值 寻拍攝需要的參數、儲存所拍攝完成的數位檔案。 取後，在影像拍攝裝置中聯絡各單元並控制各單元作 動的中央處理單兀’其巾包括各種完成本發餐逆光攝影 下的閃光燈少有光圈決定單元、物距計算單 元、GN值計算單元等。 而/、逆光攝衫之閃光燈控制方法之較佳實施例包括先 拍攝的前景進行測光，根據偵測到的曝光值得出前 弟、，光圈值’接著針對背景部份測光，同樣測得-曝 — 景的第二值；之後依所需的逆光效果 景的光圈級數差異，即第—光圈值與第二光 的㈣ϋ，之後進行對焦，並依成像公式計算得出前景 的 根據上述第一光圈值與第二光圈值之差值所得 、 利用閃光燈指數等於物距乘上光圈值的關係得 8 200821742 出閃光燈的閃光燈指數，最後以預先設定的快門值、光圈 值並配合閃統指數的閃光燈補光以進行拍攝。 【實施方式】 β本發明係為-種逆光攝影之閃光燈控制系統與方法， 是指於逆光攝影時，可以藉由影像拍攝裝置（較佳實施例 為數位相機）内設定背景與前景的光圈級數差值，再利用 閃光燈進行補 如在戶外的攝影者面對陽光或是其他光源，而被拍攝 !!人ί對陽光或是其他光源，通常於拍攝時需要補上閃光 燈或是其他光源，讓所需要的主體不會因為逆光的狀態而 產生热法辨識的黑影，故本發明所提供的閃光燈控制系統 ^=法先藉由測光儀器或是拍攝裝置本身的測光功能得知 砒景與背景的曝光值（EXp0sure Value, EV值），包括快門 ^shutter)與光圈值（aperture)等，之後經決定前景與背 景所要的亮度差值或光圈級數，而得出一逆光拍攝的光圈 值，再於拍攝時藉閃光燈補光得出一照片。 :般來說’在逆光攝影的情況下’使用者多半利用閃 拍景（被攝主體）的補光’或是直接調整影像 為旦= 值。在使用閃光燈進行補光的方式中，因 光裝置將由測得的曝光值判斷-個光圈值，而此 相值可㈣法與閃光燈進行適當的協調 光不夠而仍使前景產生黑影，故本發： _====方法係為-種針對* 200821742 利用閃光燈指數所進行的拍攝方法請參閱第二圖所示 為一在黑暗環境下的拍攝流程： 的拍攝能力限制光圈大小，光圈值通常以 2, 2.8, 4, 5.6, 8, 11，16等數字，數字愈大， 在一般快門優S (shutter pri〇rity)的拍攝過程中，快 門值為優先設定’接著需要決定-相值來進行拍攝，通 常藉由曝光值的偵測後推算出應有的光圈大小，更♦要配 合影像拍攝裝置本身的物理（硬體）限制，影像拍ς裝置When shooting, if the subject is in a backlight condition, the subject is usually dark. To avoid this, the brightness of the scene and the background must be checked before shooting. (back-lighting compensation), so that the subject can be clearly presented, such as the following methods of shooting in the case of backlighting. In the case of photography in the case of backlighting, the prior art has proposed a variety of different solutions. The method of applying a flash lamp in the case of backlighting has been disclosed as an exposure control device using a camera flash, as disclosed in U.S. Patent No. 4,690,536. When shooting, first measure the brightness of the subject, then measure & the van Gogh's area outside the subject, such as the background, and then over-exposure by backlighting the brightness of the subject and the background. In the case of backlighting, it is possible to balance the exposure control of the light, backlight and general light source in the case of backlighting. There is also a camera that can control the exposure of an image sensor provided by US Pat. No. 6,950,141, which obtains a more average in front-lighted, back-lighted or over-bright light. The amount of exposure, especially the face of the subject is divided into 64 parts, and the camera calculates the average brightness for the 64 parts, including the average of the upper half of the image and the average of the lower half. The average value of the measurement to control the exposure of the image sensor. Please refer to the camera with exposure control function disclosed in U.S. Patent Publication No. 20040101296, which includes a backlight adjustment function for determining whether an image is in a backlight state, and this function compares all measured by photometry. After the average brightness of the image and the brightness of the subject other than one distance, the camera performs an appropriate exposure control and can use the flash to fill the light, so that the appropriate exposure image can still be obtained under backlight shooting. In a conventional manner, in the case of backlight photography, it is possible to adjust the exposure value (EV value) of the image capturing device to make the foreground have a larger exposure value, or (2) use the flash to perform the foreground ( The subject's fill light. In terms of the fill mode of the flash, because the image capture device (such as a digital camera) will determine an aperture value from the measured exposure value, the aperture value may not be properly adjusted with the flash to overexpose the background portion. The invention proposes a method for performing backlight shooting for correction of the aperture value. SUMMARY OF THE INVENTION Unlike the conventional method for photographing under backlight, the 200821742 backlight control system and method for backlighting is to perform foreground and background metering, and use the image capturing device to set background and foreground aperture levels. Count, and then use the flash to fill the shooting method. A preferred embodiment of the flash control system for backlighting includes a flash unit, which can be a flash attached to the image capture, and the flash index is adjustable; and a light metering unit for shooting The device performs metering; there is an aperture adjustment unit, which is used to adjust the aperture aperture size and control the exposure amount after metering and setting the aperture of the background and foreground; and then an image capturing unit is used after focusing. The image sensing component such as CCD and CMOS can capture the image through the lens, and then convert the captured image into a digital signal; and then have a _memory unit, which can temporarily store the captured image and memory (four) value during the shooting process. Find the parameters required for shooting with the aperture value, and store the digital files that have been taken. After taking it, the central processing unit that contacts each unit in the image capturing device and controls the operation of each unit includes a variety of flashes under the backlight for completing the present meal, a small aperture determining unit, an object distance calculating unit, and a GN value calculating unit. Wait. And the preferred embodiment of the flash control method of the backlighting camera comprises the first shooting of the foreground for metering, the previous exposure based on the detected exposure value, the aperture value 'and then the background part of the metering, the same measured - exposure - The second value of the scene; then the difference in the aperture level of the desired backlighting scene, ie the first aperture value and the second light (four) ϋ, then focus, and calculate the foreground according to the first aperture according to the imaging formula The difference between the value and the second aperture value, using the flash index equal to the object distance multiplied by the aperture value is 8 200821742 flash flash index, and finally with the preset shutter value, aperture value and flash with the flash index Light to shoot. [Embodiment] The present invention is a flash control system and method for backlight photography, which means that the background and foreground aperture levels can be set in the image capturing device (the preferred embodiment is a digital camera) during backlight photography. The difference between the number and the flash is used to make the outdoor photographer face the sun or other light source, and is shot!! People ί to the sun or other light sources, usually need to make up the flash or other light source when shooting. The required flashing body does not generate thermal shadows due to the state of backlighting. Therefore, the flash control system provided by the present invention first learns the scene by the photometric instrument or the photometric function of the photographing device itself. The background exposure value (EXp0sure Value, EV value), including the shutter ^shutter) and the aperture value (aperture), etc., after determining the brightness difference or the aperture level of the foreground and the background, and obtaining the aperture value of the backlight shot. Then, when shooting, use the flash to fill the light to get a photo. : Generally speaking, in the case of backlight photography, the user mostly uses the fill light of the flashing scene (the subject) or directly adjusts the image to a value of ≥. In the method of using the flash to fill light, the light device will judge the aperture value from the measured exposure value, and the phase value can be properly coordinated with the flash light, and the foreground light is still insufficient. Hair: _==== Method is for - kind of target * 200821742 The shooting method using the flash index, please refer to the second picture shows the shooting process in a dark environment: the shooting ability limits the aperture size, the aperture value is usually With numbers such as 2, 2.8, 4, 5.6, 8, 11, 16 and so on, the larger the number is, the shutter value is set preferentially during the shooting process of the general shutter s (shutter pri〇rity), and then the decision-phase value is required. Shooting, usually by the detection of the exposure value to calculate the desired aperture size, more important to match the physical (hard) limitations of the image capture device itself, the image capture device
f值表達，包括 光圈開啟愈小。 於快門值決定後（步驟S201)，於影像拍攝裝置對準 被攝物後，進行齡，通常是_半_門鍵來進行對隹 (步驟 S203 ); 之後’依成像公式計算取得的被攝物的物距（p)，此 時鏡頭中鏡片被驅錢行對焦，因為理球面鏡的 成像公式為l/p+l/q= l/f，其中物距、q為像距、f 為焦距，一旦對焦完成，即得知焦距f / ^ ^ , 測器與球面鏡的距離）亦為可知，故可^ q , ^ ^ ，娜)； …易得知物距K步 接著進行光圈值的判斷，在此實施例下，光圈值與閃 光燈的發光量息息相關，閃光燈的發光量通常以閃光燈指 數（GN幻來表不，除了自動閃光燈以外…般閃光燈 的光量-定，故能夠左右曝光程度的是上料算之物距與 光圈的大小。問光燈指數等於物距乘上光圈值（GuMe Number Distance X APmure) ’也就是使用閃光燈時， 其曝光的GN值料閃紐職攝體恤_當時使用光 圈值的乘積，㈣燈指數數钱A，表示閃光量輸出越大。 10 200821742 =广例中’由於閃光燈的閃光燈指數為已知，故 主體物距，取得該光圈值（步驟 已經決定的快門值與此光圈值進行拍攝（步驟s2〇9)。據 逆光==閃光燈指數推算光圈值的方式若應用於—般 情況下’如白天背對光源(如太陽）的拍攝情 、乐一圖所不的本發明之較佳實施例之流程圖。 S3〇/^施例^門值於拍攝前已決定（步驟 攝的主-1旦因為本實施例是逆光攝影’故先對所欲拍 光功/\(^、）進行測光’可利用影像拍攝裝置内的測 =力犯，或利用獨立的測光錶針對前景測光，測光是⑽ 置根剔貞_的光_出曝絲，也就是涵物 提供—組快門值與光圈值等參數，此例係 于出刚，7、的第一光圈值（步驟S303 ); 景在較亮⑽況’再針對背景部份測光，同 :二 由測光的結果得出背景的第二光 接著’本發明所提供的閃光燈控制系統與方法係由使 g松友所而的逆光效果設定背景與前景的光11級數差異， 弟光圈值與第二光圈值的差異（步驟S307); 情況ΐ S307中設定光圈級數差異的步驟中，可能產生的 (1)拍攝時的光圈值係依據級數調大的背景光圈值， 其中背景的光圈級數會於設定後調大，但仍比前 :景的^圈級數小（孔徑較小），以此光圈值進行拍 攝，前景經過閃光燈補光，背景則因光圈調大而 200821742 有光的現象，舉例來說，將背景的第二光圈 值设定比被攝物的第一光圈值大一級，如測得光 圈f/8時，則調到f/5 6，使背景產生過曝光的情 ^而月不在多數情況下並不會受到閃光燈對前 斤、的補光動作而有增加曝光的影響 (2) 拍$時的光圈值係依據測量出的背景光圈值，其 中背景光圈級數仍比前景的光圈級數小，則曝光 不足的部份係利用閃光燈進行補光； (3) 拍，=的光圈值係依據級數調小的前景光圈值， f日寸刚景需以閃光燈進行補光，使前景有清晰且 凴的影像； (4) 拍，時的光圈值係依據級數調大的背景光圈值及 =守、’及數调小的前景光圈值，此時前景將曝光不 〜再以閃光燈進行補光，使前景有清晰且亮的 衫像。 ――於上述步驟巾的光圈級數差異的設定方法巾， 像拍縣置的㈣魏上進行設I如装 行ι Γ 觀級數差異，或是由其他狀書面進 仃…猎以設定前景與背景所需要的光圈級數差1;進 隹it行對焦’影像拍攝裝置對準被攝物以進行對 :利機、自動數位相機内建對焦的功 的進行對焦’或其他產生相同對焦功效 景)====_算得出被攝物(前 係由已知的像距（dmancetoimage)與焦距 12 200821742 (stance t0 focus)得知物距（出他咖t〇 〇b㈣）（步驟 S 311 )， 根據上述第一光圈值與第二光圈值之差值所得的 二=:，並利用閃光燈指數等於物距乘上光圈值的關 $ =閃光燈關紐指數，亦即決定閃紐所產生的補 ^度（步驟S313)’最後以上述快門值、光圈值並配人 閃光燈指數的閃光燈補光以進行拍攝（步驟s3i5)。。 =例來說，歧行戦，可由影像拍攝裝置直 =由測光錶實地測光，如測_ 職，雨景為f/4、快門為職， 影像拍攝裝置的内建功能設定背景比前景亮1 一級），表示背景與前景所差的光圈值 ^ [、、、動作，亚依成像公式計算出前景距離為3米，此 = =圈值5.6係咖 ί :订心〜月豕光圈大一級，即由f/8改為f/56， 相較於正常曝光為過曝光（崎哪。_)。 . 所列= ^計算閃光燈強度，由於原本前景 :使用為f/5.6，就用閃光燈補光， ?為:制f/4’就於光圈在f/56時補f/4的亮度 C f/4+f/扣f/5.6 )，故GN值等於3(距離）乘上 圈 麵找一，按下快門鍵拍舰 王月厅、比刖景免一級的照片。 同理’在前景與背景曝光值差異更大的環境下，可設 疋更大光圈值差異的逆光拍攝效果。 13 200821742 第四圖揭露本發明逆光攝影之閃光燈控制系統，係用 於影像拍攝裝置中，藉設定前景與背景之光圈值差異來進 行逆光情況下的拍攝，達成逆光攝影的特殊效果，為達成 本發明之目的，此閃光燈控制系統至少包括閃光單元41、 測光單元42、光圈調整單元43、影像擷取單元44、記憶 單元46與控制各單元的中央處理單元400等，各單元敘述 如下： 閃光單元41係為該影像拍攝裝置在逆光拍攝時用於 補光之裝置，可為附掛於影像拍攝裝置上的閃光燈，其較 佳實施例為一可調整亮度的閃光燈，即其閃光燈指數為可 調整；另一實施例為其閃光燈指數為固定之閃光燈； 測光單元42係為針對被攝物進行測光的裝置，其中較 佳實施例為内建於影像拍攝裝置内的測光錶，另一實施例 可為獨立運作的測光錶，用以對被攝物測量曝光值的裝置； 光圈調整單元43係為影像拍攝裝置内控制曝光量控 制的單元，於測光與進行背景與前景的光圈設定之後，用 以調整光圈孔徑大小的部份，控制曝光量； 影像擷取單元44係驅動影像拍攝裝置之鏡頭（包括必 要之鏡片組），經對焦後利用裝載於影像拍攝裝置的電荷耦 合裝置感應器（CCD)或互補式金氧半導體感應器（CMOS) 等影像感測元件擷取影像，接著將所擷取之影像進行光電 轉換，轉換為數位訊號，所擷取的影像可區分為前景與背 景； 記憶單元46可於拍攝過程中先暫存（buffer)由影像 、搦取單元44所擷取的影像，並可記憶進行測光後所得出前 14 200821742 景與背景㈣光值，與其快門值與光圈值等減需要的來 數，另外，更可儲存所拍攝完成的數位檔案； 曰中央處理單力_係控制上述各單元之仙，可為一 晶片所達成，至少包括下列裝置： a·光圈決定單元4〇2，於本發明之較佳實施例中，係 利用測光單元42分別偵測前景與背景的曝光值， 並分別得出不同的第一光圈值與第二光圈值，因為 處於逆光拍攝的情況，故第二光圈值（背景較亮， 所測得的光圈孔徑較小）應大於第一光圈值（前景 較暗’所測得的光圈孔徑較大），本發明再利用光 □决疋單元402設定前景與背景的光圈差值，並於 設定後’光圈調整單元43調整光圈孔徑大小的部 伤’以控制曝光量，藉以拍攝出所需要的逆光效 果’其中設定方法之實施例可於影像拍攝裝置的内 建功能上進行設定，藉以設定前景與背景所需要的 光圈級數差異； b•物距計算單元403係於對焦之後，依照成像公式計 鼻被攝物（前景）的物距； c· GN值計算單元4〇5，根據上述光圈決定單元4〇2 所設定拍攝時的光圈值，並根據前文所提及之在半 才文對焦時依成像公式所計算得出之被攝物（前景） 的物距，即可利用閃光燈指數等於物距乘上光圈值 之公式推算出閃光燈指數，接著中央控制單元400 便控制影像擷取單元44擷取影像，並將影像儲存 於储存單元46中，以達到本發明之目的； 15 200821742 特別的是，上述光圈決定單元402、物距計算單元403 與GN值計算單元405等數值計算單元之功能可由設置於 影像拍攝裝置中的韌體（ firmware)達成，該韌體為一記 載有執行上述各功能的程式的晶片。 綜上所述，本發明為一種逆光攝影之閃光燈控制系統 與方法，係能設定前景與背景的光圈值差異，再配合閃光 燈的補光措施得出特殊的逆光拍攝效果。 惟以上所述僅為本發明之較佳可行實施例，非因此即 拘限本發明之專利範圍，故舉凡運用本發明說明書及圖示 内容所為之等效結構變化，均同理包含於本發明之範圍 内，合予陳明。 【圖式簡單說明】 第一圖所示為閃光燈指數計算示意圖； 第二圖所示為在黑暗環境下的拍攝流程； 第三圖係為本發明之較佳實施例流程圖； 第四圖係為本發明閃光燈控制系統架構圖。 【主要元件符號說明】 閃光燈10 被攝者a 被攝者b 被攝者c 閃光單·元41 16 200821742 測光單元42 光圈調整單元43 影像擷取單元44 記憶單元46 中央處理單元400 光圈決定單元402 物距計算單元403 GN值計算單元405 17The f value is expressed, including the smaller the aperture opening. After the shutter value is determined (step S201), after the image capturing device is aimed at the subject, the age, usually the _half-door key, is performed (step S203); then the image taken by the imaging formula is taken. The object distance (p) of the object, at this time the lens in the lens is driven to focus, because the imaging formula of the spherical mirror is l/p+l/q= l/f, where the object distance, q is the image distance, and f is the focal length. Once the focus is completed, the focal length f / ^ ^, the distance between the detector and the spherical mirror is also known, so it can be known as ^ q , ^ ^ , Na); ... it is easy to know the object distance K step and then judge the aperture value. In this embodiment, the aperture value is closely related to the amount of light emitted by the flash. The amount of light emitted by the flash is usually measured by the flash index (the illusion of the GN is not the same as the amount of light of the flash other than the automatic flash), so the degree of exposure can be left and right. The material distance and the size of the aperture are calculated. The GuMe Number Distance X APmure is the GN value of the exposure when the flash is used. The product of the aperture value, (4) the lamp index counts the money A, indicating 10 200821742 = In the wide example, 'Because the flash index of the flash is known, the subject distance is obtained, and the aperture value is obtained (the shutter value determined by the step is taken with this aperture value (step s2〇9) The method of estimating the aperture value according to the backlight == flash index is applied to the flow chart of the preferred embodiment of the present invention, such as the daytime backlighting of the light source (e.g., the sun). The S3〇/^example^ threshold value has been determined before the shooting (the main photo taken in the step is because the embodiment is backlit photography, so the light is taken for the desired light//(^,)). Shooting in the camera, or using an independent light meter for foreground metering, metering is (10) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ For example, the first aperture value of the original, the first aperture value (step S303); the scene is brighter (10) condition 're-measurement for the background part, the same: two by the result of the light measurement to obtain the second light of the background, then the invention The flash control system and method provided by The backlight effect sets the difference between the background and the foreground light 11 steps, the difference between the aperture value and the second aperture value (step S307); Case ΐ S307 in the step of setting the aperture level difference, may occur (1) shooting The aperture value of the time is the background aperture value that is adjusted according to the number of stages, wherein the aperture level of the background is increased after the setting, but still smaller than the front: the number of the circle of the scene (the aperture is small), and the aperture value Shooting, the foreground is filled with flash, and the background is bright due to the aperture. 200821742 has a light phenomenon. For example, the second aperture value of the background is set to be one level larger than the first aperture value of the subject, as measured. When the aperture f/8 is adjusted to f/5 6, the background will be overexposed. However, in most cases, the moon will not be affected by the flash to the front of the flash, and the exposure will increase (2) The aperture value at the time of shooting is based on the measured background aperture value, wherein the background aperture level is still smaller than the aperture level of the foreground, and the underexposed portion is complemented by the flash; (3) beat, = aperture The value is the foreground aperture value that is adjusted according to the number of stages, f Inch light scene needs to be filled with flash to make the foreground clear and ambiguous; (4) The aperture value of the beat is the background aperture value according to the number of steps and the foreground aperture with small and small numbers Value, at this time the foreground will not be exposed ~ then fill the light with the flash, so that the foreground has a clear and bright shirt image. - In the above-mentioned steps, the method of setting the difference in the aperture level of the towel, such as the shooting of the county (four) Wei on the set of I, such as loading line Γ Γ 级 级 , , , , , , , , , , , , , The difference between the aperture level required by the background is 1; the focus is on the focus image. The image capture device is aimed at the subject to perform the focus on: the focus of the built-in focus of the automatic digital camera, or the other to produce the same focus. Scene) ====_ Calculate the subject (previously by the known image distance (dmancetoimage) and focal length 12 200821742 (stance t0 focus) to know the object distance (out of his coffee t〇〇b (four)) (step S 311 ), according to the difference between the first aperture value and the second aperture value obtained by the second =:, and using the flash index equal to the object distance multiplied by the aperture value of the off = $ flash button index, which is determined by the flash The complement (step S313) 'finally fills the flash with the shutter value, the aperture value, and the flash index of the above-mentioned flash index (step s3i5). For example, the image can be directly detected by the image capturing device. Light metering in the field, such as the test _ job, the rain scene is f / 4, The door is in the position, the built-in function of the image capturing device sets the background brighter than the foreground 1 level), indicating the aperture value of the background and foreground difference ^ [,,, action, Yayi imaging formula calculates the foreground distance is 3 meters, this = = circle value 5.6 system coffee ί: ordering ~ month 豕 aperture a large level, that is, from f / 8 to f / 56, compared to the normal exposure for over-exposure (Saki. _). Listed = ^ Calculate the flash intensity, due to the original prospect: use f/5.6, use the flash to fill the light, ? is: make f / 4 'just fill the f / 4 brightness at the aperture f / 56 C f / 4+f/ buckle f/5.6), so the GN value is equal to 3 (distance) multiplied by the circle surface to find one, press the shutter button to take the photo of the ship's Wang Yue Hall, and the level of the scenery. Similarly, in an environment where the difference between the foreground and background exposure values is larger, a backlighting effect with a larger aperture value difference can be set. 13 200821742 The fourth figure discloses the flash control system for backlight photography of the present invention, which is used in an image capturing device to perform shooting under backlight conditions by setting a difference in aperture value between the foreground and the background, thereby achieving a special effect of backlighting, in order to achieve this. For the purpose of the invention, the flash control system includes at least a flash unit 41, a photometry unit 42, a diaphragm adjustment unit 43, an image capture unit 44, a memory unit 46, and a central processing unit 400 for controlling each unit, and the units are described as follows: 41 is a device for filling light when the image capturing device is used for backlighting, and may be a flash attached to the image capturing device. The preferred embodiment is a brightness adjustable flash, that is, the flash index is adjustable. Another embodiment is a flash lamp whose fixed flash index is fixed; the photometry unit 42 is a device for metering a subject, wherein the preferred embodiment is a light meter built in the image capturing device, and another embodiment may a stand-alone light meter for measuring an exposure value of a subject; the aperture adjustment unit 43 is The unit for controlling the exposure amount in the image capturing device controls the exposure of the aperture of the image capturing device after adjusting the aperture of the background and the foreground, and controlling the exposure amount; the image capturing unit 44 drives the lens of the image capturing device ( Including the necessary lens group), after focusing, the image sensing component such as a charge coupled device sensor (CCD) or a complementary MOS sensor (CMOS) mounted on the image capturing device is used to capture the image, and then the image is captured. The image is converted into a digital signal, and the captured image can be divided into a foreground and a background. The memory unit 46 can temporarily buffer the image captured by the image capturing unit 44 during the shooting process. It can be memorized and measured for the first 14 200821742 scene and background (four) light value, and the shutter value and aperture value are reduced. In addition, the digital file can be stored. 曰 Central processing unit force _ system control The above units can be realized by a wafer, and at least include the following devices: a. Aperture determining unit 4〇2, which is preferred in the present invention. In the embodiment, the photometric unit 42 is used to respectively detect the exposure values of the foreground and the background, and respectively obtain different first aperture values and second aperture values, because in the case of backlight shooting, the second aperture value (background comparison) Bright, the measured aperture aperture is small) should be greater than the first aperture value (the aperture aperture measured by the darker foreground is larger), and the aperture determining unit 402 of the present invention is used to set the aperture difference between the foreground and the background. And after setting, the aperture adjustment unit 43 adjusts the aperture of the aperture size to control the exposure amount, thereby capturing the required backlight effect. The embodiment of the setting method can be set on the built-in function of the image capturing apparatus. The difference between the aperture levels required to set the foreground and the background; b• The object distance calculation unit 403 is the object distance of the nasal subject (foreground) according to the imaging formula after focusing; c· GN value calculation unit 4〇5, According to the above-mentioned aperture determining unit 4〇2, the aperture value at the time of shooting is set, and according to the above-mentioned subject, the subject calculated according to the imaging formula at the time of focusing on the half-character (precursor) The object distance can be calculated by using the formula that the flash index is equal to the object distance multiplied by the aperture value, and then the central control unit 400 controls the image capturing unit 44 to capture the image, and stores the image in the storage unit 46. For the purpose of the present invention; 15 200821742 In particular, the functions of the numerical calculation unit such as the aperture determining unit 402, the object distance calculating unit 403, and the GN value calculating unit 405 can be achieved by a firmware provided in the image capturing apparatus. The firmware is a wafer in which a program for performing the above functions is described. In summary, the present invention is a backlight control system and method for backlighting, which can set the difference between the aperture value of the foreground and the background, and then combines the light-filling measures of the flash lamp to obtain a special backlighting effect. However, the above description is only a preferred embodiment of the present invention, and thus the scope of the present invention is not limited thereto, and equivalent structural changes made by using the present specification and the illustrated contents are equally included in the present invention. Within the scope of the agreement, Chen Ming. BRIEF DESCRIPTION OF THE DRAWINGS The first figure shows a flash index calculation diagram; the second figure shows the shooting process in a dark environment; the third figure is a flow chart of a preferred embodiment of the present invention; It is the architecture diagram of the flash control system of the present invention. [Description of main component symbols] Flash 10 Subject a Subject b Subject c Flash unit 41 41 200821742 Photometry unit 42 Aperture adjustment unit 43 Image capture unit 44 Memory unit 46 Central processing unit 400 Aperture decision unit 402 Object distance calculation unit 403 GN value calculation unit 405 17